BFS has officially gone integrated amp crazy. In the last few issues, MGD and Rich Weiner have taken a look at some interesting new units from the Far East. In this installment I survey three models ranging in price from $500 to $2800 each possessing a unique combination of attributes and strengths, they are: the Dussun DS99, the April Music Stello AI320 and the NuForce IA-7.

When one mentions integrateds in these pages, one must pay proper respect to the original BFS benchmark: the Bryston B-60. An MGD favorite going back to his original review a decade ago, it was a prime mover in taking integrateds to a new level of audiophile respectability.

My own experience with a B-60 several years ago was mixed. Fresh out of college I purchased a used one to go with my newly acquired Merlin TSM-SE’s. It was a nice amp but somehow didn’t do it for me, and I wound up selling it. When this new crop of integrated amps arrived, I was certain that their performance was at least on the level of, and probably better than the B-60 from yesteryear. I told this to MGD, who proceeded to dig up his original B-60 review unit to challenge my assertion. Comparisons to it were inevitable, so why leave them to pure conjecture based on fuzzy old memories? The integrated amp battle royal was on.

Some testing notes: Speakers on hand were my Merlin TSM-MX’s and Silverline Preludes, an excellent little floor-stander ($1200, review forthcoming). Source components included the Stello CDA320 CD player and a Sony C222ES SACD player modified by yours truly. In addition to the Bryston integrated, the "reference" separates for comparison were the Edge G6 and ME 550 II amplifiers driven by a MSB Gold MVC preamp. Speaker cables included JPS Ultraconductors, Synergistic Reference 10’s and of course the Lowe’s BFS special; interconnects were RWA and Silver Sonic Air Matrix. No power conditioning was employed.

In case you’ve forgotten, the Bryston B-60 is a little gem of an integrated that’s rated at 60wpc into 8? and 100wpc into 4?. The remote control version (B-60R) retailed for around $1800 for many years, and has since been updated to the B-60 SST. I don’t have any experience with the new model, but it appears to be modestly updated, mostly on the cosmetic front, and hopefully sounds just as good. Given their stellar reputation and 20-year factory warranty, used B-60’s still command very high resale value… something that can’t be said of 99% of the flavor-of-the-month gear out there. The B-60 was meant to last, and so it has, admirably.

This isn’t meant to be a full re-review of the Bryston, just something to facilitate comparison with the current crop of newcomers. So I won’t belabor the specs or construction details. I’ll get straight to…

The Sound. Upon hooking it up, I immediately realized I had sold the old-timer short: this is still a great-sounding amp by most any measure. Next to the laser-like Edge G6 or some of the other integrateds, it’s not necessarily the most transparent or detailed, but it has a very special way of carrying you away with the pulse and emotion of the music. My fiancée, who I admit might have even sharper ears than mine, succinctly commented: "I like the way it sounds, I don’t know why… it carries the melody better, and I hear the phrasing a lot." I had to agree; it’s rich and tuneful in a way which none of the other amps, even the separates, can quite imitate. All these years later, the Bryston still sets an exalted standard of musicality. So, how will the newcomers measure up?

Dussun DS-99 - 100wpc into 8 ohms; 150wpc into 4 • THD: 0.08% @ 90W • 17" x 4.1" x 14", 22lbs; $500 • Imported by AAA Audio, LLC • 617-614-0562 • www.aaa-audio.com

The DS99 was the easily overlooked entry-level sibling of the big Dussun V6i and V8i integrateds that so impressed Rich Weiner in the last issue. At $500 it is by far the cheapest and simplest in this survey. The steel chassis is basic but sturdy, the aluminum front pane is adorned only with a large volume knob, buttons for power and input selection and a headphone jack. There is no provision for remote control.

The review unit was sourced from the amiable and gracious Ping Gong of AAA Audio, Dussun’s only factory-authorized distributor in North America. As with a lot of Chinese gear, a Google search will yield numerous outlets selling the DS99 at wildly varying prices. These gray market goods have no guarantee of being authentic Dussun products and carry no factory warranty. The biggest concern with such a product is the use of a cut-rate power transformer or converter to make the amps suitable for the 120V US market. My advice is to steer clear of such questionable sources. You get what you pay for.

Under the hood. Each of the five line-level inputs is switched using relays, a nice touch at the price point. The selected input is routed to a Alps "blue velvet" volume pot, then directly to the amplifier section - there is no active preamplifier section or preamp output, ruling out bi-amping or directly connecting active subwoofers. The amp section is a DC-coupled design with differential JFET input stage and a complementary bipolar output stage. Choice parts include polypropylene film caps, low-noise Toshiba JFETs and two pairs of Sanken output transistors per channel. I did not get a chance to measure bias current in the output stage, but the DS99 does not employ the "Hyper Class A" adaptive biasing scheme of its big brothers. The unit runs fairly warm at idle, suggesting a fairly typical Class AB setup juiced just enough to get a little Class A power at low levels. (Dussun pictured above)

Small inductors are placed near the output devices, indicating the use of a Zobel network – generally a good thing in my opinion, and something Bryston also puts in the B-60. Time-delay relays keep any pops and clicks from reaching your speakers, and the unit was perfectly silent at turn-on and turn-off – bravo. A beefy toroidal transformer feeds 32,800uF of supply capacitance. Circuit layout is clean and parts quality is excellent for the money, giving no obvious indication of cut corners despite the low asking price. From the no-nonsense chassis to the efficiently executed internals, the Dussun is all business and clearly focused on the goal at hand – no-frills music reproduction.

The Setup. A number of power cords were tried, but the Dussun wasn’t very picky. Try any decently heavy cord with good quality connectors (e.g. 14-3 with Marinco plugs) before going too nuts. Interconnects are a different matter – the Dussun proved itself more than transparent enough to reveal the superiority of the BFS-reference RWA interconnects over lesser wires, so use the best you can afford. Of the two speakers I had in house, the Silverline Preludes were a very nice match in both sound quality and budget level. The unit sent to me had been previously used, so I can’t comment on break-in time, but as with most any amp the sound continues to open up over the long haul.

The Sound. This amp is the real deal. 500 clams does not buy you an Edge or Pass killer, but it does handily cleanse your palate of the bitter taste left by mediocre mid-fi amps of the past. The Dussun’s most salient character is an open, lively quality in the midrange, with excellent detail and articulation. Rich Weiner referred to it as "fast and lithe," and I couldn’t agree more. The midrange is where most of the music is, and the Dussun is an excellent communicator in that area.

The frequency extremes complement the midrange well, if not to quite the same high standard. The treble is nicely extended, with perhaps just a tinge of brightness. Nothing major mind you; when listening to Thomas Zehetmair’s superb rendition of the Mozart violin concertos (Philharmonia Orchestra/Teldec) there’s just a bit more "steel" to his E string than is natural. The foundation of the music in the lower midrange and bass was generally good; it’s not what I would call rich, but not threadbare either. To a greater degree than the other amps, the fleshiness of the sound will depend on the specific synergy with the speaker system and setup. With the Silverline Preludes, I found that switching from JPS Ultraconductor bi-wires to the Lowe’s BFS special helped to firm things up in the bass while opening up the midrange further. It’s difficult for me to comment on the lowest reaches of the bass without having a true full-range speaker on hand, but I did get the opportunity to hear the Dussun with a pair of large Focus Audio speakers in someone else’s home, and came away very impressed with the extension and control in the bottom octaves.

Power is ample; not a hint of murkiness or obscurity of the kind one often gets with mid-fi solid state amps with triple-digit power ratings. It’s not a dynamic beast, but it has a sense of ease and control that could easily be mistaken for a high-end 150 wpc amp. Sometimes amps can be powerful in absolute terms, yet give you the impression that they’re a little twitchy or on edge. The Dussun sounds fundamentally stable and easily handled any sane listening level in my apartment. What it doesn’t do as well as the more expensive reference separates is capture the subtle dynamic pulsations, inflections and micro-explosions in the music; compared to the ME or Edge, it’s a tad flat and not as expressive.

Nits are relatively minor, and I suspect that the ones I heard related in large part to the passive nature of the Dussun’s preamp section. The soundstage is nicely focused but a bit narrow, particularly when the volume control is at a low position. It doesn’t have the width and space of the separates, nor the lateral placement and spread of the Stello. Adding the MSB preamp and cranking the Dussun’s volume to the max (essentially making it a regular amp) resulted in a more open and detailed sound with a much better sense of stage width; thus confirming my suspicions. The upper midrange has a bit of grain and roughness compared to the ME or Edge, but then those are two of the smoother, more grain-free solid state amps I’ve heard. All in all, when one considers the mass-fi price of the Dussun vs. the decidedly excellent sound quality, one can’t find a whole lot to bemoan.

Listening to Saint-Saens Cello Concerto (Pieter Wispelwey, Channel Classics SACD), the tables turn a bit… the orchestral accompaniment which sounds a little muddy on the Bryston comes through clearer and more incisively on the Dussun. The Dussun is also slightly more detailed, revealing a bit more ambient glow around instruments. Wispelwey’s performance of the Frank Sonata transcribed for cello exhibits greater clarity with the Dussun, the piano opening sounding a bit less muddy and the cello’s lower registers coming across more distinctly from the piano’s. The bottom end of the cello also sounds a tad deeper, more articulate and more controlled, though the Bryston has a bit more warmth on the cello’s D string.

