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Let's recap Gilwin Tan's technical explanations. To properly load the 300Bs in the most power-challenging range of music -- the lowest two octaves -- SilverTone has eschewed the usual load resistor on the output bottles. They favored a monstrous anode choke instead. This mondo coil adds the necessary inductance to liberate the rather small output transformer from bestial proportions. Remember, the output trannies are permalloy parts. To remain fully linear into the bass at full power, they would have to go seriously steroid to expand their inductance and compete fair and square with the bass of conventional silicone-steel cores. But even size alone apparently wouldn't have done the trick. DC in the transformer had to be eliminated to allow the desired use of the permalloy parts. Enter the parafeed circuit. In my admittedly non-technical mind, I'm inclined to view the choke/output tranny arrangement as a split-duty compound part. The anode choke does the heavy lifting, the permalloy core the suave tone thang. Or so theory and marketing predict.
To evaluate the Model 3.2 in the context of more conventional 300B amplifier architectures, I performed a direct A/B against the previously reviewed Canary Audio CA-308s. All used supplied mesh-plate output glass which, incidentally, is highly microphonic. Simply flick one tube and hear it ring out like a bell over your speakers. I ran these amps off my Music First Audio Passive Magnetic in +6dB step up gain mode. This would eliminate additional THD contouring from my two in-house tube preamps, the ModWright SWL 9.0SE and the overachieving Hyperion Sound BEC-P25T. Using a passive preamp should additionally shed light on each amp's self-noise behavior into highly sensitive speakers. It's an oft-overlooked aspect of such setups that redundant gain in the preamplifier stage can be the primary noise culprit, not the amp.


Interconnects were two pairs of Stealth Audio Indra. Those are still the finest interconnect I've heard when money is absolutely no issue. (For anyone still sane and with a life outside audio, I recommend the Zu Cable Varials as very close seconds. I own two pairs of Varials as well and use them as a real-world reference). The 10.5" bottom shelf of my Grand Prix Audio Monaco isn't tall enough to accommodate the Model 3.2 whose triodes top out at 12" off the ground. I thus parked the SilverTone humdinger on the floor. Did I tell you that for all its compactness, the Singaporean amp weighs like a boat anchor? With the Canaries directly adjacent, I could conveniently switch interconnects and output tubes to engage in that most primal of all audiophile pursuits - the dreaded/celebrated shoot-out.


The remainder of the system were the famous Zanden Audio digital separates in I²S clock-link mode with a 7308 in the DAC plus my Zu Definition Pros. I run their bass arrays off my two AudioSector Patek SEs bridged to mono, with the Rane PEQ55 serving as low-pass filter, room correction device and infrasonic linearizer.


This bi-amp arrangement is counterintuitively transparent to the main amp's bass prowess. That's because the Definitions' frontal arrays run wide open to well below 35Hz (rolled off, naturally, but it's exactly the relative delay or premature onset of roll-off, the transient attack and overall control in their lowest range that's telling about whatever amp drives 'em.)


My reference micro power tube amp is the stunning Yamamoto A-08S, a 2wpc 45 amp that in comparison to the Canarys actually had robuster, more extended bass if you can believe that. The Yamamoto would thus stand in as a personal reminder of my customary base line.

The substantial wire windings around iron and permalloy cores inside the Model 3.2 meant that pre break-in, bass was anything but impressive. Rather, it was soft, attenuated and a bit - um, amorphous. Before I radio'd Houston for help, I logged a few hundred hours. Sure enough, the bass not only came around but ended up becoming one of the highlights of this unusual amplifier. This statement, needless to say, is texturally qualified by this amp being a zero NFB single-ended valve design. Bass isn't overdamped or chiselled from granite. But when compared to compadres in its class, the 3.2 clearly justifies its considerable physical weight by delivering equivalent heavyweight bass. Extension down low gave the stiff finger to personal notions on 300Bs. Having the CA-308s on hand meant that my 300B reference wasn't imaginary but solid. The team around Gilwin Tan has in fact very much done its homework. The Model 3.2 successfully compensates its circuit for the predicted compromises in the lower two octaves and those oversized anode chokes work with a vengeance.


