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Reviewer: Srajan Ebaen
Financial Interests: click here
Source: APL NWO 3.0-GO; Ancient Audio Lektor Prime; Raysonic CD-168
Preamp/Integrated: Supratek Cabernet Dual; ModWright LS-36.5/PS 36.5; Wyetech Labs Jade; Almarro A318B; Melody I2A3; APL UA-S1; Woo Audio Model 5; Raysonic SE-20MkII [on review]; Trafomatic Experience One [on loan]

Amp: 2 x Audiosector Patek SE; 2 x First Watt F4; Yamamoto A-08s; Yamamoto A-09s; Fi 2A3 monos
Speakers: Zu Audio Definition Pro; DeVore Fidelity Nines; WLM Grand Viola Monitor with Duo 12; Rethm Saadhana; Zu Presence [on review]; Mark & Daniel Maximus & Ruby Monitors w. OmniHarmonizer

Cables: Ocellia Silver Signature loom; Crystal Cable Ultra loom; Zanden Audio proprietary I²S cable; Crystal Cable Reference power cords; double cryo'd Acrolink with Furutech UK plug between wall and transformer; Stealth Audio Indra and Meta Carbon
Stands: 2 x Grand Prix Audio Monaco Modular 4-tier
Powerline conditioning: 2 x Walker Audio Velocitor S fed from custom AudioSector 1.5KV Plitron step-down transformer with balanced power output option; Furutech RTP-6 on 240V line feed
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio Vivid CD cleaner; Walker Audio Reference HDLs; Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro; Acoustic System Resonators and front wall sugar cube matrix
Room size: 16' w x 21' d x 9' h in short-wall setup, with openly adjoining 15' x 35' living room

Review Component Retail: € 8,900/pr + freight

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Trafomatic on the rampage.
That header does quite conjure up serial killer exploitation flicks and gratuitous carnage. Here though excess and gratuity become eminently more laudable: charged productivity for plenty of fair-priced stuff. No sooner did this Serbian transformer specialist launch its overachieving The Experience One 2A3 integrated (€1,870 in Finland, $2,060 in US) than a dedicated valve headphone amp followed ($870). Then a transformer-coupled powerline conditioner in 500 ($690), 1000 ($950) and 3000VA ($1,690) sizes. Then a 300B integrated ($2,950). Then a valve phono stage. Then a remote-controlled valve preamp. Phew. Mind you, all this from a newly minted company that was non-existent as an electronics manufacturer just one year prior. So perhaps 'gangbusters' would have been fittinger than 'rampage' but the message stands and made its point. Did you do the numbers? These folks are just one model shy of seven - as in, seven wonders of the world. Or seven deadly sins (to which the Pope recently added more if you require variety on that count).

While 6moons won't be looking for a seventh moon soon, the R&D team under chief Sasa Cokic at Trafomatic has promptly cooked up "true reference amplifiers all around". Those hit that magickal number seven - in case there's something to such numerology. These statements are a pair of interstage transformer-coupled, parallel single-ended 300B monos for 15 watts of class A power. Conceptually, think $7,800/pr Wyetech Labs Sapphires, a design that netted a Blue Moon award from us and a Golden Ear from The Abso!ute Sound. Unlike the Sapphires, the Trafomatix don't run 5687 drivers. They get JJ ECC99s, tubes specifically developed as 300B drivers. The Serbian monos also get Trafomatic's new toroidal filter chokes, dual-C core output transformers weighing 10 kilos each, WBT connectors, a black piano finish with gold transformer cases and twin tube rectifiers (1 x 5U4G and 1 x EZ81).
As bona fide transformer experts who roll their own for each project -- the electronics division adds 'Audio' as a subsidiary of the decade-old transformer company -- Trafomatic is perfectly positioned to go to iron town and come back with pure gold. I was impressed enough with Theo (my nickname for The Experience One) to affix a rare Realsization Award. How far would these crafty Serbians push a no-holds reference concept to make their big mark on the international hifi scene?