An interesting experiment was using the Dussun as an amp with the Bryston’s preamp section; the sound took on a lot of the quality of the Bryston, including some of the negatives like the loss of specificity at the back of stage, yet retained the cooler, more even character of the Dussun. Regardless, the Dussun on its own is a very fine performer that, while not quite trumping the venerable Bryston, it certainly gives it a run for its money.

April Music Stello AI320 - 140wpc into 8 ohms • THD: 0.005% @ 30W • 17" x 4.1" x 16.4", 27 lbs. MSRP $2,795 • April Music • www.aprilmusic.com

The Stello is the priciest piece in this survey, and it shows from the moment you unpack it. The brushed-aluminum chassis is classy and upscale, the neatly organized back panel revealing numerous connection options of obvious quality. The front panel has a series of stylish round buttons for the various functions and an electronic display that shows the selected input and volume level when the unit is on (or superfluously reads "STANDBY" when it’s off). In addition to four line-level RCA inputs, there’s a pair of balanced XLR inputs and a "bypass" RCA input that feeds the amplifier section directly – perfect for hooking up a separate surround sound processor in a double-duty audio/home-theater rig. RCA preamp outputs are available, and the insulated binding posts are excellent. Unlike so many posts I come across that are too chunky for 1/4" spades, the posts themselves are rectangular cut; so smaller spades will fit one way while larger ones will fit the other. The plastic knobs are easy to grip and tighten down, and the banana jacks have a nice snug fit. If only all binding posts worked this well.

All functions can be controlled via the extruded aluminum remote control, which also controls the companion CD player in the Stello line. I never cared for the Krell-style solid metal remotes that are so fashionable in the high-end – they’re heavy and awkward, can damage coffee tables and usually have poor ergonomics. Nevertheless the remote worked fine and includes a handy dimmer switch for the front-panel display. I liked the operation of the electronic volume control, which was plenty fine enough (0.5dB) yet easy to adjust quickly, and also memorized its setting for each input source. In every aspect of its operation the Stello was smooth and a pleasure to use.

Under the hood. Popping the top reveals the Stello’s beauty to be more than skin-deep. All input jacks are directly connected to a multi-layer PCB that neatly holds all preamp and power supply circuitry. A completely separate circuit board mounted behind the front panel keeps all noisy control and display circuitry well removed from the audio circuits. The relay-selected inputs are routed to a discrete transistor buffer stage with dual-differential JFET inputs, indicating a truly balanced input circuit. A Cirrus (Crystal) CS3310 IC handles electronic volume control and drives the amplifier section directly. Despite the manual claiming a DC coupled signal path, I found a 10uF film cap at the input to the amp section. The preamp and tape outputs are buffered by OPA2604 IC op-amps; note that these are only in the signal path for the external RCA outputs. Like the Dussun, the amp section is a classic JFET input/bipolar output affair, though in this case the two pairs of output devices per channel are newer Sanken devices that incorporate multiple parallel transistors into a single large package. These relatively expensive devices are known for their excellent bandwidth and power handling, and are mounted on appropriately beefy heatsinks. Muting relays protect the speakers from unpleasant hiccups during operation. Powering all this is an impressive fully shielded 800VA toroidal transformer feeding a 90,000uF capacitor bank for the amp and another 23,000uF for the preamp. The amp runs warm at idle and could get toasty in operation, but never burning hot. The IEC power input module appears to include AC line filtering. Parts quality and build quality are top-notch.

The Setup. This amp deserves better than the stock 18-3 cord, and the always-reliable Audience PowerChord proved up to the task. The Silverline Prelude was used for the majority of listening (as is typical with most solid state amps, the Merlin TSM’s were not a good match). Other than that, the Stello was pretty much as plug-and-play as they get. Though I had a balanced CD player on hand (the Stello CDA320), I did not have a chance to test the XLR input, which is unfortunate –unlike so many XLR connections that are not fully differential or use IC op-amps to convert to and from single-ended, both the CD player and integrated implement truly balanced discrete circuits. As with the Dussun, the review unit was previously used, so break-in time could not be ascertained.

The Sound. Of all the amps in the survey, the Stello had the least personality. That’s meant neither as an indictment nor a commendation per se; but at the end of the day, that’s just how it came across. Tonally it’s well fleshed-out, with more weight than the Dussun and bit more lower-midrange heft than the MSB/ME or MSB/Edge combos, but less warmth than the Bryston. It’s also a tad less bright than the Dussun, with a less prominent upper midrange, though there was still some steeliness to Zehetmair’s E string in the Mozart concertos. At the same time, it has a slightly "flatter" quality than either the lithe Dussun, the lively Bryston or the more transparent separates… there’s nothing unduly electronic or artificial about it, it just comes across as a bit more reticent than the others.

Detail-wise it does a good job of capturing the general ambience of a concert hall, if not the "air" of each individual instrument - the varying ambient colors from different sections of an orchestral stage sound a little homogenized. Dynamics have a similar quality, with subtle inflections being glossed over; in musical terms, there’s a sort of mezzo-forte and sostenuto quality to the sound which makes things sound a little uniform vs. the more varied dynamic palette of the reference separates. Normally these are things MGD and I would ascribe to the sound of IC op-amps… in this case, the culprit could very well be the Crystal volume control IC, which has internal op-amps. To test this theory, I tried using the "direct" amp input on the Stello with the MSB preamp. The result was a lighter, more open and detailed sound, with a sense of agility and clarity missing when using the internal preamp. The downside was that it was tonally a bit too light, and in the end I found the internal preamp to be a better match overall.

In fairness, I might be erring on the overly critical side, because this is good-sounding amp with plenty of clean power. Britten Suites for solo cello (Wispelwey, Channel Classics) sounded remarkably life-like on the Silverline Preludes, the cello having spot-on tone quality and a perfect balance of body and texture. Of all the integrateds, the Stello sounded the most open and at ease when playing the Britten at realistic volume levels; in this respect it was very much a match for the reference separates.

Head-to-Head with the Bryston. Switching from the Stello to the Bryston immediately reveals the latter’s superb tactile qualities and richness of images. The Stello has a dryer midrange that’s just a hair tizzy in the transition area to the treble. Images in center stage are a tad defuse; listening to Wispelwey’s Frank Sonata, piano and cello seem a bit unfocused. On the plus side, its lower midrange is less congested than the Bryston’s, and its presentation will appeal to those who prefer a bit more delicacy and subtlety. With more than double the power, it also possesses far more dynamic headroom. Though the Bryston is good for all of its rated 60 watts (and maybe more), the beefier power supply and output section of the Stello will keep on cranking long after Bryston has run out of steam. At the same time, the Stello has a more subdued sense of rhythm, and comes across less vibrant and alive than the Bryston. Still, there will no doubt be those who prefer the Stello’s even-keeled demeanor and ample power.

Looking more like a car stereo amp than a home hi-fi component, the NuForce is the lone Class D amp of the bunch, and also the quirkiest. Perusing the manual reveals numerous ominous warnings. "WARNING! Do not connect NuForce outputs to the line-level inputs of active devices such as active subwoofers…" "WARNING! Use only grounded AC power cords." "Always immediately disconnect the power to the equipment in the event the devices emits an unusual odor or sound or generates smoke." Yikes… sounds more like one of my hacked-together DIY projects than a mature consumer product. As is common with many switching amps, the speaker outputs are not referenced to ground and can become unstable with no load, so much care must be exercised during setup. During everyday use a lot of clicks and pops can be heard through the speakers, further reinforcing the dread of a catastrophic explosion or similar audio meltdown. In contrast to the elegant and refined Stello, the NuForce was less than confidence-inspiring in its operation.

The back panel has two pairs of RCA inputs and two stereo mini-plug inputs for iPods or what not, along with a pair of preamp outputs. A "booster" switch allows one to turn off the amplifier section. The insulated binding posts are par for the course and necessary to meet EU safety regulations. The front panel has two knobs which electronically control input and volume. Pressing in the input knob turns the unit on and off, while pressing the volume knob activates the mute function. The volume control was a nightmare to use – each detent of the knob makes an absolutely infinitesimal change in volume level, thus requiring many turns to effect any major change in level. The small full-function remote control had the same issue; one needs to hold down the volume control buttons for what seems like an eternity before the volume level changes significantly. Even with my best video game button-mashing technique I would still find myself pumping the button endlessly. This is something that definitely needs to be fixed in firmware.

So how does it work? First, a little primer on "Class D" switching amplifiers. A traditional linear amplifier, usually of the Class A or Class AB variety, attempts to preserve the signal in its original form from input to output, only higher in power level – the "straight wire with gain" concept. In contrast, Class D amplifiers generate a high power pulse signal at a frequency many times the intended bandwidth (usually at least a couple hundred kilohertz.) and modulate it with the input signal in a technique called pulse width modulation (PWM). By passing that modulated pulse through a low-pass filter, the original waveform is magically reconstructed.