With that out of the way, I was most keen on honing in on the permalloy advantage. How would it telegraph sonically - exactly? First off, coming from the Emission Labs mesh-plate 45s in the Yamamoto, the Model 3.2 retains what I think of as the quintessential 300B signature. That's slightly rounded-over leading edges for broad-band softness. To my ears, it surrounds the musicians with a bit of cotton batting. That diffusive mien is especially relevant on Pop productions, those you simply know to be anything but soft. Take something harmless like Ishtar Alabina's Je said d'ou je viens [Atoll 8345100962], the latest solo outing of Alabina's lead singer who had previously jumped on the Gypsy Kings wave by adding Arabian influences. Here she mixes her outstanding pipes with French pop, Tsifeteli bellydance rhythms, African rap, strings, drum machines and other production-heavy accoutrements.
The 3.2 had plenty of taut boom-boom. Dance-floor SPLs per se and relative bass output vs. midrange and treble weren't the issue either; at all and quite to the contrary. Where things fell a bit short was rather in edginess - not the bad kind (that's expected with 300Bs that don't do treble nasties) but the good kind where the word edginess substitutes for bite, incisiveness, life factor or directness. Granted, I find this to be true for most 300B SETs (Wyetech Labs Sapphires and Manley Labs NeoClassic SE/PP excepted). This isn't really a complaint then as it is confirmation that in this regard, the SilverTone fulfills rather than transcends the 300B norm as it does so ably in the bass. Grittiness and hard-core nearfield antics are not why you'd own this amplifier. It's not that it doesn't play Rap or TripHop - of course it does. Its more polished demeanor simply means a delivery that isn't entirely uncut on more brutal fare. Having established again that I'm not a fully committed 300B man, let's evaluate the Model 3.2 on its own terms. Does it offer tonal or textural refinements over a non-permalloy amplifier?
Having already admitted to non-approved shallow fun music, we'll pick something from the approved audiophile list for this tonal/textural exercise - Paula Morelenbaum's Berimbaum [Universal/Mirante B0003695-02], a thoroughly modern bossa/samba exploit; and one of my favorite discoveries of 2005, Göksel Baktagir's Hayalgibi 2 [Akustik], a dreamlike instrumental meditation between Turkey's grand master of the kanun and piano and violin (thanks to Sezai Saktanber of SilverFi for introducing me to this far-out masterpiece).


Man has Paula got bass - not the girl, this particular album. I had to change the gain setting on the Rane which still reflected the prior Yamamoto balance. The challenger from Singapore was set to transform fleet-footed Brazilian Jazz into a bit of a stoned-out dance floor fest. That's how potent the 40-80Hz band came across prior to rebalancing the Zus' tonal balance. Berimbaum sports some righteous, fully tricked-out, nether-region-mining grooves. Having just recently discovered this album, I wasn't quite prepared. I expected instead something romantic and gentle, in the vein of Paula's Morelenbaum 2. Duly educated now, it was child's play to switch between the Canarys and SilverTone and note the differences.


The Canarys are more lit up, with more energy on brushed and struck cymbals for example. They have a tighter overall grip on the tunes. Mid/low bass is clearly less pronounced though also less sonorous than the Model 3.2 which is more ringy but hung like a horse. That small broad-band seasoning of diffusion already mentioned with the SilverTone -- translating as softness and roundness -- becomes tangier with the Canarys. Honey is traded for salt if you will. For a listener with 45 allegiances, the Canarys are closer than the SilverTone. The Californians clearly benefit from superior while more conventionally cored transformers themselves, designed, as per CEO Tony Dong, "by the guy who used to do the transformers for McIntosh."


So the transient/bloom balance is a bit more front-heavy with the Canarys, more rear-heavy with the SilverTone - for 300B single-ended amps. What about tone, presumably the - er, core attraction of 300Bs? Truth be told, dominant for this listener was the bass-leading, treble-following nature of the 3.2's voicing. Combined with the slightly rounded-over transients, it rendered the amp a bit darker and subjectively slower than my personal ideal. Add the looser manner whereby especially the lower registers aren't as well-damped as with the less endowed Canary. Rather than tone per se, control and tonal balance became the overriding personality traits for the permalloy proposition here.


Soundstage thereness is pretty intense with the SilverTone, this nearly predictable with 300Bs but even more so when the lower registers are as massive and extended as here. Subwoofer fanatics rarely get respect since the assumption going in is that they're explosion fiends and wannabe rappers and 'hoppers. What detractors forget there is that soundstage realism -- the ability to hear the original recording venue or mixing board faux ambience -- depends very much on a system's ability to retrieve extremely low-level cues in the lowest octaves. Superior (stereo) bass is mandatory for the ultimate soundstage magic. Here the Model 3.2 sets an admirable standard especially for single-ended no-feedback tube amps though I'm nearly inclined to call it somewhat reverse linear due to its potency in the lower octaves. Likewise, projection power is magnified. Contributing to this sense of scale are excellent dynamics whereby crescendi reach farther and the subliminal sense of "gathering storms" during their onset is strong, meaning you don't sense restraint or premature climaxing but peaks last and swell and finish off emphatically.