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2008, I have you know, is becoming my Year Of The 300B (audiophiles need their own Chinese horoscope). In March, I added Woo Audio's two-piece headphone/speaker integrated to my amp stable. I wanted to listen to some of my current production Western Electric bottles over audio-technica W1000s and AKG K-1000 headphones. Even prior, I had ordered the new A-09S reference amplifier from Shigeki Yamamoto to get my name on the first production run. This amp would allow testing of even EML and KR high-current 320-style XLS glass. When Raysonic solicited me next for one of their new MkII integrateds, I naturally picked the SE-20 MkII for its 300Bs and to really grab the emerging theme by its shorthairs. While those three amp designs are non-paralleled for single-digit power, my speaker harem has been deliberately assembled to mostly sing on... well, 2 mighty watts of direct-heated 45 octane juice. This might redress what otherwise could be lopsided comparisons on raw power. The 15-watt Trafomatic Audio twins would thus woo or woe the Woo; jam or Lord of Death Yama with the Yamamoto; and rayce against or get rayned on by the Raysonic for some good-natured audio Olympics.

The Magnificent Seventh?
The Experience One
in black and gold trim shows where Trafomatic has been. The new Reference monos show where they're going. The vital iron on board has been seriously scaled up.

That interstage transformer
Some audio designers -- everyone has their pet peeve -- feel that coupling capacitors between amplification stages exert an undue sonic influence and are best avoided. Then a DC-coupled amp as Frank Blöhbaum has done for Thorens is it. Unless of course you go capital IT. That would be our interstage transformer
which can also be used to split phase in push/pull circuits. Or appear in pure transistor circuits. United States Patent 3927380 describes a two-stage cascaded transistor amplifier in which the stages are transformer-coupled by a 1:20 transformer whose low-impedance winding connects to the output of the first stage and whose high-impedance winding to the input of the second stage. Of course other transistor amp designers diss the phase-shift inducing, slew-rate robbing, bandwidth-curtailing effects which -- they claim -- are caused by "endless coils of transformer wiring".

To map out a terrain familiar to me solely on hearsay, I identified the following, currently available commercial single-ended IT-coupled 300Bs :
  • Mike Morrow's Morrow Audio 300B1S monos - $6,500/pr;
  • Hans-Jürg Dorn's Althea Musica Royale 300B Concept Mono;
  • Sun Audio's SV-300BSM - ¥810,000;
  • SAC Thailand's custom-order WE 300B monos;
  • WAVAC's EC-300B, MD-300B and MD-300Bm - from $8,500 to £16,500;
  • Promitheus Audio 300B monos - $1,500;
  • Audio Note UK Kegon - $49,000;
  • and the Border Patrols with outboard power supplies - €10,600 for the paralleled Model S20.
  • Allnic from South Korea
  • TruLife Audio from Greece, 1000 per watt, interstage transformer bandwidth beyond 2MHz
Sidebar 1: Those who advocate their use will tell us that "in interstage transformer coupling, the impedance level is high to maintain both high load impedance and high grid excitation in the following stage.The limit on the secondary side is the highest resistance which affords grid circuit stability. There is no impedance limit on the primary side except that imposed by transformer design. Usually a 1:1 ratio is about optimum. A step-down ratio gives less voltage on the following grid. A step-up ratio reflects the secondary load into the plate circuit as a lower impedance (from Hans Lohninger's page)." That "the advantage of using this type of transformer in certain applications is that it gives a different type of clipping behavior, the output tube grids can be driven somewhat into the positive range (because of the low DC resistance in the grid circuit), if a low impedance bias supply is used." More evangelical even is AudioNote UK: "It is becoming increasingly obvious that applying transformers at every stage of an amplifier yields a great benefit in sound quality, provided of course the transformer in question is of an appropriate quality and design."... continue
Output transformer winding at Trafomatic