Okay, that doesn’t sound very intuitive, so let me present a rough analogy. Let’s say you’re trying to drive a car on the highway. A linear amplifier would be akin to the way we normally drive – the car has an infinitely adjustable throttle control in the form of a gas pedal, and you put your foot on it a certain amount to get to the desired speed. You adjust your foot pressure based on what the speedometer says in a form of negative feedback – just like in an amplifier. A Class D amp on the other hand would be like a car that had only an on-off throttle switch in place of the gas pedal, and some kid on ten shots of espresso at the wheel. Since the kid can’t fine-tune the throttle, he has to selectively pump the throttle switch between on and off, watching the speedometer to tell if he’s under or over the desired speed. How in the world will he ever maintain a steady 55 mph? Well, the car has inertia – turn on the throttle, and it takes time for the car to reach top speed; turn off the throttle and the car gradually cruises to a stop. This is the function of the low-pass filter in a Class D amplifier; it creates "inertia" in the signal and integrates the high-speed pulses into a relatively smooth output. In this fashion and with some skill (a high-enough switching speed and conscientious speedometer reading), one can actually control the speed of the car with great precision.

This is basically how PWM works, and it’s employed in everything from Class D amps to 1-bit D/A converters to the motorized arm of the robot that welded the door of your Ford Explorer together. But I digress... why exactly would one bother with this convoluted amplification scheme? Because transistors are intrinsically non-linear devices that are more efficient when used as on/off switches rather than linear amplifiers. Class D amps that also employ switching power supplies often boast power efficiency ratings of 80% or higher; compare that to the typical Class A brutes that MGD so loves, which are constantly burning off hundreds of watts of heat even when delivering just fractions of a watt to the speakers. Class D’s efficiency gives it obvious cost, size and weight benefits.

A common misconception is that the "D" in Class D means "digital," thus implying some sort of conversion of the input signal to the digital domain. This is only true of Class D designs that employ a digital pulse modulator, such as TI’s "PurePath" technology commonly used in home theater receivers. The analog approach preferred in audiophile circles is to use an oscillator as the pulse source, modulated with an appropriate comparator circuit and with negative feedback applied to smooth out frequency response errors and distortion. Class D implementations that fall into this category include the NuForce, analog ICEPower modules from B&O and the Hypex UcD modules. Tripath’s "Class T" chips popularized by the $30 Sonic Frontier T-amp are a bit of a hybrid, using both analog and digital signal processing techniques to generate a spread-spectrum pulse modulation.

A big problem with Class D is radiated high frequency noise. Because of the output transistors rapidly switching at full power, the entire amplifier can become an RFI nightmare, spewing all kinds of nasty harmonics into the gigahertz range. Another challenge is ensuring linearity and flat frequency response into the complex load presented by a typical speaker. Fine-tuning the modulation scheme, low-pass reconstruction filter and feedback loop into a single stable, linear and consistent system is a challenge, and as with any technology that hasn’t fully matured, designers are still learning the art of making it all sound good. Early examples of Class D were pretty hard on the ears and relegated to car stereos and active subwoofers, but the technology has clearly made large strides towards audiophile legitimacy in the last several years… whether it’s truly ready to challenge the finest traditional amps is still questionable, but just as with digital audio in the 90’s, Class D is rapidly gaining ground.

Under the hood. Unlike many companies which repackage existing Class D solutions, NuForce employs their own fully-analog implementation. The slim extruded aluminum chassis is absolutely jam-packed with circuitry, most of it looking nothing like your typical audio component. The preamp section uses the ubiquitous NE5532 op-amp in surface-mount form. (Before you write off the much-maligned ‘5532, keep in mind it is still used extensively in some pretty good-sounding products like the Benchmark DAC-1.) The 16-pin volume control IC has been stripped of its part number and covered with a NuForce sticker; my best guess is a Burr-Brown PGA2311 or similar part. The preamp is connected to the amp module using several inches of spaghetti-thick coax wire. The amp front-end also uses NE5532 op-amps, along with LM319 comparators and a Xilinx FPGA. The output stage uses a Harris HIP4081 FET driver IC operating off a single supply and feeding four small power MOSFETs in a full bridged (push-pull) configuration. Both speaker terminals are actively driven and floated at half the supply voltage (24V), so one must be careful not to connect either of them to ground in any way. The output filter consists of numerous toroidal inductors and capacitors, including some large NuForce-branded electrolytics. An additional common-mode inductor and film cap are placed at the speaker terminals to further filter HF noise. The power supply appears to be an off-the-shelf switching supply rated at 100 watts; it’s about the size of a cassette tape (remember those?) and outputs a single +48VDC rail which NuForce stiffens with an additional 24,000uF of capacitance. An even tinier auxiliary switching supply powers the control circuitry.

Each amp comes with a printout of actual bench measurements such as THD, S/N and frequency response for that particular unit. Component quality is generally okay, though there are some ho-hum touches like the cheap coaxial wire connecting the preamp to the amp. The small power supply (even by switching standards) is also cause for concern, but one must take into account the cost of engineering and manufacturing a proprietary implementation versus simply repackaging an off-the-shelf solution like ICEPower or Tripath.

There have been reports of NuForce amplifiers generating substantial RFI to the point of interfering with ancillary audio gear and nearby electronic devices. I was unable to set up a measurement rig to test this in time for this review, but it’s something I’ll need to investigate with Class D amps in future installments.

The Setup. The NuForce comes with a decent 16-3 cord with an attached ferrite bead. Normally I’m not a big fan of ferrites, but in this case it’s probably necessary to keep the NuForce from spewing too much RFI junk back into your power lines. Switching to the Audience PowerChord lifted some of the deadness I attributed in part to the ferrite, but also introduced a bit of grain and hash and thinned out the lower midrange. Also remember that the floating ground cords some audiophiles use are a no-no. I wound up sticking to the stock cord for the majority of my listening.

The entire chassis runs quite warm to the touch at idle but doesn’t get too much hotter when you crank up the volume – that’s Class D power efficiency for you. The review unit was factory-fresh and spent a lot of time on the burn-in rack continuously playing MP3s at high power levels into 4? dummy loads. Break-in time was an eternity… after a few hundred hours I’m still not convinced it’s really settled down. For some reason modern audio electronics like CD players and switching amps seem to require an incredible amount of break-in to really loosen up… perhaps it’s the lower power dissipation of the circuits, or the high speed of operation. Whatever it is, I would recommend at least 100 hours playing time before doing any serious listening.

The Sound. Before the aforementioned burn-in period, the NuForce sounds bad, really bad, and the first few dozen hours of burn-in seem to do little good. I’m sure there must be at least a few NuForce owners out there who experienced a week or two of disenchantment immediately following their purchase. With patience however, the NuForce develops into a formidable amp in two areas: bass and midrange articulation.

With a claimed damping factor of 4000 and the efficiency of Class D, you’d expect the NuForce to exhibit excellent dynamics and grip in the low end, which it does. What caught me by surprise, however, was the balance and transparency throughout the bass and lower midrange. Listening to the Scherzo movement from Mahler 5, bass and trombones have well-centered pitch and timbre throughout their range; there’s weight without heaviness, definition without dryness. Bass drum has an uncanny steadiness of timbre from impact to decay… it’s a unique sensation that’s difficult to describe, but once you hear it, other amps sound slightly lumpy and clouded in comparison. What I suspect I’m hearing is not necessarily the superiority of Class D at low frequencies (though that could also be a factor), but the absence of low-frequency coloration by using a switching power supply. Traditional linear power supplies rectify the incoming 60Hz AC and attempt to smooth it out using large capacitors and sometimes active regulation, but even with such measures there are lingering issues of ripple currents, varying source impedance and distortion. With a switching supply, the issues are pushed much higher in frequency, usually above 10kHz, and for good measure NuForce has augmented the supply with fairly large storage caps to ensure ample current reserves. When used with the Silverline Preludes, one couldn’t help doing a double-take at the quality, control and extension of the bass from such a small speaker and amp.

The good news continues in the midrange, which manages to be silky-smooth and detailed in a way I’ve found typical of the better switching amps, but with a surprising degree of warmth and fullness. Going back to the Scherzo movement of Mahler 5, midrange resolution was striking; the back-and-forth repartee of thematic fragments played by different sections of the orchestra came across with articulation and clarity, allowing one to make out the complex score with ease. On the other end of the musical spectrum, the midrange resolution brought alive all sorts of little inflections and details in tracks from Red Hot Chili Peppers One Hot Minute.

Spoiling this a tad is a mild case of opaqueness and thickness in the midrange, something I’ve heard from the ‘5532 op-amp before. But above the midrange, we start to see more serious transgressions. Out of the box the treble has a tingy, unnatural quality that mostly burns off, but never quite disappears. There’s a lingering grit to the upper harmonics of string instruments and a brittleness to brass instruments. Musical passages with a lot of sustained high-frequency energy can take on a "white noise" quality. At the same time, the upper midrange errs on the soft and recessed side, with a clear loss of resolution with increasing frequency. It’s akin to the fidelity loss one often hears with IC op-amps, but more severe... I suspect it could be coloration and signal loss from the fairly extensive but necessary filtering employed in the amp’s output stage.

