Woo Audio 234 – Dream Machines

You know what drives audio Objectivists especially crazy? What raises their hackles, ups their blood pressure, acidifies their gut and tunes their bile-ducts into all kinds of angry belly-noises? Phrases that defy — nay, insult! — their world view about how things should measure, how things should perform, and most certainly about how things should be labeled. After all, “Science” determines what is true and right and good. Right? No. No. No.

And therefore I submit, for the delight of music lovers and for the dyspeptic apoplexy of the Apostles of the High Church of Scientism, the following label, because after several weeks of living and loving, I cannot think of a more appropriate one:

>>> Reference Amplifier <<<

Now this alone shouldn’t get the tummies rumbling from among the pencil-pushing propeller heads … but it refers to a Single Ended Triode monobloc integrated amplifier.

Did you hear that sound?

That angry intestinal-gurgling is the sound of institutional antipathy mixed with the obsessive compulsion to comment IN ALL CAPS somewhere, so that the record can be corrected to reflect Objectivist orthodoxy, namely that “Single Ended Triode” and “Reference” are mutually exclusive terms.

You may also consider this as something of an intervention. That the product of Objectivism is useful is never contested, but that such a philosophy has everything to do with Truth or has the authority to make wholesale dictums is not so.

In instances like this, where the whole so significantly transcends the sum of its parts, we are left to ponder of what use Objectivism is at all in matters pertaining to such things as the imminence of beauty. And while the disciplines of science were doubtlessly used to arrive at the end product, the Woo Audio 234 Monobloc was clearly designed with the beauty of music in mind and not necessarily the technical attributes of mere and mortal sound (and sound effects).

In this case we are hijacking “Reference” from the propeller-headeds because it has lost relevant and meaningful usage amongst that tribe. In fact, it nearly launches us back to Hirsch-Houck Laboratories where everything that measures the same, sounds the same. This has been disproven over, oh, four-plus decades of critical examination from our forefathers, so the hijacking is justified.


Woo Who?

The question is how any of this even got started in the first place. It is hardly the exciting business proposal one might bring before Angel investors or some Venture Capital group (for instance). How is it that one arrives at the decision to build tubed headphone amplifiers for a nascent and barely emerging market aimed at luxury audiophile headphone devotees?

At the time that Woo Audio was founded, Wei Wu and his son Jack were staring down a very small headphone market for audiophiles. Head-Fi.org wasn’t nearly the size it is today, and there was nary a mention of headphones in any of the audiophile rags that people tend to read. It wasn’t just a “niche”, it was an extremely narrow specialization with very few players in the tiny market. In fact, from a VC perspective, the High End Headphone Market might still be considered a very narrow, niche market and therefore the potential upside is capped too low for professional money to be interested (though I’m sure the broader, mainstream consumer headphone market is very, very interesting to VC, especially after a report in late 2013 that indicated sales projections were on track to exceed $8.2 Billion worldwide).

But that’s the norm for those of us who have ever made the decision to get into this “High End Audio” business in the first place. It was never a legitimate career-path by mainstream standards; you arrive at a career in HEA because you have a passion that makes every other (non-audio) option seem like a prison sentence. Like most bootstrapped start-ups, the money comes from savings accounts, equity in homes, rainy-day funds, family, friends, bake sales, blood drives … wherever you can get it.




The Woo Audio story begins with a plucky little eBay offering from back in 2003. I’ll let Jack tell the story:

“I grew up with tubes! Unlike my peers, they know mostly MP3 players. My father built a bunch of tube amps as long as I could remember. So many of them, I had all my toes and fingers all burned. If I recall correctly, there was only one solid state amp we keep it on the shelf. So the tube amp business was a unanimous decision from three of us (dad, brother, and myself). I didn’t know if it was a good idea but I thought it was just very cool. 

“Yes, the headphone world was tiny back then. It was suitable to my business model.  I started very slow. I just focus on one amp and one customer at a time without thinking about too much about making a profit. I had my full time job on the side so I didn’t have much financial burden. I think i made a good decision not to grow the company too fast. This allowed me time to set the company direction. Up till now, I still want the business to remain in the niche market and make innovative quality products.