Though I really tried, I couldn't put my finger on the permalloy factor. I'd have to hear an identical Model 3.2 whose only difference was the core material to know what the permalloy contribution is. If I understood the technical explanations correctly, that's nearly impossible since so much about this amp has been specifically tailored and optimized for those cores. Simply substituting them would likely make quite a mess without also adjusting other parameters. This leaves me in limbo when it comes to pronouncing judgment on these parts which this company is so proud of. I can tell you, exactly, what this amplifier sounded like to me. I cannot tell you which portion of the sound -- everything, specific elements -- are due to the permalloy cores.


The amp's a low-to-medium rather than hi-gain device and very quiet in operation. If it compresses at happy levels, those remained outside anything I tried given the constraints of my setup and hearing. High-frequency extension could well be linear compared to the vocal range. Still, from the midbass on down, there's a clearly perceived rise in amplitude which makes the treble seem subdued by comparison. I'm not certain what design parameter to cite as the reason for the relaxed rather than grippy articulated behavior displayed. Some might point at control and damping factor. I'm not sure. The Canary monos probably didn't have any more in their favor to win that race. Take Baktagir's kanun, a Turkish zither with plenty of trills and embellishments played on taut strings suspended over a relatively small cavity to be well damped. There's a goodly amount of overtone content that surrounds this instrument like a miniature aura, protruding by just a millimeter around the fundamentals and dying rapidly, visible/audible just like fine spray or mist.
Simply put, the Canary sound is mistier in that sense, with more fire flies flitting about the soundstage, glittering and extinguishing. It's tighter and more compact. The Model 3.2 sound is looser and cast across a broader soundstage. Highly percussive, driven fare has impact and weight -- that bass again -- but timing precision reliant on speed and articulation incurs a bit of relaxation. In the final analysis, the Californian aesthetic strikes me as ultimately more linear and hi-rez, the SilverTone -- the name alone gives it away -- as more romantic and voluptuous and cuddly but also, dynamically more robust. Mind you, reviewer habit means that these distinctions are overdrawn for effect and communicative purposes. It's all about degrees and shades. Lastly, something like a KR Audio or Emission Labs valve instead of the supplied bottle would, based on prior experiences, go quite a long way in shifting the SilverTone personality in the other direction if desired.
The Model 3.2 is very well put together, cosmetically attractive in a cool Nordic way and never misbehaved even once during its stay. Upon power-up, there will be some hum over highly sensitive speakers which fades to nothing in a few seconds. The chassis gets quite toasty and the considerable weight concentrated over a relatively modest footprint coupled to how high the tubes mount atop the casing means that a sturdy shelf with plenty of head clearance is a must, a top shelf preferable. Based on what I believe attracts most prospective 300B enthusiasts to this tube in
the first place, the SilverTone Model 3.2 is a very welcome addition to the genre and one that doesn't suffer the usual excuses made for bass weight or extension. Ditto for amorphous core output transformers. This amp's anode inductors put a lie to any notions of inherent compromise. The 3.2 isn't another me-too product and for what's on offer, very fetchingly and fairly priced. Congratulations, Mr. Gilwin Tan and collaborators!
SilverTone Audio responds:

Mr. Ebaen,
This review very much covers everything our design goals for this amplifier were. Many audio enthusiasts have discovered the joys of what single-ended tubes and highly efficient speakers bring forth. Many are now using highly efficient speakers in domestically acceptable cabinet sizes which sacrifice the bottom end and are a little shouty at the top of their bandwidth.

The important thing to remember is that the Model 3.2 puts out only 8wrms/channel so naturally, the speakers completing the systems are often these very efficient types. Instead of focussing on just our amplifier, our design approach was directed at a systems approach. We deliberately tilted the tonal balance of the Model 3.2 slightly to the warmer and more romantic relaxed side so that it will complement these speakers well.

We would like to express our deepest thanks for this excellent review. Also, we would like to take this opportunity and inform US readers that audition of the Model 3.2 is now available at Jeffrey Catalano's High Water Sound in NYC.

Gilwin Tan


Srajan Ebaen comments:
I'm naturally much pleased that my observations and the engineering team's goals overlapped so precisely. It bears repeating then that the Zu Definition Pro with its rear-firing and equalized array of four 10-inch woofers per side and resultant solid extension to 16Hz ended up not so much complementing the inbuilt upward tilt in the amp's bass response for a combinant flat but rather, exaggerated it. My descriptions of this action therefore must be tempered by the reminder that it will be the very rare 8-watt copasetic speaker that wouldn't benefit from the amp's "bass boost" exactly as it was intended. My compliments again to SilverTone Audio for thinking practical and with deliberately the amp/speaker interface in mind. That's as it should be. Had I used Fostex, Lowther or equivalent high-efficiency speakers with restricted bandwidth and the usual presence region lift, the Model 3.2 would have been the perfect mate.
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