At times there’s also an odd coloration that I can only describe as a "whooshing," like some sort of weird high-frequency Doppler distortion. The issue is in the top two octaves, and depending on your HF sensitivity it could range from mildly observable to maddeningly annoying. I found that I was able to adjust to it to a degree, but switching back and forth with the other amps would immediately put the spotlight back on the problem. My more sensitive fiancée could never quite put her finger on what was bothering her, but in the end she found it quite distracting. I’ve heard these kinds of HF aberrations from other Class D amps before, and it’s something you really have to hear for yourself before deciding if it’s acceptable.

Last but not least is a weird "noise gate" effect where the background is artificially black and the tail end of notes die out a little too quickly – something akin to what MGD complained about with SACD reproduction, which interestingly enough is also a PWM-based technology.* This basically decimates subtle ambient cues and low-level information like the air around instruments on the stage, something I refer to as the "glue" of the soundstage. Without this glue, instruments can still image clearly, but they are not held together and related to one another in a singular acoustic space. With solo work like the Britten cello suites, the sense of hall space was mostly obliterated, and the instrument lost much of its silky sheen and treble texture. Some of this is due to the softness of the upper midrange, which can be balanced with the right speaker; the more forward Merlin TSM was actually a good tonal match and minimized the loss of texture, but also further revealed the other low-level resolution issues.

Individually these issues aren’t necessarily deal-breakers, but in combination they give the sound a synthetic feeling, as if you’re listening to a re-enactment of the original musical performance rather than a reproduction. It’s odd because in some ways the NuForce is extremely detailed and musical; in others, it sounds very electronic. To a purist ‘phile bent on capturing the closest facsimile of the original event, its faults will no doubt seem wholly unacceptable. Yet I can’t help wondering if there are some music lovers out there for whom the articulation of individual voices and the solidity of the music’s foundation are more important, and the other issues are less critical to their enjoyment of the music. More so than any of the others in the survey, the NuForce is an amp that will evoke strongly varying reactions from different sets of ears.

Head-to-Head with the Bryston. The Bryston and the NuForce have modest power ratings of 50wpc and 60wpc respectively, but both are dynamic beyond what the numbers would suggest. The Bryston is better able to sustain its power, while the NuForce is a bit more explosive. Both are on the warmish side of neutral, with the Bryston being fuller in the upper bass and more forward in the presence region, while the NuForce is more recessed through the upper midrange. Treble fidelity goes hands down to the Bryston, while bass extension and dynamics go to the NuForce. The Bryston also runs out of steam more gracefully than the NuForce, which sounds very harsh at its limit most likely due to the small power supply pooping out at 100 watts. The NuForce is able to better distinguish individual images, but overall soundstaging goes easily to the Bryston, which just sounds hands-down more natural than the NuForce. With the Mahler 5 recording, the NuForce articulates the different voices more clearly, but in the end the Bryston paints a more cohesive and convincing "big picture."

For an urban ‘phile like myself where time, money and space are all at a premium, integrated amps make obvious sense. One less power cord, one less pair of interconnects, one less spot on the audio rack… the convenience afforded is compelling to the point where I’d be willing to make some sacrifices in sound quality. Thankfully, with this bunch, I never felt sonically compromised for having taken the easy way out; in fact, in terms of sound quality for the money one would have a pretty hard time finding separates combos on a comparable level.

The Dussun proved itself to be a real audiophile’s amp, with a combination of neutrality, detail and musicality that amps costing 3-4 times as much would do well to imitate. Even if it cost double what it did I’d consider it a solid value; at $500, it’s an unqualified steal. If you’re on a tight budget, or simply looking for a great amp that doesn’t cost a fortune – heck, even if you’re prepared to spend hundreds more – definitely give the Dussun a listen.

The NuForce is the most idiosyncratic of the bunch, and the hardest to recommend. Its bass response and midrange articulation are exceptional, while the forgiving upper midrange helps balance more forward ancillary gear. When used with the right speaker, its strengths will clearly appeal to some music lovers; to others, its treble fidelity and low-level resolution issues will compromise the credibility of the reproduced event. Ultimately my feeling was that it has some kinks to work out and isn’t quite ready for prime time, but based on my experience with it I can say that Class D has great potential and will continue to gain followers. If you have the opportunity, the NuForce is at least worth a serious listen with an open mind.

So where does this leave the venerable Bryston? Each of the contenders was able to equal or surpass it in at least a couple areas, the Dussun in particular being musically competitive at a fraction of the price. But after dozens of hours of listening and countless A-B tests, there was always something special about coming back to the Bryston... I can’t say it any better than MGD, who a decade ago described it as a "warm audio nest. " It had the sweetest and most natural treble reproduction of any of them, and was the run-away winner in musical involvement. If the newest "SST" model is upgraded in performance without losing any of the "magic," I have a feeling it will easily defend the B-60’s title as a BFS reference.

Modern power amplifier technology seems to be going toward smaller, cooler, cheaper. More digital amps, switching amps, class D amps, class LMNOP amps, and fit in your back pocket amps are being introduced each and every month. These are the things that supposedly drive the amplification industry today. That being where the excitement is, why is it that whenever a person enters the BFS World Headquarters and sees the Pass X350.5 sitting in the Big Rig, it's the Pass they ask questions about? Things like: How many wpc?; What's it cost?; Does it weigh a lot?; Do you like it?; Can I hear the Pass amp first?

And after they hear the Pass X350.5, the comments are generally along the lines of: "That thing sounds awesome!; I'm a tube guy, but I could take that amp home; I've never heard an amp that powerful sound so good; When you're done with it can I have it? Are you going to keep it?" Other amps don't get the same response. Even the PBN Sierra Olympus, a real looker, could not garner the ooohs and ahhhhs the big Pass does.

Having reviewed the original X350 in issue #160, I was fully aware of the physical presence possessed by the Pass. Merely having it in the system captures the attention of most onlookers, even those here for reasons other than audio. Not since the my Maggie MG3A's were mistaken for room dividers by a friend of my wife, has a product been so commented on by persons alien to audio. But its looks could not snare a positive review from BFS the first time out and the old amp left me lukewarm sonically.

Quite frankly, I was surprised by Joe Sammut's positive response when I requested the "improved" version of the amp, now called the X350.5.¹ The .5 designation has been given to the newest amps in the X division of the Pass corporation, it representing significant upgrades to the original design. In spite of loving the X250 as reviewed in issue #150, I felt no special affection for the X350, noting that the X250 ($6,000) was the superior sounding of the two. Most manufacturers consider a single negative comment like that the "kiss of death" for future reporting ... after that they promise gear, but it never shows up. Pass isn't like that, and for that reason (amongst others) I have great respect for the individuals representing the corporation as well as the corporation itself.

What it means to be an X.5 amp. You could call it a child of trickle down technology. An exceptional amount of time and effort went into the development of the XA line of power amplifiers. The XA amps are single ended, high current, hot running, technological front runners that stretch the concept of purity to a whole new level. To create the XA amps (a merging of conceptual designs derived from the Aleph amps and the original X line), new approaches to old problems had to be developed. It was then realized that many of the design developments meant for the XA line could be incorporated into the original X line with minimum expenditure, hence the modest increase of $500 from the X to the X.5.

The mechanical changes made to the amplifier include improved transformer design; paralleled high speed, soft recovery rectifiers; improved AC line filters; increased paralleled power supply capacitance; increased RC filtering, and; refined class A input circuits taken directly from the XA series of amps. In essence, what Pass has done is incorporate much of the XA input section and blend it with improvements to the existing power supply. The result being a stereo amplifier of staggering power capabilities with improved and refined sonics. Oh, and it runs hot. One doesn't get as much class A power as this amp exhibits without burning some wall power.

What's inside. The X350.5 is a stereo amplifier accepting balanced as well as single ended inputs. Damping factor is 250. Power is rated at 350 wpc into 8 Ohms, 700 into 4 Ohms (class A to approx. 65 wpc). Gain is 30 dB. Input impedance, 22 kOhm balanced and 10 kOhm unbalanced. 600 watts draw at idle up to 1,800 at full draw. MOSFET output section (24 devices per channel). I.8 kVA toroid transformer. Frequency response is DC to 100 kHz at -3 dB. 11.5" x 19" x 22" (HxWxD), and the unit weighs 150 lbs.

Set-up. The low input impedance for single ended operation (RCA) is the major consideration when putting a system together around the X350.5. 10,000 Ohms is a nasty load for a tube preamp to drive. The Monarchy Model 24 preamp section sounded okay with the Pass, but much better with amps having impedances in the 100,000 Ohm range. The ModWright SWL 9.0 SE tube preamp came in recently, and the first thing I did was hook it up to the Pass. They didn't play well together, not a good combination. On the other hand, the combination of the Pass with the solid state Symfonia Opus 8 preamp was a very special duo that I'm having a hard time pulling out of the Big Rig. Therefore, using a tube preamp with this amp is questionable. Using a good solid state unit is a sure bet.