“Woo Audio’s first product was the WA1, an OTL headphone amp featuring one driver tube 6922 and one power tube 6080. It was a creation from my father, Wei, and I. Dad was the builder and I helped to source all of the parts. Right from the beginning, we stumbled on finding a good power transformer with the specification we needed. It was not practical to wind a transformer from scratch since it was difficult to get good parts in small quantity. Thus, we decided to modify an existing power transformer. We unwound all the wires then wound it in our own way. In a few days of efforts, the prototype was done. We tested it with a pair of Sennheiser HD650 headphones and the combo sounded unbelievably good. Though, it was not in a presentable condition so we tried to make it look pleasing. The exterior was made out of a stainless steel mug as the transformer cover, aluminum window frame as the body, acrylic panels as the face and rear plates. All these parts were manually cut by a few basic tools.

“Finally, the WA-1 made its first appearance on eBay in 2003. Shortly after the listing, the product received a lot of heated discussion on head-fi because of the low price, promising specs, and some bold description. Many head-fi members were curious to find out if this was a scam or a “giant killer”.  A few days later, a head-fi member took the plunge on the WA1. We were so excited and we wanted the product to deliver in one piece so we stuffed packing box with cushion and taped the box  around three times! At first, I was hoping the buyer to give a 5-star rating and a positive comment on eBay. Surprisingly, the buyer wrote a lengthy raved review on head-fi. I was completely stunned as were many of the head-fiers.

“This was how Woo started the business. From the bottom of my heart, I deeply appreciate all the customers’ support. Without them, this passion will not stay alive.”

In 2003 I had no idea that the headphone underground was bubbling-up like this. It’s not for not being plugged-in, mind you. Hell, I remember trading tales with Tyll Hertsens (et alia) on TAN (The Audiophile Network), which was Guy Hickey’s dialup Wildcat BBS system back in the early 1990’s – before the Internet was the WWW! If one could say that HeadRoom was Ground-Zero for the modern audiophile headphone phenomenon, then Tyll – as its founder – was the grandaddy. But in 2003, I didn’t see nor hear much about the headphone enthusiasm at audio shows like CES save for Stax or Grado (two well-respected, old and proven brands).

I met Jack Wu a few years back thanks to my old and dear friend, Todd Garfinkle of MA Recordings. Todd had shown with Jack on an occasion or two, and had introduced me to Jack a few years ago when we were all talking about showing our wares together. At Capital Audio Fest 2012, I used the Woo WA5 (a 300B-based amp that will drive headphones as well as loudspeakers), along with the Davone “Mojo” mini-omni speakers that I was distributing at the time. At subsequent shows I got the chance to hear the Woo gear paired with so many headphones that it made my head spin. But what made my head rotate even more was the intense amount of traffic Woo was getting. The interest in high-end headphone listening wasn’t just surprising to me — it was gobsmackingly shocking!

This was coincident when brother Michael Mercer kept on and on about Audeze headphones to me that I eventually gave in, put the AKG 702s in a drawer, and had my ears opened and my mind blown with a pair of LCD-3’s. Everything sort of clicked for me once I got to spend serious time with my desktop rig. I finally understood what was getting all the headphonistas so excited.

During the New York Audio Show I got a chance to hear a prototype of the 234 monoblocs because I was once again sharing a room with Jack and Todd, and Jack had them on prominent display for anyone to try. It was the star of the show and, at a proposed $16,000 base price, it was almost intimidating. Who knew, nine months later, Jack would be offering me the world premiere review of the 234? I was excited, because now I could get to play with these bad boys under my conditions (vinyl) and I would get to push some loudspeakers around with them!


234 Monoblocs

For the quick technical expo:

First things first – this is an integrated amplifier, meaning you won’t need a preamplifier. It has three inputs – (2 RCA and one XLR).

