Wyetech LabsPearl PreampWyetech Labs Pearl Preamp Musical Joy From a Tube PreampThis review page is supported in part by the sponsor whose ad is displayed above Reviewer: Srajan EbaenSource: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive-1; Audio Aero Prima [on review...2495.00

Wyetech Labs Pearl Preamp Musical Joy From a Tube Preamp [Expired]


no longer for sale


This review page is supported in part by the sponsor whose ad is displayed above
Reviewer: Srajan Ebaen
Source: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive-1; Audio Aero Prima [on review]; Einstein CDP[on review]
Preamp/Integrated: Bel Canto PRe2; Wyetech Labs Pearl [on loan]; Einstein integrated [on review]; Audiopax Model 5 [on review] 
Amp: AUDIOPAX Model 88, Bel Canto eVo 4 Gen.II, Eastern Electric MiniMax
Speakers: Avantgarde Duo; Gallo Acoustics Reference 3; Green Mountain Audio Continuum 3 [on review]
Cables: Stealth Audio Varidig S/PDIF, Stealth Audio Indra (x2), Crystal Cable Reference speaker cable and power cords; ZCable Hurricane power cords on both conditioners
Stands: 2 x Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature for source components; Walker Audio Velocitor
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand and speakers; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets; Musse Audio resonance dampers on DUO subs; Mapleshade 4" solid maple platform under BPT conditioner
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan
Review Component Retail: $5,300


From my prior review exposure of his entry-level Coral linestage and our Blue Moon awarded Sapphire 300B monos, Canadian designer Roger Hebert of Wyetech Labs has proven himself as one of the rare valve engineers who is equally comfortable with low and high-level signals. If you thought this to be standard MO in the field, it's not. The requirements for ultra low-noise, highly dynamic preamp stages are very different from speaker-based drive & control challenges for amplifiers. Most designers will -- at least secretly -- admit that they're truly adept at only one and either need help in the other department by way of subcontracting or inordinate time to master something that isn't their native talent turf. Once you're talking tubes with what -- at least in general parlance and view -- are considered higher intrinsic noise issues, valve amp designers are often out of their depths when market realities force them to expand their amplifier lineup not with just any preamplifier but a high-performance valved champ whose basic specs will invariably get compared against the best of the solid-state contenders. 


Highly unusual then, Roger Hebert consumes tube-related noise and bandwidth issues of amps and preamps for breakfast well before following Alice down the rabbit hole into the lab. On his currently second-from-the-top non-inverting Pearl preamp, this translates into an ungodly +0/-3dB bandwidth of 3Hz to 950kHz (the ruler-flat spec is 15 - 200,000Hz) achieved with a grounded grid circuit bracketed by cathode followers fore and aft and three 6SN7WGTA NOS Phillips double triodes. While we're at specology, add input impedance of 50Kohm, output impedance of 600 ohms, output voltage of 3.5 Vrms (max 8.5) and slew rate of > 25 Volts/microsecond.


Single-ended connectivity provisions include 4 inputs, one tape loop and two pre-outs, with an international voltage switch, power IEC, fuse holder and power mains toggle completing the rear estate. The large gold-plated frontal brass controls, from left to right, select inputs, balance offset (+/- 5dB in 1dB stepped increments) and volume (24 click-stops from -60dB to 0dB). One toggle selects between tape/source, another between mute/on, this latter connected to two LEDs (one red for mute, one green for ready which lights up once a relay completes the initial 45-second thermal stabilization process).

Anything from the house of Wyetech is a mixture of only slightly gussied-up yeoman build and -- at their models' respective price points -- the finest parts that money can buy. The Shallco switches and ELMA volume control of the Pearl redefine the term "positive action" and the point-to-point wiring of the zero NFB linestage utilizes advanced two-sided Vector boards with contact turrets for the shortest possible signal path. The separate 200V/DC power supply board borrows from the top-line Opal with a double-pye choke filter, a large 30uF final polypropylene capacitive filter, a 2000uF electrolytic capacitor to passively shunt-regulate the 200 volts DC and a solid-state regulator on the filaments.


The chassis in the trademark lavender automotive paint bolts 1/8" to 1/4" thick aluminum plates to square corner posts via non-magnetic stainless steel screws for no-nonsense solidity. A 10-year warranty reflects on the maker's confidence in the trouble-free longevity of his product. The stock NOS valves are expected to last for 10,000 hours or more.