My set-up included a base made up of two butcher blocks, one stacked upon the other. Why two? Primarily because I have two, and if the Pass had been a mono block as was the XLH, each amp would have been used with one block. I don't think there is any special magic in using two blocks. They just take up less space this way. I have received several inquiries regarding the necessity of using brass cones under the butcher blocks for coupling purposes. Use any kind of cone you want. Don't fret over it being brass, aluminum or anodized elephant snot; they'll all work.

Interconnects used were from RWA. I still haven't found anything better. The power cord situation was a little different. The X350.5 was actually pretty immune to sonic fluctuations due to using different power cords. The Audience PowerChord provided a warm and energetic field. The homemade Lowe's 6 awg also sounded very good, it being a little faster sounding than the Audience, but less tuneful. Being the audio glutton that I am, I must report that one power cord sounded the best with the Pass amp - the JPS Aluminata. At $4,500 for two meters of super heavy AC snake, I cringe as I type these words understanding the revelry and joy I took in presenting the "uber" values in issue #171. But, I must report that the X350.5, in combination with the Aluminata, resulted in superior performance in every respect. And I've wrestled with the propriety of reporting on a product using a power cord that costs more than most people's entire system. It's not realistic to assume that everyone buying a particular product will spend $4,500 on a power cord. Of course, that varies depending on the price of the component being reviewed. If it is a $1,500 CD player being covered; not likely. On the other hand, a guy buying a $17,000 Reimyo or a $39,000 Boulder 2010 phono section may not think twice about using a power cord costing as much as the Aluminata. Fortunately, the JPS enhanced the performance of the Pass more than it transformed it. And so it has been with other components that I've had the opportunity to use the JPS with. Use of the JPS does not so much make a component become something else; rather, it optimizes the operation of a product, creating an optimal electrical environment to perform in. In the case of the Pass, it sounded better to me with the JPS than it did with other cords. However, the basic character of the amplifier remained intact regardless of the cord used. It is that basic character that I will be reporting on. And if you don't want the Aluminata, buy the Audience.

A note on break-in. The old 350 always seemed like it was just a day from breaking in. Unfortunately, that day never came. And if you left the amp off for a while, things got worse. Out of the box, the 350.5 took just a few days to get right, and even when it is off for a day or two it comes back to optimum performance in less than an hour.

Degree of transparency. This amp sounds nothing like the 350 reviewed back in November of 2004. It's better now, and better in almost every conceivable way. This is the performance that I expected with the original 350 and then some.

Even a very good MOSFET solid state amp, such as the 350.5, does not sound like a tube amp, nor does it sound like a tube/solid state hybrid amp. The 350.5 sounds dryer than the Moscode HR401 and the Monarchy SE250. Or you can say that the latter two amps sound wetter than the 350.5. It's a sonic quality that I believe has everything to do with the use of tubes or solid state devices; not in the output stages, but in the low level voltage stages. Quite frankly, I appreciate both approaches to sound, recognizing that each has something special to say about a musical performance. What I hear with the 350.5 is what I called an "attractive dryness" after auditioning the Ayre V-5x at the CES two years ago. As I said in the CES report, I liked the way the Ayre sounded and I tossed some substantial compliments in its direction. The Pass is similar in that it too lacks the glassiness in the upper mids that so many amps try to pass off as upper midrange articulation. It sounds as if some odd order harmonics have been eliminated, leaving a drier but more listenable sound. Substance is the result. I find this particular sonic quality of the Pass, and the Ayre for that matter, difficult to describe. The words necessary to describe this quality, "attractive dryness," are the words generally used to illustrate a negative sonic quality. Yet this amp, by not over emphasizing certain elements of the sound comes off as less wet, but more textured and substantial. This is definitely a case where, to my ears, less is more.

The stage perspective taken by the Pass 350.5 is between up front and mid hall. By no means is it distant in any way. When listening to the Pass the user listens into the event rather than the event coming out to include him or her. It's a way of describing one of the basic sonic differences between a tube hybrid and a solid state design. Sitting in the sweet spot with the 350.5 treats one to a stage with excellent spatial cues and natural locations. The amp is exceptional in that way. The Pass' aura (air) is clean and sweet to the back of the stage. It is dynamic and alive, but it keeps its images just behind the front face of the speakers; therein (I believe) lies the reason for the slightly closer than mid-hall perspective. When put in a regular hi-fi system, the Pass will sound more up-front than other solid state amps (the vibrancy); though it will sound less forward than tube amps and hybrids. That's why this amp, in comparison to the hybrids, comes off as less wet, less splashy, and perhaps more in control. Control, however, will be the last thing you'll be thinking about when you listen to ZZ Top's Tres Hombres. "La Grange" is a sure ticket to an air guitar contest when the curtains are shut, and the rest of the family are out.

This a low feedback design and the feedback used is employed in such a way that it has minimal negative impact on the sound. Because this amp uses only minimal feedback as part of the Supersymmetry circuit it doesn't trip over itself when trying to convey dynamic subtleties or depth of stage like high feedback amps do. I also think it is more stable as a result. Negative feedback does not stabilize a circuit. Lower distortion specs may result, but make an amplifier more stable it does not. Anyway, the Pass 350.5 has the bravado, spontaneity and kick that I oftentimes find with low feedback amps, but without the bass bloat that sometimes comes too. Negative feedback destroys contextual music information and low level information.

Speaking of bass and the frequency extremes, the 350.5 is a lesson in accuracy and listenability. This amp delivers extreme performance at the top and bottom, even surpassing the superb highs of the Parasound JC-1, which had been a reference in that regard up to this time. The bass? It's in the same class as the XLH M-2000 ... need I say more? This is the best bass that I've ever heard from a MOSFET amp. In every way it's in the same class as the finest bi-polar amps, and I'm on the record for preferring bi-polars for bass response. Another audio truism bites the dust.

Conclusion. I hope that you haven't tired of reading positive reviews. Like you, I know that not all components are wonderful. But, I have to be honest, guys that make overpriced garbage don't generally want us looking at their equipment. I still feel that the advertising dollar is a means by which some manufacturers purchase insurance against a negative review. I also feel that our backgrounds as hobbyists first, and I'm including our contributors in that wide ranging statement, push us into searching out componentry that we would personally like in our systems. That lone aspect about us as a group means that certain components by certain manufacturers simply aren't going to show up in these pages. For that reason, I've tried to include as writers persons from different viewpoints and opinions. But what we have in common as music lovers is an unswerving dedication to obtaining the finest reproduction of music in the home possible. For that reason, if we come across questionable equipment we relate that to YOU.

In the case of the Pass 350.5 power amplifier, we have an amp that is enormously powerful which to my ears suffers none of the penalties that super power amps are oftentimes stricken with. It sounds like a much smaller amp when it comes to delicacy and resolution of low level information and relationships; an uncommon combination of power with refinement. It's highs are superb. But, when power is required it's available in spades! Earlier in this issue I spoke of the XLH M-2000 having some of the sonic artifacts that come with big power, i.e.; some sluggishness, some hesitancy. There's none of that with the 350.5. The Pass amp is able to turn on a dime and go from 0-60 in the blink of an eye (actually much faster). This is the finest solid state power amplifier that I've had in the Big Rig to date - long live the new king.

Few undertakings during my affiliation with Bound for Sound have been as rewarding or as flat out enjoyable as it was to prepare for, audition and then write about the four moving coil cartridges assessed and compared below. I must acknowledge that part of the pleasure had to do with being able to record my cartridge auditions with the Alesis MasterLink 960 digital burner, then play them back at will. I won’t go into the details of that experience again; it has been well documented in these pages, and our space is limited enough as it is. However, as I indicated two issues ago, being able to record my analog listening sessions with each cartridge onto the hard drive of the Alesis, made, I believe, my observations all the more verifiable, and my conclusions all the more reliable.

I had no horse in this race. I had no reason to desire that one cartridge outperform any other. My sole purpose in doing this comparison was to find, isolate and then accurately describe the sonic qualities of the four best cartridges made in the price range of $1,500 - $3,000. Which is not to say that there are only four good cartridges worthy of consideration within the chosen range of prices. I wanted to include a Benz, a Koetsu, a Lyra and a Van Den Hul, which would have expanded the field and increased the amount of work to be done; but they never arrived. I can understand why the Benz didn’t make it. Musical Surroundings, the importer for Benz and Clearaudio sent the Clearaudio Concerto and probably didn’t want one of their moving coils facing off against another of their moving coils. That’s understandable. Why the importers for Koetsu, Lyra and Van Den Hul not only didn’t send a cartridge, but didn’t respond to my e-mails I have no idea. Are they similarly unresponsive to inquiries from interested buyers? Or were they simply afraid of an honest appraisal?

The moving coil cartridges that I auditioned are as follows (alphabetically): Clearaudio Concerto, $2,500; Dynavector DV XX2 MKII, $1,850; Shelter 7000, $1,995; Transfiguration Phoenix, $2,500.

Every effort was made to create and maintain a level playing field for each cartridge. The details of my efforts to be as fair as possible have been chronicled in issue #187. The goal was to create a comfortable performance environment for each cartridge so that my results would be truly indicative of what one might expect at home. Of course, no one set of components is going to be perfect for every cartridge. But with excellent individual components and an almost fanatical dedication to cartridge alignment and set-up, it was my hope to get to the listening and performance heart of each cartridge and make findings that would test true under similarly meticulous set-up conditions by other audiophiles in a variety of systems. I think I did it.