For kits or published DIY circuits with interstage transformers, reference AudioNote UK kits and Lynn Olson's Nutshell HiFi Karna (6H30 or 5687/7044/7119 input, 45 driver). For further 'open' circuits, Nobu Shishido's IT-coupled 300 SE Topology was published in Glass Audio in 1994. For perhaps the most generic non-IT 300B SET circuit, think 3-stage affair running 6SN7 dual-triode input/drivers. Much present Chinese offerings seem to fall into that category. Other designers don't see the need for two voltage amplification stages with their higher complexity and cancellation of harmonics. They favor less stages. The earliest 2-stage circuits used pentode drivers like Western Electric's legendary movie house amps. Shishido used 6L6s. Gordon Rankin's 2-stage Wavelength Cardinal sports a shunt-regulated push-pull stage (SRPP) to drive its power triode. Other 2-stage topologies use single rather than dual triode drivers. Japanese audiomaniacs seem fond of the classic Western Electric 417A/437A drivers when transformer-coupled to the power triode, championed particularly by Shishido and Sakuma. SAC too adopted this recipe for its current flagship monos. Then there's direct-coupling and the Loftin-White approach.

To avoid urban myths on whether capacitor or transformer coupling is ultimately superior, I asked Sasa Cokic why they went IT for their statement efforts. The part's formulation had delayed the amps' launch more than once, with an earlier Cokic e-mail mentioning an eighth iteration of the transformer. This mirrored what the Japanese whispered all along. Only the very finest iron (they favor Tango and Tamura) does this circuit juncture justice. Hence the expense and relative rarity. To get it right is mission critical and more challenging than simply wishing away those coupling caps. Considering how few amplifier designers double as magnetics designers further explains why this subject remains less visited. And why Trafomatic Audio is wonderfully positioned, specializing in transformer manufacture first but now designing electronics to showcase some of those transformers. (The operative term is some. Trafomatic also makes "10KVA monophase transformers for primary and secondary voltages up to 1000V, three-phase transformers from 5KVA to 50KVA and electro-resistance welding transformers from 18KVA to 75KVA".)

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"If we look behind us with the intention of explaining the interaction of basic knowledge and experience in building SE amplifiers, it becomes very obvious that this story in most cases has no predictable results. So sometime it's difficult to give answers to some questions while others can be found in basic theory and recognized technical standards. The reference amplifier was born with many difficulties as it should represent a fusion of technical performance and audiophile requirements. Concept and design are fully in accordance with our philosophy as mentioned in our earlier correspondences for your Experience One review. The two tube rectifiers are a consequence of the higher current consumption in our input stage ( 40-50mA was the designated value) since we wanted very strong driving force for the two paralleled 300Bs. With the small help of an EZ81, we ensure that the 5U4G is loaded below 200mA, important for long life and fault-free operation with minor influence on the final sound.

"With a driver of small input resistance, very big and extremely expensive coupling capacitors become necessary (see Crystal Cap for example). But it's impossible to minimize unwanted effects of grid current in overload conditions where an interstage transformer can offer some advantages. Our job was to use these advantages for maximum performance. In that process, two interstage transformers made by quality producers were tested and gave us good technical results. However, sonics were below our expectations, becoming the main reason to begin this adventure of our own interstage transformer. Of course we don't want to say that our transformer is categorically better than those we tested. Ours was simply designed to best fit our given circuit topology. That's all. Its 1:1 ratio is not unique but offers the desired balance of sound and performance. We experimented also with added gain and ratios below 1 but without significant benefits. This work will be continued in the future and may have some influence on concepts in new products.

"About our choice of driver tube, the ECC99 is a very good valve, one of the best small-signal tubes JJ makes. As you know, it was especially developed to drive 300Bs. It has very good electrical characteristics as well as power. That is very important especially as ours drives two 300Bs. Plus, ECC99s are in current production as are 300Bs - and our location in Europe finally makes JJ also a good choice for proximity."