The 234 monoblock allows the user to choose between three main triode tubes to drive either headphones or loudspeakers:

  • 45 (2 watts)
  • 2A3 (4 watts)
  • 300B (8 watts)

When using it to drive headphones, the user has the option – using these ingenious plug-in keys (OSKs) – to choose between these output configurations:

  • High Impedance Cathode Output
  • Low Impedance Cathode Output
  • High Impedance Plate Output
  • Low Impedance Plate Output

Combined with the different output tubes, this means that there are 12 possible options for matching these amps to any particular set of headphones. Further to that, real aficionados will roll tubes to allow for even more tailoring of sound. Jack provided me with a suite of mesh-plate tubes from Sophia Electric, and so I didn’t indulge in any tube rolling as I had no alternative triodes on hand save for some 811-10’s for my Berning Seigfried — and they don’t fit.

I will skip the unboxing, descriptions of knobs, and the rest of the word-stuffing usually found in old-world formula reviews. Bo-ring. Let’s get to the juicy bits:




What I can tell you about my experience with the 234 as a headphone amplifier is actually limited, because I only used the Audeze LCD-3s with them. I fed the amps from both of my turntables; the Klimo Beorde (with Soundsmith Boheme cart and MMP4 phonopre), and the Continuum Caliburn (with Soundsmith Hyperion and MCP 2 phonopre). After a considerable amount of trying out the various combinations of tubes and output configurations, I thought that the 300B with the High-Z Plate Output sounded best … and far better than anything I had ever poured directly into my ears.

Record after record I was getting drawn so deeply into the music. Do you know that feeling you get when you’re so high on music that you become beautifully disconnected from the world, like you’re just floating? If you know what it feels like to just melt away on a beach, laying down in the sun, your whole body goes limber as the salt breeze and ocean waves massaging the shore help you drift into a serious natural high – then you can begin to imagine how this setup interacts with body, mind, and spirit. The effect is way beyond therapeutic, it feels transformational. From Dead Can Dance, to Notting Hill Billies, to Arthur Grumiaux, to Brian Eno, to Ella Fitzgerald, to John Fahy, Beaver and Krause, Eric Satie, Wilco, Murcof, Earth, Boris, The Mars Volta, Sufjan Stevens, My Brightest Diamond, The Shins, Count Basie, Uncle Tupelo, Andrew Hill, David Bowie, Lester Bowie, Chester and Lester … you name it, I was totally immersed and completely overwhelmed. There is this (extra-dimensional?) quality to this setup makes the music impossible to resist, as you fall deeper into the musical “trip” and let the rest of the world float away.

The single-most involving headphone experience of my life, so far, were had with the 234 and the Audeze LCD-3s. Period.

I had the opportunity to run these amplifiers with the Oswald’s Mill Audio “Mini” loudspeaker, as well as my tried and true Sonus Faber “Extrema” – a 22 year old loudspeaker that can still embarrass some of today’s more ambitious and celebrated (and expensive) designs.


OMA Mini White

photo credit: Cynthia van Elk

The OMA Minis were already at the top of my list. I’ve been running them with Klimo TINE monoblocs (EL34 PP @ 40w). I consider the Minis nothing less than game-changers, and I’d go to my grave satisfied that I’d never need another upgrade if I owned these loudspeakers.

Combining the Minis with the Woo Audio 234 Monoblocs proved to be a lot of fun, and as I took the time to listen to the various output tubes I locked in on the 45, at 2 watts. I was fairly shocked that these 96dB sensitive speakers actually achieved really satisfying output with the 2w option! My second favorite was the 300B for its lusciousness, and then the 2A3, which wasn’t all that far behind the 300B. But, far and away, the 45 did the trick for me and so most of my listening via the Minis was done through these tubes.

What I can tell you about how the Woo Audio 234s with 45 triodes driving OMA Minis is that the combination amounted to the same level of eargasmic and near-hallucinogenic joy that I experienced with the LCD-3s . I shit you not. This was a level of immersive dimensionality and sweet sweet midrange magic that is usually reserved for describing Quad ESL 57s – not that these could be mistaken for Quads at all – but that this combo seriously produced the goods. And unlike the Quads, the OMA Minis/Woo 234s produced all the goods. That means dynamics, satisfying levels, crystal clear everything, delectable midrange, and just effortless-effortless-effortlessness. I don’t know what a Champagne Supernova is, but I imagine this was it.