The following equipment and components were used in this evaluation: Alignment tools included a dB Protractor and an alignment gauge from Clearaudio; an Exact digital down force gauge by Clearaudio; Clearaudio Champion Level 2 table; Origin Live Illustrious arm; Origin Live DC turntable motor; Keith Herron VTPH-2 and Eastern Electric MiniMax outboard phono stages; interconnects by Skywire and RWA.

On the matter of cartridge loading. Correct electrical loading of a cartridge is essential to its optimum performance. Unfortunately, loading a cartridge is not an exact art and the load which seems perfect with cartridge A and phono section B may not be so perfect when phono section C is inserted. It changes. For example, I found out that the optimum load for the Red Rose, Rose Petal cartridge with the Pass Xono was not so optimum when I inserted the Herron phono stage. And the differences were fairly large. In discussing the matter with Mike Pranka of Dynavector, he stated that he believed one could not necessarily predict with any certainty the optimum load for any cartridge, other than high or low (and sometimes not even that). He told me that my test Dynavector would generally sound its best with a low load of around 30 Ohms. But, he also noted that a friend of his had a preamp, phono stage combination that needed 1,000 Ohms to sound best with the same cartridge. That’s a huge difference in my book. Below, I will indicate the load that I found to work best with each cartridge... however, your results may vary.

Again, in alphabetical order:

The lightest cartridge of this group at 4 grams, it also had the longest cantilever and one of the highest outputs (0.7). This unit was unique and extremely easy to align due to the odd way the cantilever juts out of the front of the cartridge body uncovered and unprotected. Yes, it looks like an accident waiting to happen, but it also made alignment within the headshell simple. Most alignment tools have intersecting lines to assist in getting things just right. With a cantilever as exposed as this one was, my view of the alignment lines and the cantilever was completely unobstructed and open to adjustment. Alignment was a breeze.

Due to the extreme light weight of the Concerto, I was concerned that I might not be able to get the standard counterweight on the Illustrious arm to adjust inward far enough to balance the arm without adding weight (and mass) to the headshell. Matters were made potentially worse by the recommended tracking force of 2.8 grams, the highest of any tested. I barely made it… My testing was done at 2.8 grams, but had I needed to go to 2.9 grams, there could have been trouble.

Electrical loading of the Concerto was recommended at 500 - 47,000 Ohms. That was easy enough, but to think that the cartridge would perform equally well under all settings within that range is silly. With the Herron phono stage the "Infinite Load" setting sounded best, and with the MiniMax I liked the Concerto at 47,000 Ohms. As always, your mileage may vary. But beware, in a friend’s system the Concerto sounded goofy good at 100 Ohms and not so hot at 47k… go figure.

Tracking with the Concerto was superb at any force between 2.5 and 2.8 grams. The Illustrious is heavier than many high-end arms at over 14 grams. With the Concerto being a medium to high compliance cartridge (15), I spent a good deal of my set-up time looking for cantilever flex and listening for mistracking. I observed neither (to alarming degrees). And while I cannot say that the Concerto was the absolute best tracker in the survey, it navigated cannon blasts as well as sparkling bells with equal grace. Fact is, unless you have a really junky tonearm, all of these cartridges are going to track everything you put in front of them, good and bad.

The Concerto had the highest output of this group with a standardized output voltage of .7.

Performance. Each of the cartridges auditioned sounded different from the others; that should not surprise. Of these cartridges, my short phrase description of the Concerto would be one word: "Flashy." Of the four pick-ups auditioned, the Concerto from Clearaudio was, to me, the one most likely to make me say "Wow!" Granted, there were times when I would instead say, "What?" But for the most part, this was a cartridge willing to take a chance sonically in an effort to best portray the excitement and illumination of a well performed piece. Along those lines, it has some of that inward illumination most often thought of in association with Audio Research tube preamplifiers… things lit up. It’s not however, the soft glow found with some tube components, nor is it bright. It’s the illumination one hears when the beginning of a plucked transient (a steel guitar string for instance) comes out of nowhere with a sudden start and clean beginning such as that on Stevie Ray Vaughn’s "Tin Pan Alley." It’s the rich and colorful rendition of a full set of complex harmonics that accompany a Hammond B3 organ on Santana’s four channel rendition of "Oye Como Va." It’s the illumination one senses without thinking about it when listening to the audience involvement with Neil Young before "Don’t Let It Bring You Down" on Four Way Street. It allowed me to hear the low level textures and sonic shadings that let the music breathe. This cartridge did the little things that made a recorded performance exciting and capable of transporting the listener back to a reasonable facsimile of what the original may have sounded like. With its speed, dimension and superb low level resolution the Clearaudio projects a real life focus on a performance. The Dynavector and the Shelter did not go there with the eerie reality the Clearaudio was capable of.

Tone quality was very good with this cartridge, and individual instruments had their own spaces and dimension. Pacing was excellent. Left to right placement and movement was precise and fluid. Klaatu’s "Little Neutrino" from their first album was a kaleidoscope of moving colors, buried detail and interstellar bass bombast. From this cut, interestingly enough, one can pick out and isolate two minor drawbacks in the performance of this cartridge. First, in the bass the Concerto goes deep, but not sub-deep. And secondly, with all of the excitement at the front of the stage, depth of stage was in some instances foreshortened.

In the bass department there was abundant low frequency energy when called for, sufficient for the Clearaudio Concerto to move you, though not give you the bass (shake the loose coins in your pockets) quake that the Shelter will. The best thing about the bass to me was the way it carried an ungranulated melody. It was smooth and moving without glossing over. Because of that quality, bass play with this cartridge had a paced, precise and fluid quality that was more prone to carry a melody along as opposed to pounding it into you.

The dreamy stage depths and finely graduated layering of the Transfiguration Phoenix were brought forward somewhat with the Concerto. The Concerto made large live venues seem a little more intimate (smaller) and close by bringing the rear of the stage a smidge forward. The resulting perspective was that images were a little larger, a little more immediate. I observed a similar image perspective shift when auditioning the Eastern Electric M156 mono tube amps, though the Concerto’s magnification wasn’t nearly as dramatic as that of the power amps. And there is this. I reserve the possibility that the Concerto wasn’t bringing things forward, but was instead illuminating the rear of the stage to the point that since things at the rear of the stage are so observable they seemed closer. That’s a possibility, though right now I’m tending toward the first description.

A strength of this design was its ability to retrieve background ambiance and low level information. On many recordings, even low resolution rock and roll recordings, there exists hidden ambiance and room interaction information. Drawing low level ambient information out of a recording subtly adds realism and listenability to it.

I also found the Clearaudio to be an excellent cartridge for capturing the relationships of direct to reflected sound. More so than the Dynavector or the Shelter, the Concerto cleanly and clearly captured the moment of first reflection within the studio, refusing to muddy the distinction between direct and reflected sounds. In this respect, the Concerto was superior to the other cartridges.

Highs with the Concerto were clean and well integrated into the fabric of the music. At first I thought that the upper mids could be a little steely as electric guitars came out a bit too realistic at times. Over time, however, and as break-in became even more complete, the slight steeliness was revealed to be a sliver of added light in the upper mids along with its superb ability to get inside a sound texture wise; not a bad thing in many cases. Sibilance was well controlled and generally less splashy sounding than with the Dynavector and Shelter. In terms of trackability, this cartridge did very well, keeping images solid and stable. In absolute terms, the Dynavector and Shelter were minimally better trackers.

Overall, I liked this cartridge a lot. As well as any cartridge I’ve heard, the Concerto was able to express the emotion and vitality of a recording without overdoing any aspect of the sound or performance. The "bright light" that some have complained of in older Clearaudio designs is no longer a consideration. Certain aspects of a performance are "lit", but not to the point that I would hesitate to recommend the cartridge. This cartridge has body dimension. And there was the energy. Not even the Phoenix was better able to focus one’s attention so squarely on the moment while weaving together the tapestry of full symphonies as well as a rock power trio. Well done.

At 8.9 grams the Dynavector was much easier to balance out on the Origin Live tonearm than had been the Clearaudio. Recommended tracking force was 1.8 - 2.2 grams. As usual, I started off with the cartridge at the heavier down force. Backing off the weight in .1 gram increments didn’t really impact the sonics much at all. The XX2 was a solid and steady performer all the way down to its recommended low limit of 1.8 grams. Only when I went lower than that did tracking and tonal balance start to become an issue. VTA was interesting with the XX2. Whereas the other three carts desired being absolutely level at their recommended down forces, the XX2 sounded most realistic with the rear of the body being ever so slightly higher than the front. At the tonearm pivot I raised the back of the arm approximately 1/64" higher than what was dead level. At that point things locked in, and I left it that way throughout.

The XX2 uses a 6mm solid boron cantilever. It projected from the housing sufficiently far to make mounting with my two alignment tools easy and sure. Part of the ease in this respect was due to the narrowness of the cartridge body and the almost naked quality of the assembly. Everything was easy to see as I dialed in the cartridge for the lowest possible tracking error.