The box measures 17" W x 14.25" D x 4.25" H and weighs 18.7 lbs.


Talking to the two statewide retailers which carry Wyetech on either coast, I found out why there aren't more: Wyetech deliberately keeps the profit margins far smaller than usual for our capitalist country. This maintains final consumer prices at aggressively competitive levels that are by design below what other domestically producing firms have to charge to secure wider distribution. Part of the Wyetech appeal thus is a certain amount of high-value exclusivity backed by one-on-one support from the maker. This review page is supported in part by the sponsor whose ad is displayed above
Reviewer: Srajan Ebaen
Source: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive-1; Audio Aero Prima [on review]; Einstein CDP[on review]
Preamp/Integrated: Bel Canto PRe2; Wyetech Labs Pearl [on loan]; Einstein integrated [on review]; Audiopax Model 5 [on review] 
Amp: AUDIOPAX Model 88, Bel Canto eVo 4 Gen.II, Eastern Electric MiniMax
Speakers: Avantgarde Duo; Gallo Acoustics Reference 3; Green Mountain Audio Continuum 3 [on review]
Cables: Stealth Audio Varidig S/PDIF, Stealth Audio Indra (x2), Crystal Cable Reference speaker cable and power cords; ZCable Hurricane power cords on both conditioners
Stands: 2 x Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature for source components; Walker Audio Velocitor
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand and speakers; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets; Musse Audio resonance dampers on DUO subs; Mapleshade 4" solid maple platform under BPT conditioner
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan
Review Component Retail: $5,300


From my prior review exposure of his entry-level Coral linestage and our Blue Moon awarded Sapphire 300B monos, Canadian designer Roger Hebert of Wyetech Labs has proven himself as one of the rare valve engineers who is equally comfortable with low and high-level signals. If you thought this to be standard MO in the field, it's not. The requirements for ultra low-noise, highly dynamic preamp stages are very different from speaker-based drive & control challenges for amplifiers. Most designers will -- at least secretly -- admit that they're truly adept at only one and either need help in the other department by way of subcontracting or inordinate time to master something that isn't their native talent turf. Once you're talking tubes with what -- at least in general parlance and view -- are considered higher intrinsic noise issues, valve amp designers are often out of their depths when market realities force them to expand their amplifier lineup not with just any preamplifier but a high-performance valved champ whose basic specs will invariably get compared against the best of the solid-state contenders. 


Highly unusual then, Roger Hebert consumes tube-related noise and bandwidth issues of amps and preamps for breakfast well before following Alice down the rabbit hole into the lab. On his currently second-from-the-top non-inverting Pearl preamp, this translates into an ungodly +0/-3dB bandwidth of 3Hz to 950kHz (the ruler-flat spec is 15 - 200,000Hz) achieved with a grounded grid circuit bracketed by cathode followers fore and aft and three 6SN7WGTA NOS Phillips double triodes. While we're at specology, add input impedance of 50Kohm, output impedance of 600 ohms, output voltage of 3.5 Vrms (max 8.5) and slew rate of > 25 Volts/microsecond.


Single-ended connectivity provisions include 4 inputs, one tape loop and two pre-outs, with an international voltage switch, power IEC, fuse holder and power mains toggle completing the rear estate. The large gold-plated frontal brass controls, from left to right, select inputs, balance offset (+/- 5dB in 1dB stepped increments) and volume (24 click-stops from -60dB to 0dB). One toggle selects between tape/source, another between mute/on, this latter connected to two LEDs (one red for mute, one green for ready which lights up once a relay completes the initial 45-second thermal stabilization process).
Anything from the house of Wyetech is a mixture of only slightly gussied-up yeoman build and -- at their models' respective price points -- the finest parts that money can buy. The Shallco switches and ELMA volume control of the Pearl redefine the term "positive action" and the point-to-point wiring of the zero NFB linestage utilizes advanced two-sided Vector boards with contact turrets for the shortest possible signal path. The separate 200V/DC power supply board borrows from the top-line Opal with a double-pye choke filter, a large 30uF final polypropylene capacitive filter, a 2000uF electrolytic capacitor to passively shunt-regulate the 200 volts DC and a solid-state regulator on the filaments.


The chassis in the trademark lavender automotive paint bolts 1/8" to 1/4" thick aluminum plates to square corner posts via non-magnetic stainless steel screws for no-nonsense solidity. A 10-year warranty reflects on the maker's confidence in the trouble-free longevity of his product. The stock NOS valves are expected to last for 10,000 hours or more.

