January 2002

The WAVAC EC-300B
Taking Your Ears on a Luxury Ride
Review by Wayne Donnelly
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  Let's face it -- we're pushovers for physical beauty. Whether it's a lissome creature seemingly right out of the Sports Illustrated swimsuit issue, a shiny top-down Jaguar parked insouciantly at a chic bistro, or -- for us advanced audiophiliacs -- a piece of big-ticket "eye candy" hardware, we feel an irrational yearning, despite (or perhaps because of) the improbability of actually possessing the object of desire. That's the sensation I felt at the 1996 CES in Las Vegas when I walked into the WAVAC room. Then and now, the WAVAC single-ended triode amps are among the most strikingly beautiful audio components I've ever encountered, and their prices -- a cool $20K for the EC-300B, for instance -- make it a long shot that most audiophiles will ever own one. So, what besides its visual appeal makes the EC-300B worth 20 large? Is that price justified? In case you're the impatient type who reads the last chapter of a mystery first, I'll end the suspense -- my answer turns out to be yes, for reasons that I'll explain if you'll come along through this review.

More Than Skin Deep? Oh Yeah...

Let me start by revisiting "eye candy." Something in that phrase suggests superficiality, lack of substance. But beneath its pleasingly symmetrical form and striking champagne-tinted finish, there's plenty of substance to the EC-300B. Take that chassis, for instance. No bent metal here; it's milled out of a solid block of aluminum alloy -- an extravagant but damned effective approach to vibration control. Other impressive touches include tube sockets milled from solid blocks of Teflon, fitted with gold-plated bronze phosphor contacts, and isolated from the chassis by elastomeric suspensions to suppress tube microphonics. Microphonics are one of the banes of SET amplifiers, especially those built around 300B tubes, which are notorious for ringing audibly during play. More on this later.

WAVAC uses only proprietary transformers designed jointly to WAVAC's specifications with TANGO, a Japanese company noted for the precision workmanship (and cost) of their transformers. WAVAC now winds all of their transformers in-house. The transformers are said to deliver high-speed, ultra-wide-bandwidth (20-100K in the EC-300B) performance and therefore contribute significantly to the cost of the EC-300B. Transformer quality is one of the most critical elements in any tube amplifier, and especially in SET amplifiers.

All WAVAC SET amps are based on a circuit developed by Nobu Shishido, an influential Japanese designer who also guided the implementation of the circuit by engineers of the WAVAC Audio Lab group. This patented circuit employs Inverted Interstage Transformer Coupling (I ITC) to feed an optimized signal to the 300B output tubes. A special circuit adaptation cancels DC magnetization in the I ITC transformer, enhancing bass performance and general harmonic richness. Altogether, the EC-300B uses five proprietary transformers: one power, two I ITC and two output.

Also unusual in SET amplifiers is direct-coupled circuitry. There are no coupling capacitors anywhere in the EC-300B. This pristine signal path is claimed to provide maximum purity of reproduction, and my listening to the amplifier has borne out this claim. In addition, the 300B heaters are supplied from a filtered DC source to minimize hum and noise. The amp also has a powerline input filter to reduce noise from incoming AC power. Not surprisingly, the EC-300B is easily the quietest SET I have listened to.

Remove the nicely perforated-for-ventilation aluminum bottom plate, and you see the impressively clean and organized circuitry, with very high-quality parts. WAVAC says it takes about 30 days to complete all of the steps of constructing an EC-300B, and I have no trouble believing them. This amplifier exemplifies the highest order of craftsmanship -- its beauty is definitely not just skin deep.

If you are familiar with SET amplifiers, you know that they typically require a lot of tweaking; some need rebiasing every time they're powered up. But the EC-300B is completely self-biasing. Even if you switch from one kind of 300B to another, you need not worry about the bias. This feature gets big points from me.

Before moving on to the sound of the EC-300B, let me just mention a couple of nice ergonomic touches. Simply powering up offers the tactile pleasure of pressing the oversize ON/OFF button -- and it's easy to find, even in the dark. More significant is the placement of input jacks and speaker terminals (gold-plated) at the rear of the top deck. This thoughtful touch not only makes those connections easily accessible, but also eliminates the frustration of trying to bend thick speaker cables to fit on the narrow rear surface. Bravo! Finally, WAVAC supplies a laboratory glass canopy to protect the tubes. It's very nicely built, but rather fragile -- the one sent to me, which admittedly had been shipped around quite a bit, arrived with serious cracks and subsequently broke as I was lifting it one day. But an intact one will do nicely to keep infant fingers and pet noses from the serious heat of the 300Bs. In my solo household I was happy to run the amp without the canopy -- which to my eye looks even more elegant.

Working It Out

As a reviewer I try to paint a clear picture of the component under consideration, but of course the performance I describe will inevitably reflect the performance of the entire system. That is particularly true in this case. My review of the Von Schweikert DB-100 loudspeakers, which appeared in the December 2001 Review Magazine, is especially relevant. Why? Because the listening experiences I describe there are all with the EC-300B driving the loudspeakers. The EC-300B was clearly the most musically satisfying in combination with those speakers of any of the amplifiers I have tried with them. I suggest that the interested reader go back to the archive and read that piece in order to fully understand what is said in this one.