I spent every morning for a couple of weeks burning off a few hours of not getting my work done because I’d be in the listening room playing records. I eventually brought my laptop in to try and do some work while I was listening, but it proved IMPOSSIBLE to pay attention to the work. That was the magic of this combo, and I can easily imagine any music lover taking these two components, adding some quality sources, and calling it quits – never reading another audio magazine again, saying “ta taa” to audiophilia and go on about the rest of their lives just buying and playing music. There’s no doubt that this is “get off the merry-go-round” material.



SONY DSCBut the big surprise was when I put the Extremas into play. Because they’re only 88dB sensitive, and because they use a power-hungry resistor/inductor network as a high-pass filter in the crossover (instead of the typical capacitor), I knew I’d need all the extra “gronk” I could get from these amps. I didn’t expect much. After all 8 watts is just 8 watts. And yet …

Though they didn’t get very loud (perhaps averaging 95dB at their loudest), the Extremas and the Woo 234s were a delightful match. They tended to sound a bit more distant than the Minis, certainly more reticent in terms of dynamic comparison, but they totally delivered the sweetness of the music. On some (but not all) vocal material they even tended to lend slightly more intelligibility of lyrics, and there’s that hot-chocolatey deep midrange magic that comes alive with instruments like the Cello and baritone sax. That said, I can’t wholly recommend the Woo 234s for loudspeakers with moderate sensitivity, such as the Extremas, even considering there was some seriously immersive magic coming out of them. The Extremas tend to fare better when driven with more resolute power.



Silver or Black? That is the question…


So who is this Woo for? $15,900 is a mighty sum, and if you want better tubes, the price gets pricier. In fact, if you want the full compliment of tubes you’ll be coming perilously close to the $20k mark. However, the Woo Audio 234 is one of the most impeccably-made amplifiers I’ve ever seen (or heard). Each one is built by hand in Woo’s workshop in New York to exhaustingly precise standards and tolerances. The 234 monobloc is unapologetically a Statement component from Woo Audio. Because they are integrated designs, you won’t need a preamp, and this increases the value proposition. Still, at somewhere between $18k and $19k for the full setup, we’re still talking a very serious sum. But let’s put some perspective on this.

One of the questions that invariably arises in explorations of price and value is the one that asks how much money the end-user will eventually lose over a lifetime of constant upgrading and trading-in, etc. If we’re frank with ourselves, the sum can oftentimes get scary. The secondary market has become the primary market, it seems, with the neurotic masses looking to minimize their risks by purchasing used gear at less-than 50% original retail. Risks of what? They already know, ahead of time, that they’re going to sell the thing that they’re about to buy. And so, the abusive cycle of constant “upgrading” takes hold (that, in itself, is a psychological oddity to me, this idea of being pre-dissatisfied, but that’s a subject for another discussion). Over the years, a  serious amount of money is invariably lost in this crazy merry-go-round. Woo’s products in general aren’t fit for that kind of trade-around (you hardly find them for sale on the second-hand market), and this is especially true of the 234 monoblocs.

Given the level of astonishing build quality and extraordinary performance, I’d suspect that the 234s would be selling for more than their asking price if they were being marketed through traditional channels — one of the strongest arguments for the direct-sale model, and possibly why this sector is doing so well to begin with.

So here’s the sum:

This is endgame stuff. And because it’s endgame, anyone spending their hard-earned cash on the Woo Audio 234 will be getting a tremendous value in return, because they will never feel the urge (or need) to buy another front-end for the rest of their audio lives (unless they’re neurotic types who can’t stop chasing all those magazine-made myths). As far as I’m concerned, the Woo Audio 234 Monobloc is like an original Ferrari Dino or a Lambo Miura — a simple, elegant, and undeniable classic.

It is cliché to say, but no less true, that I will feel no small amount of heartbreak as I send these back to Jack and Wei Wu – but I’m incredibly pleased to experience their magic. And if I happen to be in a position to buy a pair of these, you can bet I will, with no hesitation whatsoever.

This is endgame stuff, after all. True Dream Machines.


Woo Audio WA234: $15,900.00


>>> WA234 Website <<<


Comments are closed.