"Probably the most difficult stage of amplification in any system is the first, and the preamplifier has the primary responsibility of preserving the music signal where the key is to maximise the dynamics in the signal and minimise any corruption." [From Graham Tricker's website introduction to his Tron Syren preamplifier.] In a nutshell, my italicized emphasis here reflects a particular concept or notion. This notion has induced a veritable phase shift in your raised-on-passives scribe just this past year. Here's what it proposes - a unique role for the preamp where one half is passive (as in not adding any distortion artifacts - say, crystalline table water without any self taste) and the other active (as in maximizing dynamics - say, carbonated water with a deliberately boosted effervescence). 


Based on my experiences with two of today's contenders, I would now add a few more prospective aspects to the active part of this equation: namely optimization of the spatial dimensionality in the soundstage; and gutsiness/density of musical images. Now, I'm not suggesting you subscribe to this particular notion of what an ideal preamplifier should do. I'm merely suggesting that when demonstrated vis-a-vis a design that adheres to the passive approach -- and here I use "passive" not in its technical coinage of "no AC or DC components" but as an electrically active design that simply purports to do nothing to the signal -- one might find as I did that the properly executed active approach can be musically benign, emotionally more convincing and as such, provide a distinctly desirable additive function.


But, consider the implications. The maxim of HiFi is defined by its term: high fidelity or truthfulness to the signal. Anything additive and enhanced is, by definition, in violation of this maxim. Theoretically speaking then, the passive preamp ideal -- of doing absolutely nothing to the signal but passing it on exactly as received while merely modulating its voltage -- is the only correct and tenable one. You'd also think it's the only one of practical interest to recording or mastering engineers.

That said, the playback experience clearly lacks not only the visual dimension of a life performance but other sensory data. In the original venue, those become intermeshed with the sounds. In the home, this multi-dimensional experience is diminished to an ears-only affair. Most audiophiles who place emphasis on soundstaging hope to inject certain missing visual elements back into their listening sessions. They optimize their systems accordingly. Without it, they feel that the playback experience is rather flat or diluted compared to the real thing.


If sheer fidelity to the signal was the paramount thing, a seat in the recording studio would not only suffice but be the ideal and the dream. Ditto for ruler-flat frequency response and all manner of theoretically perfect attributes. Still, compliance with theoretical ideals of pure HiFi tends to leave most pleasure listeners cold. You could say that at the bottom of this dichotomy lies the age-old rivalry between truth and beauty. With preamps, there'll be devotees of either religion. Neither is wrong. Both are right as it pertains to their personal needs and biases. 

Click image to visit artist's website All this by way of setting the stage. This listener will declare a clear personal favorite and thus take shelter in one of the two camps without making it the ultimate or only one. This isn't some fancy word play to avoid criticisms or stepping on toes, either. There will be implicit criticisms. But they can't be absolute criticisms. They simply occur to you when looking at things from a certain vantage point. Looking at them the other way and from the opposing vantage point would simply turn your own presumed assets or superior attributes into undesirable liabilities. C'est la vie!


Put differently, tubes in general could be accused of being wrong because, as a breed, they manifest measurable imperfections e.g. deviations from the raw signal. Often, they're measurably and audibly noisier, too. Regardless, a high percentage of tube-using listeners with good ears and plenty of audiophile experience suggests that in the end, many audiophiles opt for beauty over truth. In fact, you could say that being true to beauty or music's intrinsic emotional charge might be called truth of a different kind than fidelity to "just" the measurable and quantifiable signal. Now we're duly primed for the relative truths of subjective audio reviewing as they pertain to my findings on the AUDIOPAX Model 5, the Bel Canto Design PRe2 and the Wyetech Labs Pearl.


For starters, the Wyetech Labs tube preamp is the antithesis of deep triode expectations. In fact, if you parked it behind a black curtain prior to your first encounter, you wouldn't hear valves at all. That is, until you swapped it out for the Bel Canto PRe2. This swap reduces microdynamic scale a bit. By itself, this likely wouldn't suggest tubes, just that one preamp is a bit more expressive with emphatic fluctuations and peaks. The give-away that likely would finally suggest tubes in the other candidate? It's the loss of a certain tacit and sculptural element in the soundstage. It's not that the soundstage shrinks in scope or flattens out. It's that the perception of three-dimensional space as mapped out by the performers (who do not move inward or forward) diminishes. Nothing so much happens to the musicians per se. But something concrete does happen to the emptiness between them. I can't come up with a better description than that space becomes audible and as such, enters into the aural equation in a way that was unequivocally missing before.


