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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 2000P/5000S
Preamp/Integrated: ModWright SWL 9.0SE; Music First Audio
Amp: 2 x Audiosector Patek SE; Yamamoto A-08S; Canary Audio CA-308s
Speakers: Zu Cable Definition Mk 1.5; Gallo Reference 3
Cables: Zanden Audio proprietary I²S cable, Zu Cable Varial and Ibis, Zu Cable Birth on Definitions; Stealth Audio Cable Indra, MetaCarbon & NanoFiber [on loan]; Crystal Cable Reference power cords; ZCable Hurricane power cords on both conditioners
Stands: 1 x Grand Prix Audio Monaco four-tier
Powerline conditioning: 2 x Walker Audio Velocitor S
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets
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: $2,500

Even ein totaler Kulturbanause like yours truly -- a cultural ignoramus i.e. a lost soul that doesn't spin vinyl -- has at least heard of J.C Verdier's Platine, a turntable that is the French and far more modern counterpart to the Garrard 301 of England. Cognoscenti regard it as a true classic and whisper its name with reverence. Many would commit crimes to own one. That the firm is equally deep into valves most of us Yanks don't know, primarily because distribution of Verdier amps -- or turntables for that matter -- hasn't exactly been happening on any grande scale in our New World provinces.


Mr. Ming Su is committed to rebalancing our cultural deficit in this regard. He's importing GOTO components from Japan and now select items from Verdier's catalogue. Today's component is part of the Triode Spirit family of amps which celebrate the direct-heated 300B, 2A3 and 845 triodes in both amp and integrated forms. With the current resurgence of interest in 45-based amplifiers [Deja Vu, Fi, Ram Labs, SAC Thailand, Sun, Wavelength, Yamamoto], the other J.C. -- Jean Constant -- has authored a 45 amp based on the existing Triode Spirit 2A3 (45s and 2A3s are practically interchangeable but most designers will optimize an amp to run either one or the other valve). Unusually, this amplifier includes a switch to select between AC/DC-heater operation.


From J.C.'s website, we learn that "... the attraction carried on by the great audio triodes with direct heating of the filament is growing more and more. It is no longer possible to be ignorant of their qualities while belonging to the High Fidelity world. Actually, three types are readily available covering virtually all requirements. Those are the 2A3, the 300B and the 845... Now, let us take a close look at the obstacles we must clear to obtain perfection (yes, it is possible).


First of all the hum, generally caused by the power supply circuits. Each model of the Triode Spirit line uses a regulated power supply. Under all circumstances, it provides a constant voltage for the amplification stages. The regulated power supply, expensive to realize for the 2A3 and 300B models, becomes a real technical challenge for the 845 as that needs a plate voltage of 820 volts. This power supply is intricate to design (see the article in Sound Practices Issue 14) and it requires the use of 3 tubes in the 2A3 and 300B amplifiers or 4 tubes in the 845 amplifier to work properly.

Response at low frequencies: A detractor of S.E.T. amplifiers will say, "Yes, it's musical but there is no bass." This comment might be true if the amplifier was made on an insufficient budget with a cheaply built output transformer. The size and consequently weight of the transformer is decisive because it conditions the value of the primary inductance which must be as high as possible. [Interestingly enough, Eduardo de Lima of Audiopax has a different theory and deliberately employs very complex though small transformers in his amps - Ed.] ... The output transformer as a vital part must accordingly be designed at its best, taking into account the finest technology while respecting the rules of the art.
Another challenge is the treble response. Generally, the major problem arises from the dynamic input capacitance (about 50 to 100pF) of the power triode. This requires a preamplifier stage with low output impedance -- practically a power stage -- that is able to deliver current into high frequencies... To obtain this, we have designed an innovative 2-tube input stage in ultralinear mu-follower pentode configuration with a very low output impedance (about 100 ohms) and negligible distortion. This feature is valuable because it does not change the original sound of the output triode through compensation...


During the 70s, Japanese enthusiasts passionate about music and technology rediscovered the qualities of an old Western Electric movie theater amplifier fitted with a single 300B/WE 91A. The amplifier was not perfect but gave surprising musical results. Its dynamics seemed more potent than its modest power rating suggested. Working on the matter by improving the power supply to reduce hum and using a bigger output transformer, our Japanese enthusiasts gave birth to a new range of High Fidelity single-ended tube amplifiers. As we know, technical explanations for their value on the musical results have never been approached. For this reason, I ask the reader to take my conclusions only as assumptions.
First, we have to evoke a specific aspect: the dynamics. Let us suppose that a musical sinusoidal signal modulates the grid of a tube in the positive direction. The plate current will increase to its maximum. This current flowing in the output transformer's primary creates maximum instantaneous voltage at the secondary corresponding to maximum instantaneous power. When the signal modulates the tube grid in the negative direction, the plate current will decrease and break when the grid is at the cut-off point. The current inside the primary of the output transformer then goes to zero. At the secondary, we recover maximum instantaneous power but no more current.
Where is this power coming from? Of course there is the Lenz law which operates by providing an opposing magnetic field to the disappearance of the current. This works well as
the primary inductance of the output transformer is high enough to store this energy. That is the fundamental importance of a generously sized output transformer if we wish to insure good reproduction of low frequencies. The energy stored in the primary is:

For example, in a 300B stage, the idle current is generally 75mA when a good transformer has a 20 Henry primary inductance. In this case :

Let us calculate the distribution of this power according to the frequency we have to reproduce: At 20Hz the time necessary for the inductance to release energy is 0,025 seconds. During this time, the inductance is able to generate a power of :

It is not much and explains the fall of power in the bass. At 100Hz, the time of return is 0,005 seconds. The available corresponding power is:

This power is widely appropriate and the response at 100Hz is practically perfect. The same calculation for the frequency 1000Hz now reveals why single-ended triode amplifiers have such amazing musical power reserves. At 1000Hz, the time of restitution is 0,005 seconds. That gives a disposable power of:

Here we ought to compare what happens in a push/pull amplifier. The electrical storage in the primary of their output transformers is always non-existent. Therefore the profitable phenomenon described above is not present. In the future, I will comment about the reserves mentioned in this technical note. My assumptions are not yet confirmed by well-know scientific studies and I am awaiting the confirmation of a mathematician."

Lance A. aka inmate Chopper87 had already taken the very amp through its paces that would become my review loaner. "Well, the JC further solidified my love affair with the 45, in this case a pair of just run-in Emission Labs solid-plate 45s. This amp has a rounder and fuller presentation in the bass when compared with my Yamamoto A-08S - not necessarily better, just different. The JC also has a really natural bloom in the midrange that is similar to what the Wavelength Audio Geminis offered. This amplifier does wonders with male and female vocals. The highs were a tad bit smoother and delicate than my Yamamoto when driving my Lowther DX-4/Medallion III horns. This amplifier has a very refined overall presentation that made it easy to listen to for hours on end (which I did). The soundstaging of this unit was also huge and billowing and reminded me very much of the modified Antique Sound Labs AQ1006DT 845 SET pair that I wish I'd never sold. The ASLs just sounded so big and meaty and seemed to blow the front of my listening room out into the yard. I would not say that the little JC went that far but it was pretty cool. All of my favorable comments about the J.C. Verdier convertible 45 SET amplifier are in the AC filament-heating mode. I felt that the DC-heated filament thinned out this unit's presentation enough to make a prolonged listening comparison between AC and DC filament heating unnecessary. I didn't care for the amp when DC-heated. I am under the impression that this amplifier was designed for AC filament heating and merely modified for additional DC filament heating capability. It was most likely optimized from inception as an AC-heated amplifier - and it shows.


These two amps (JC and Yamamoto) sound more similar than other 45 SETs I have listened to. For example, the JC is a closer match with the A-08S than the Wavelength Geminis were. The JC offers a bit more prodigious bass when compared with the DC-heated Yamamoto but the A-08S still has more life and magic in the presence region. This was most noticeable on vocals which are a bit more reticent, softer and less defined on the Verdier when compared with the Yamamoto. Some may feel that the A-08S is too forward and hot in this area and I would not completely disagree. On the other hand, Lowther DX-4s are tougher to tame in this area than almost any other speaker that I can think of. Then there is that huge, billowing, 845-like soundstaging of the J.C. Verdier. After my first full comparative listening session, I would have chosen the Yamamoto as my amplifier of choice by a slim margin. I always find myself easily distracted and often enamored by what a new product does differently than what I am used to. The time between the first and second comparative evaluation session almost always gives me clarity to internalize what the new equipment does the same and differently. I can then sit back and feel which product brings me closer to imagining reality in my listening room.


As great as the JC sounds, it just does not quite cross that invisible line that allows me to suspend disbelief the way that the Yamamoto does. With the JC, everything is there. Great, really great lows, detailed and delicate mids and highs and a monstrous soundstage. It also has that typical 45 clarity, just not as much of that difficult to explain 'something is really happening in front of me' as the Yamamoto does. Both amplifiers sound fantastic through every layer of their sonic skin. As I peeled back each layer, the JC and the Yamamoto actually sounded quite similar, both better in my opinion than the Wavelength PF Geminis I owned previously. Then there is that intangible quality or layer that injects the Yamamoto with a life that eludes both the J.C. Verdier and the Geminis. But the J.C. Verdier is a remarkable sounding amplifier, even more so at its selling price of $2,500."