The XX2 had the lowest output of any of the cartridges auditioned at .28 volts. Still, it caused me no problems with any of the phono stages on hand.

The importer suggested that I load the XX2 at 30 Ohms. That’s pretty low, certainly lower than the PBN could be set at, and a lot lower than the lowest setting with the MinMax. Fortunately, the Herron VTPH-3 can load a cartridge at any setting you like. For this task I called Keith Herron and requested a set of 30 Ohm plugs, to which he asked if I could get by with a pair of 33 Ohm plugs which he had on hand… well of course. I tried the XX2 at 33 Ohms, 100 Ohms, 1,000 Ohms, 47,000 Ohms and with the Infinite Load setting of the Herron phono stage. Yup, 33 Ohms resulted in the best balance of tone and dynamics with the Dynavector.

The Dynavector was what I would call a medium compliance moving coil (10). As a result it fit well with the Origin Live tone arm, not deflecting significantly left or right on even seriously off center pressings.

Performance. My short phrase description of the XX2 is "safe." This cartridge was unflappable and prone to working well under any and all conditions I put it in. Whereas the Clearaudio, Shelter and Transfiguration carts required careful and considered set-up and alignment to sound acceptable, merely getting the XX2 in the ball park alignment-wise was sufficient to obtain good sound. Like the Clearaudio, it has a line contact stylus and was built to exacting standards. Why it was so easy to make sound good, I do not know. Which didn’t mean that I left well enough alone. As with the other carts, I set the XX2 up once, listened, and then fine tuned the alignment even further. I feel confident that my set-up resulted in the best sound that the XX2 was capable of.

The XX2 uses a magnetic assembly type called the "magnetic flux damper." I couldn’t help but think of the "flux capacitor" made famous in the "Back to the Future" movies, but I’m pretty sure they’re not the same thing. The flux damper seems to be a means of damping the magnetic flux density and lowering magnetic resistance within the generator. I don’t think I know what that means, except that the spec sheet with the cart says something like that. Which is fine by me as long as it sounds good.

The XX2 sounds much like the top carts in this survey, ‘cept it cost over six hundred dollars less. For a lot of people, that’s an acceptable compromise.

Maybe it’s the flux damper, but this cartridge sounds to be very low in those types of distortions that one usually associates with phono pick-ups of all types. I couldn’t make it severely mistrack regardless of the recording. I couldn’t even make it sound like it was going to mistrack except under the most grueling of conditions. In that regard, and I mean this in a good way, it sounded as solid and undisturbed as digital. And whereas the Transfiguration Phoenix and the Clearaudio Concerto did little to hide the surface noise they found, the XX2 de-emphasized ticks, pops and groove grunge. That could have been due to a slight softening of the highs with the 33 Ohm load that I was using. At 47,000 Ohms, or with the Infinite Loading of the Herron, the highs came up, got a little hard and the dynamics started to compress. I also heard the emergence of more in terms of surface noise. The Dynavector did very well with the 50 Ohm load option with the PBN phono stage. As with all things in audio a compromise was necessary, and like the importer suggested, the low impedance load seemed to strike the best balance, all things considered.

The XX2 had little of the sonic character or musical veneer that audio reviewers look for in order to classify a product generally. It was very neutral, very balanced (even if it was a little soft on top) and with the PBN phono stage it had moments of inspired power. The XX2/PBN combo had me listening to Ten Years After, "Scat Thing" from Ten Years After Recorded Live. The power image of Alvin Lee and his soaring guitar was mesmerizing… so I played it over and over. Bass was very good, probably extending a few hertz lower than the Clearaudio. The Clearaudio Concerto, while not going quite as low, had nearly the same subjective authority plus the bass clarity needed to follow a bass line more easily.

In all honesty, however, I found the XX2 the least exciting to listen to of the group. The relatively soft top end with the slight lessening of dynamic action when compared to the other pick-ups, lessened the emotional impact of the cart. Which must be put in some context. The XX2 was clearly the least expensive cartridge in the survey. It’s also being compared with some of the finest in the industry. It’s this way. The other carts seemed designed with an eye toward super excelling in some aspects (with the risk of falling flat in some others). The XX2 was very even across the board, never falling flat on its face, while never really blasting off either. Vocals were always good to excellent with this cartridge as were acoustic instruments, but I felt that the others were generally as good in every respect, and in some cases, noticeably better. Imaging was good, but it lacked the illumination of the Concerto, and it lacked the supremely fine (even delicate) delineation of the Transfiguration Phoenix. In my reading and research regarding the Dynavector, it’s known for its low distortion qualities, the lowest of many cartridges. I do not doubt that; it sounds clean. It’s failures are errors of omission and what it subtly subtracts from a performance. Nasties, this cartridge does not have.

Conclusion. For the person who desires the sound of a good moving coil cartridge, but not the hassles that many present regarding alignment, loading and compliance, the Dynavector DV XX2 MKII may be an excellent choice. It has a healthy, heaping portion of the best musically… while having the most reasonable price of them all.

The Shelter is a big cartridge with straight lines and a bold appearance. Short of the Red Rose, Rose Petal (measured in pounds weight wise), the Shelter 7000 was the heaviest cart on the block at 11 grams. Output was in the middle of the pack at .5, making it higher than the Dynavector, the same as the Transfiguration, but less than the Clearaudio.

I found the down force setting to be very important with the 7000. The manufacturer suggests no more than 2 grams - and he means it. Going slightly over that did no harm to the cartridge, but the sound quickly deteriorated as the down force went up. I settled for exactly 2 grams; no more, no less.

This cartridge took a long time to break-in completely. It fooled me. After several weeks of more or less everyday playing it sounded as if the VTA needed to be dropped. The tone was a little light, the midrange lacked some substance and I thought things should be better focused. So I started playing with VTA by dropping the rear of the cart down. I did so by lowering the pivot on the Origin Live tone arm and seemed to make progress in fits and starts. One thing would sound better, while something else would sound worse. I played with it the best part of an entire evening; adjusting, recording to CDR, listening, adjusting, recording… Back and forth I went an entire evening before giving up. The next morning I decided to forget the VTA for a while and just listen when I got the urge. With additional playing time the focus started to align and the midrange filled in. I noted that the highs were coming around nicely too. Break-in time on the Shelter had grown to twice what I had needed with the other cartridges. Only after the 7000 had settled in at its own pace was I able to properly set the VTA and trim in other set-up parameters. And after all that, the 7000 sounded its best with the body of the cartridge level with the platter; it didn’t need to be dropped at all. Let this be a lesson to you.

Loading was fairly easy in that I was using the Herron phono stage and the Shelter performed its best with the "Infinite Load." Which won’t help people without a Herron phono stage. But I also used the Shelter at 1,000, 100 and 33 Ohms with the Herron and the MiniMax for awhile and felt the 100 Ohm setting to be a good compromise for high end extension and foundation.* One thing became apparent with the 7000 as well as the other cartridges under comparison - Keith Herron’s Infinite Load setting was in most cases a blessing when it came to getting the most out of a pick-up. It doesn’t change the basic character of a cartridge, it just makes it better.

The stylus assembly is hidden away fairly well under the 7000, making alignment a bit of hit and miss. Maybe the easy alignment of the two carts above spoiled me somewhat, but aligning the 7000 required use of a magnifying glass to get a clear view of the diamond and cantilever. I didn’t get it right the first time, or even the second time, but that may have been due more to my carelessness than any difficulty inherent with the 7000. On the other hand, mounting the 7000 was a piece of cake compared to the guessing game that was the Transfiguration Phoenix. In this era of line contact stylus tips, the Shelter uses a nude elliptical. A throwback of sorts to days past, the elliptical does not have the narrow footprint in the groove exemplified by the line contact.

Performance. Once the 7000 was fully broken-in I came to appreciate the surefooted nature of its design and sound. My short phrase description of the Shelter 7000 would be "solid and driving." The 7000 wasn’t the finesse player that the Clearaudio Concerto was. Instead, the 7000 grabbed the basic character of a tune and ran with it. Even more so than the XX2 above, the Shelter built the music upon a bedrock of solid bass and driving rhythm. The quality of the 7000 might best be exemplified by listening to Tommy Bolin’s, "The Grind" off of Teaser. The complex harmonics of the power chord guitar intro were perfect for the 7000. The song develops a strong down beat and the force of it carries through the song - the ideal platform for the Shelter 7000. Though the Dynavector and the Shelter have some things in common in terms of drive, power and pacing; the Shelter does not share the softer highs of the XX2. This cartridge takes the power in the bass and extends that feeling up through the upper mids and highs.

The Shelter also delivered the goods in terms of inner detailing and timbre. Guitars, especially electric, have the inner shimmer and voltage charged vibrancy that they do in real life. Solos are particularly impressive as the very purpose of a solo of any kind is to focus the spotlight on a single instrument as it "shows off." With all of the front of the stage energy, there were times where some hardness would creep in making transient action a little more edgy than smooth. This was a minor thing that in some respects should be viewed as a positive. Why? Because the designer of the Shelter was willing to take a chance on being a little too edgy on a few occasions in the effort to faithfully and accurately reproduce leading edges without softening the rest of the time. Edgy vs. soft is one of the razor thin lines a designer must walk when choosing the parameters upon which to build. As is the case here, I think it’s better to get as close as possible to the line of accuracy rather than play it safe.