Probably 90 percent of my listening to the EC-300B was through the Paravicini 312 pre-amplifier [review forthcoming], Vendetta Research phono stage, Basis 2800 /Graham 2.2/47 Labs Myabi, giant-killing Bartha-modified Pioneer 434 DVD player, and of course the Von Schweikert loudspeakers. The other amplifiers on hand for comparison were the push-pull 25-wpc VTL Tiny Triode monoblocks, the solid-state 50-wpc Andy Bartha monoblocks, heavily modified (and vastly improved) Golden Tube Audio 300B monoblocks, and, for a too-brief weekend, Audio Note Baransus . Unfortunately, the latter departed my house a day before the EC-300B arrived, so I could compare them only in memory. Those $30K monoblocks would have been perfect for a toe-to-toe with the WAVAC.

The other amplifiers, somewhat to my surprise, all performed well with the DB-100s. The Bartha amps threw the widest soundscape, had excellent extension at both frequency extremes, and suffered only slightly, in comparison to the tube amplifiers, from harmonic leanness. The VTLs were similarly extended, and delivered greater soundscape depth and slightly more precise imaging. The GTA 300Bs were, predictably, harmonically lushest through the midrange but seemed to lack  some dynamics relatively speaking.  I also detected a softness in the bass region and rather severe rolled-off in the treble. I managed to amuse myself with these quite different-sounding setups for three weeks or so until the WAVAC arrived. After about 20 minutes of listening to the EC-300B, I knew I would not be returning to the other amplifiers.

With the EC-300B in the system, I began to understand in a new way the potential of the DB-100 speakers. It was easy to break down the audio checklist qualities. The bass was not only as deep as with any of the other amplifiers; it also had more color and clearer pitch definition. High frequencies took on a relaxed, open quality that had not previously appeared. The midrange was harmonically more complete, and along with that, I could hear new low-level inner details that had previously escaped me. The soundscaping was at least as good as I heard with any of the other amplifiers -- actually it seemed to improve upon the best qualities of each of those amps. The dynamic nimbleness, the sheer speed of the WAVAC gave the music an immediacy, a rhythmic liveliness that was distinctive. Most impressive of all was the uncanny timbral accuracy, the purity with which voices and instruments were rendered. In that respect, the EC-300B surpassed any amplifier I have lived with for an extended period.

I regret that I did not have any full-range high-sensitivity passive-bass loudspeakers to audition with the EC-300B. I believe, however, that the amplifier would distinguish itself equally well with more conventional speakers. The Von Schweikert DB-100s, while actively self-powered in the bass, nonetheless derive their input signal from the main amplifier. The bass response changed quite noticeably with each of the amplifiers, and it was at its best when driven by the EC-300B. I suspect that the extraordinary transformers, direct-coupled I ITC circuitry and non-resonant construction all contribute significantly to that performance.

A Tale of Two Tubes

For several years WAVAC has supplied the highly regarded Western Electric 300B output tubes with the EC-300B. Now tmh audio, their North American distributor, offers buyers a choice of either the WE 300B or the Chinese-made TJ 300B with silver mash anode. Being curious about the difference, I had requested a pair of Western Electric 300Bs as well, and Jim Ricketts of WAVAC distributor tmh audio kindly included them in the shipment. To my great surprise, there was not much of a contest between the two. The TJ meshies were at once sweeter and more detailed, and dramatically smoother and airier on top. At first I thought the Western Electric tubes were better in the bass, but after more listening I began to prefer the greater speed and bass definition of the TJs. In addition, while I heard very little microphonic ringing from the WE tubes -- that vibration-damping construction was working -- I heard none at all with the TJs, even with the amplifier sitting only two feet from the left speaker. (For more commentary on these two 300Bs, check out the "300B Shootout" article by Thorsten Loesch in the December 2001 Review Magazine.)

How Do You Define Value?

My reference amplifiers for the last few years have been VTL 750 Reference monoblocks. These 750-watt, 150-pound behemoths, sporting a dozen 6550-C power tubes each, sound terrific -- and they can easily drive any speaker you could put in a home. They retail for $20,000, and to my mind they are unequivocally a good value. Now we have a 10 wpc SET that sounds sensational with very high-sensitivity speakers, but would be at a disadvantage for anything below, say, 93 dB sensitivity. And for me, it too is unequivocally a good value -- for the right customer. This amplifier is a jewel, the best 300B amplifier I've heard, and its engineering, parts and construction are of the highest order. It is in every way a luxury product, and if you have the discretionary income, I do not see how you could go wrong. Most of us, unfortunately, can't pony up $20K on any audio whim, and luckily there are numerous superb amplifiers that are more affordable -- including the WAVAC MD series. If you don't have the scratch, just think of the WAVAC EC-300B as the stuff that dreams are made of.

*Again, I wish to point out that the above numerical ratings are very much attributable to the combination of the WAVAC EC-300B and the Von Schweikert DB-100 speakers. 
*As I noted in the earlier Von Schweikert review, the soundscape ratings would be higher, I believe, in a larger and more conventionally proportioned listening space than my own.

 

Specifications

Frequency Response: 20Hz - 100kHz (-3dB)

Tube Complement: WE435A (telecommunications grade), 6L6GC, 300B

Power output: 10 watts per channel

Input Sensitivity: 1 Volt

Input Impedance: 100Kohms

S/N: 80 dB

Dimensions: 19" x 13.5" x 8.5" (WxHxD)

Weight: 60 lb.

Warranty: one year parts/labor; six months on tubes

Price: $20,000

Company Information

WAVAC Audio Lab - Sigma Co. Ltd.
1404-26 Nakada-Machi Yonezawa-Shi
Yamagata, Japan

Website: www.WAVAC-audio.gr.jp

US/North America Distributor
tmh audio
P.O. Box 751681
Dayton, OH 45475

Voice: (937) 439-2667
Website: www.tmhaudio.com
E-mail: info@tmhaudio.com