It's a bit like those heist flix. An over-aged (and over-paid) actor becomes the hi-tech thief who defeats unimaginable obstacles while being teamed up with a far-too-young, extremely attractive and nubile female accomplice. They finally sight the precious object. Our superman bids her to stop, whips out a miniature aerosol can and sprays a mist. It temporarily renders visible those secret infrared beams that would trip the alarm if interrupted. The beams were there before but only the special mist makes them visible. This adds a new geometry to the scene. It organizes it differently and something about your perception, of context and relationships between the fixed objects, changes. This is similar to how the Wyetech Pearl establishes a permanent "mist" that makes previously invisible relationships between the performers visible/audible. My description sounds far more complicated than it really is. Anyone can hear this concretization of space or dimensional holography that differentiates the tubed Pearl from the non-tubed Bel Canto.


If this is perhaps somewhat expected by those familiar with generalized distinctions between truly superior valve vs. transistor preamps, what might come more of a surprise is that in the areas of micro-detail -- which is always related to S/N ratios -- the Wyetech unit refuses to play second fiddle. There's no doubt that the PRe2 is dead quiet and, from the three preamps under considerations, probably the one with the keenest distortion and noise figures. Alas, this does not translate into audible superiority with detail retrieval - and if it did, this is more than overshadowed by the dynamically and spatially more expansive mien of the Pearl. Though it might seem tiresome to say, the transistor preamp here is clearly drier and less involving than its valved counterpart. Truly -- and while we're at sodding generalizations -- the latter is far more solid-state than not. It shuts the door on common valve liabilities such as frequency-domain limitations, undue textural density from THD artifacts and the concomitant sense of slowness, blunted transients and compromised rise times.

On those fronts, it's simply wide-bandwidth, linear and neutral, just what a "passive" design like the paragon-of-neutrality PRe2 demonstrates to perfection. Where the Pearl goes beyond -- and it's arguable whether that should properly say "beyond neutrality into additive behavior" -- is in the twin domains of dynamics and space. Especially the latter addition is far from faint and so impressive that I had early on contacted Wyetech's Roger Hebert for a sales price. Pulling the trigger was contingent merely on the arrival of the Model 5 just in case. (Prior experience and encounters with Eduardo de Lima have me convinced that we listen for very similar things. If he launched a preamp, it behooved me to include it in my decision-making process).


Where the PRe2 smokes all comers is in the remote/features domain. The Wyetech Pearl has no remote, period. The AUDIOPAX comes with an RF unit that controls volume up/down (with the RF receiver in the power supply which thus had to be cased in plastic to avoid an actual antenna). In that regard, the Bel Canto is as modern as modern gets. The AUDIOPAX makes minimal concessions to creature comforts and the Wyetech none. Despite owning what I think are some of the finest tube amps made if you neither require higher power/gain nor have silly money, the additive (or insert 'heightened', 'optimized' or 'enhanced') small-signal dynamics and 3-D effects of the Wyetech Pearl preceding it were clear as day. This makes me hesitate to categorically state that the PRe2, in this regard, is ideally suited for those tube amplifiers which are already space champs and thus need (or could use) no help from the preceding component.


The PRe2 -- and in previous guises as the PPe6 and PRe1 -- has been my constant preamplifier of choice for a few years now. It's never burped even once and always gave me exactly what I expected - essentially nothing but complete honesty and invisibility. I believe it to be as neutral as any listener can assess seeing that nothing makes a sound by itself. By the time there is a proper chain and sound, it's hard if not impossible to determine what, exactly, each associated component contributed to the final picture. From the perspective of high fidelity as suggested earlier, the PRe2 is as good as imaginable. I've done bypass tests -- the excellent Birdland Odeon DAC/pre comes to mind -- and the Bel Canto always acquitted itself as essentially inaudible despite additional circuitry and interconnect. It thus fulfills to perfection the demands and goals of the "passive" camp of preamp design. It views this component's goal as that of a radio broadcast transmitter. It sends signals through thin air. For argument's sake, air can't affect the signal in any mechanical or electrical way. What goes in comes out. If that's what your expectations for a preamp are, the Bel Canto PRe2 is your man (or girl).