Interestingly, with all of the front of the stage action and activity, the Shelter was not the cartridge to reveal an abundance of low level information such as venue ambience, reverb and decay. My knee jerk response to the lessened ambient information was to look to the elliptical stylus of the Shelter. Known for being less demanding in terms of perfect alignment, the elliptical diamond is less precise in its tracing of low level signals than is the line contact, especially at higher frequencies. I don’t have the sophisticated testing equipment necessary to verify what my ears perceived, but the lessened low level air fits in with what I know of the type of stylus geometry used by the Shelter.**

Even with the lessened "air" of the 7000, this cartridge produced finely focused images and a superb sense of depth and dimension. The "Little Neutrino" recording referred to above truly "spaced out" with the Shelter. Side to side movements hidden or slightly obscured by the Dynavector and Clearaudio were clearly revealed with the 7000; as were small graduations depth-wise. That recording has space music stuff flying around at times and this cartridge caught all the movement in a clear and concise way, fitting in perfectly with the overall sense of clarity and excitement this cartridge was capable of.

Vocals were just about as good as it gets. Not quite in the same class as the Transfiguration in terms of organic texturing of human sounds, nor as grainless as the Clearaudio, the Shelter was still able to lend substance and density to vocals, especially massed vocal arrangements.

Conclusion. This is one interesting cartridge to listen to. The first thing one hears is the boldness and drive. It’s not over the top mind you, but a few hours with a properly broken-in 7000 will have you focused on the activity on the front of the stage and the dimensional images with precise lateral placement. Strong positives no doubt. After additional listening the ears turn to some of the finer aspects of the performance, and while timbres are true, a certain amount of "air" is missing at the back of the stage. With noticeably less ambient information presented than the Clearaudio Concerto or Transfiguration Phoenix, subtleties regarding the recording space and venue geometry are not as clear and present as they could be. Still, this cartridge conveys a dynamism that cannot be overlooked with clean leading edges on transients with true tones. A little edgy? Sometimes. But for many, this cartridge’s fundamental qualities will be an attraction.

* It would seem that if a cartridge performed extremely well with the Infinite Load (a super duper high load over a trillion Ohms), that a load of 47,000 Ohms would work better than 100 Ohms. Not necessarily. After repeated tests and observations, it became apparent that working with load settings was unpredictable and predicated on factors not readily apparent. If you own a Herron phono stage with the Infinite Load setting you’ve got a head start on the game, but if not… it’s hit and miss.

** As does the strong midrange.

The Transfiguration Phoenix came to me in a simple wooden box. No literature, no instructions, nothing. I didn’t even know what the manufacturer’s recommended down force was, much less how to load the cartridge. Yet, if compelled to state which cartridge of the five was may favorite, this would be it.* Even at its rather substantial price of $2,500 the Phoenix represents real value and a benchmark performance-wise.

The Phoenix is a medium compliance (15), medium output (.7) cartridge weighing 7 grams. Its Ogura line contact diamond stylus demands careful alignment. As with two of the other three carts, the Phoenix sounded best with the VTA level with the record platter. My experimentation regarding down force left me playing the cart at 2.0 grams, + .2 of a gram. The Stereophile Buyer’s Guide lists the optimum down force at 1.9 grams, so I was pretty close.

Set-up took some time. The cantilever is snuggled up underneath the body of the cartridge and isn’t easily viewed with a magnifying glass or otherwise once lowered down upon a recording or an alignment tool. I was forced to view things at a rather poor angle and estimate where the stylus was in relation to the crosshairs on my alignment tools. Then I played it. When it didn’t sound quite right, or the sound was leaning toward one channel when auditioned with a mono recording, I went back and aligned it again. Sometimes things got worse when I re-aligned things, sometimes they got better. If they got better, I did a little more of the same. A pain? Absolutely, but worth it in every respect when one considers the results. If anyone has a better set-up technique regarding this cartridge, please, please let me know of it.

As expected, the best loading was with the Infinite Load of the Herron. If you don’t have the Infinite Load option of the Herron; 100 Ohms was rolled, 1,000 Ohms was better, and 47,000 Ohms stunk. Again, all of the loading caveats stated above are still in effect. Be flexible.

Break-in was short. Which may be due to another reviewer having this cartridge before I did (assuming he played it). I’ll simply say that by time I had the cantilever properly aligned and the down-force had been determined, the cartridge sounded broken-in and was playing well.

Performance. Now that you already know how I feel about the performance of the Phoenix, the sense of anticipation regarding the outcome of this audition is materially lessened. But carry on we will.

In contemplating how to describe the sonic performance of the Phoenix in a phrase, I contemplated telling you that it was "balanced and transparent", because it was. But who wants to hear that? I also considered using "extreme accuracy." It’s that too, but the word "accurate" for some reason has bad connotations. Then I thought I’d be cute by calling it, "Supercalifragilisticexpiallodotcious." Too long. So, how about, "The best of everything"? I like that.

Which isn’t to say that the Phoenix is perfect, or even the best cartridge one can buy at any price, after all, Transfiguration makes a cartridge called the "Orpheus" which costs considerably more. But, out of this group of cartridges, and some others I have heard but haven’t officially included, the Phoenix represents a remarkable combination of superior qualities, without any one of those qualities standing out as better than the rest.

A superb tracker, grooves that had created difficult obstacle courses for other cartridges were a walk in the park for the Phoenix. It had the same unperturbable, low distortion tracking quality heard with the Dynavector, but without the frequency and dynamic limitations. One person commenting on the sonics observed that the "bass growled", while another that came over for a listen couldn’t get over the articulate and airy highs. No one that heard the Phoenix live, or via an LPCDR criticized it in any material way. And yet, everyone that heard it was able, and seemed to appreciate, something different about the performance.

For me, the cart’s salient quality was a grainless and utterly smooth, yet highly textured and finely detailed persona that went everywhere. No impact was too great, nor was any detail too small or well hidden to escape its purview. And it does all those things in a way which does not distract the ear or unevenly attract attention to any aspect of a performance (unless called for by the recording).

Recently, I’ve been seriously considering how various componentry portrays the context of a performance, meaning the layout of the stage along with the relationships of every sound source to every other sound source upon that stage. Part of displaying the complete context of a performance so far has meant a slightly more distant perspective than some consider accurate, or at least popular. In my opinion, the Phoenix approaches this problem of perspective and context by first assuring that the scale of every instrument, voice and sound is correct as recorded. A rolling sound field cannot be corrected, but it can be properly scaled and maintained relative to frequency, amplitude and time. Keeping this recorded information in proper relationships is difficult at any phase of the playback process, but I have to conclude that it is even more difficult at the juncture where mechanical motion is turned into a small, fluctuating voltage. Maybe that’s why context and proportion aren’t often discussed when talking about a phono cartridge. The ability to adequately maintain and express those difficult mechanical to electrical relationships may be the reason the Phoenix sounds so utterly natural and unrestrained.

The Phoenix is the finest cartridge I’ve heard to date regarding the rendition of context and proper proportions. And yet, it doesn’t accomplish the same by shrinking the stage and taking a firmly mid-hall presentation. It comes forward, but well short of the in-your-face approach that is vivid but not representative of the original recording in most instances. It’s so nearly right in this respect that I have difficulty imagining how it could be improved.

On to tone, dynamics, imaging, dimension, etc., etc. Though not quite as flashy sounding as the Concerto, the Phoenix was actually more exciting to listen to. First of all, the Phoenix was extremely quiet as a voltage generator, while at the same time retrieving maximum material from the groove. No cartridge can differentiate music from ticks and pops. But, it can accurately maintain the differences in terms of phase, thereby keeping the vinyl noise from integrating with the music - they can exist on different planes. The Clearaudio Concerto was a pro in this respect, and I think the Phoenix was even better. And when a cartridge is able to excel in this regard, the music is freed. It will almost jump out of the analog medium, thereby making tone, dynamic, imaging, dimension and almost all other considerations sound even better. So it is that this cartridge separates the music from the medium and for that reason alone was be an exceptional performer.

Drawbacks? A few. I’ve been using the Red Rose, Rose Petal for a number of years. That cartridge has a sense of remarkable transparency in the mids and upper mids. Some might call it bright, but in direct comparison to the carts here (even with so many miles of use on it) it still has within the restricted frequency range referred to the cleanest air and transparency of the group. The Phoenix, while being spacious and clear, lacks the almost startling clarity from front to back in the upper mids and lower treble of the Rose. Other drawbacks? Maybe, I’ll have to wait until I can get an Transfiguration Orpheus.

Conclusion. I’ve tried to take a different approach to writing this review; an approach that would best express the mechanical superiority of the cartridge, while at the same time, explaining the sensory impact of a product such as this. It’s fun - and it’s great auditioning a product so stable in its everyday performance; stable to the point of knowing that each day the Phoenix was in my system, it would sound exceptionally good and I would enjoy every minute spent listening to it.