If you want exactly that plus dynamic/spatial optimization, the Wyetech Labs Pearl is single, available and oh so very willing. If you want what the Wyetech does plusadditional physicality -- the opposite of invisible stereo ghost images -- plus completely unique adaptability which has already proven its worth with Nelson Pass' FirstWatt F-1 current-source unit, then the AUDIOPAX is the only one that can cross off every to-do item on your ambitious shopping list. In a nutshell, the AUDIOPAX doesn't sound like any solid-state preamp I've ever heard. Reports from Brazil suggest one might have to go as high as the $23,000 Accuphase to find its -- non-morphable -- transistor equal. Bob Parish, Shanling's importer for Brazil, tells me that like Fernando Andrette of Brazil' HiFi magazine, he owns a Jeff Rowland Coherence. He too was "shocked" to hear the Model 5, confirming Andrette's findings as reported in his review. Bob's now all set on acquiring a Model 5. 


Well, he ain't getting this one - it's mine and staying. I'll have far more to report to do justice to its TimbreLock facility and procure a few more amplifier loaners to do a comprehensive test. However, this much I already know: The Model 5 sounds like the tubed Wyetech Pearl but uses no tubes. Valve-related concerns go out the window. As if that weren't enough, it goes one step beyond the Pearl. It acts as though it drove on balanced power. By that I refer to the same kind of robust, solid, fully incarnated images that I hear as a sonic signature from balanced power conditioners. I assume it's the same kind of observation that caused Roy Gregory to use the word "authoritatively" and compare the Model 5 to the Tom Evans Vibe. Call it gutsy, call it fully fleshed out - it's an obvious quality but rare in this particular manifestation. Tube preamps that can do that tend to steal from transparency and speed to pull it off. High-gain preamplifiers that are body champs tend to be noisier. The Model 5 doesn't take away anything elsewhere to produce this acute thereness. It's not romantic, soft-focus, fire-side thereness but high-resolution, low-noise presence-on-steroids. It's the aspect that dialing in the TimbreLock seems to control most noticeably. 


In many ways, this makes the AUDIOPAX Model 5 more unique even than its tubed amplifier brethren. They're tube, they sound tube, albeit with a twist. The preamp pulls off the same stunt but subtracts the valves from the equation. It takes no crystal ball to predict that if de Lima can achieve this with a preamp, it can only be a matter of time until he applies the same principles to amplifiers and builds tube amps without tubes. Oy veh - now that would really mess with a few heads, wouldn't it? For now, do a Rosemary's Baby head spin for the Model 5. The long wait was definitely worth it. This might be an even more radical product than the Model 88s. Expect an addendum that will investigate the TimbreLock in detail and outside of today's comparative context. For now and based on what I'm familiar with, the Model 5 gets my vote as the perfect passive/active preamp implementation. It's passive in the areas of transparency and linearity and thus "solid-state". It's unusually active in maximizing dynamics, space and image density and thus becomes "tube". 


Last but not least, its unique adaptability makes it the perfect reviewer's tool to henceforth give all incoming amplifiers the best shot at showing off what they can do. They'll no longer telegraph suspicions about being restrained by possible preamp mismatches. And while it stands to reason that cost-no-object preamps will outperform the Model 5 in this or that regard, it stands alone regardless of price with its TimbreLock feature [above]. And it's rare, to say the last, for doing that tube thang without a single glass bottle. It's the perfect excuse for this valve-enamored fossil to go transistor and smile all the way to the listening seat. Now, if I could just find a bloody amplifier to pull the same stunt. I'd kiss tubes good-bye for good and just leave 'em in my Zanden which thus far, has beaten all transistorized comers to remind me that I gotta have my valve fix at least in the source. And amps... but the Model 5 is making me darn suspicious now that the amp thing could change. I have visions of a Brazilian designer picking up where Bob Carver and his famous transfer-function experiment left off. And while that's perhaps an unrealistic dream, the Model 5 is very real indeed and truly special. 


I feel the same about the Wyetech Labs Pearl. Except for the AUDIOPAX's added image density and its perhaps even more accelerated dynamics, it's aurally cut from very similar cloth. The Bel Canto PRe2 of this group is the one that seems just a bit too - er, neutral by comparison. But if neutrality is your poison, it's clearly the one that walks out of this match the winner, as The Invisible Man so you won't ever see it leave. So simply define your needs and expectations and select accordingly from these three preamps that, in the mid-priced sector of High-End audio, are still approachable and all first-rate examples of their respective design philosophies. Life in audio is good, don't you agree?
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