Recently after reading a very favorable review of a tube amplifier on Six Moons I discovered that the tube amplifier manufacturer was about to release a transformer coupled headphone amplifier for under $900. The company is Trafomatic, a home audio, industrial, medical equipment and transformer manufacturer located in Mladenovac, in the Republic of Serbia.
Trafomatic manufactures their own transformers, as well as for Korato audio tube amplifiers. The fact that they manufacture their own transformers, their transformers have a good reputation, I could purchase a well designed transformer coupled tube headphone amplifier for under $900 AND the fact that the Head One model has an adjustment feature to tailor the output to accommodate a wide range of phones, that made the decision easy. So I took the leap and purchased their Head One amplifier.
The Head One is a transformer coupled amplifier employing two Russian 6S45P-E triode tubes and one EZ80 as the rectifier tube. The tubes run at 18-20mA and are matched for gain (per Trafomatic). Some brief research confirms that these tubes running at this level would ensure reasonably long life and maximum performance.
The Head One uses an Alps pot, Rubycon and Capxon(sp?) for electrolytics, with a "Cathode bypass, has an electrolytic plus WMA MKC polycarbonate resistor that is a great match. Tube rectification with input L filter plus CLC filter for the anode supply"
As stated earlier, one useful feature on the Head One is the front panel dial for 30,100,300 ohm signal to better match the needs of a different cans. One difficulty I have personally experienced over the years was locating amps that work well with my W1000 cans. For cans with 40 ohm sensitivity of the W1000s, Trafomatic recommended the 30 ohm setting. When I inquired as to how the different output values for various headphones was accomplished, Trafomatic stated that the output transformer was wound with multiple taps to allow for different settings (30,100,300) and that great care was taken to minimize negative effects but they didn't elaborate exactly how that was accomplished.
I chose CDs that I have listened to quite extensively and am familiar with all of their subtle nuances. All CDs have very good sonic qualities and each emphasizes a certain portion of the musical range while highlighting the strengths and weaknesses of the equipment down stream. As source I use a modded Onix X99 with the Superclock upgrade feeding a PreSonus Central Station DAC and for cans my ATH W1000s. Cables were Enigma Audio silver cable Eichman plugs.
The selected CDs were Tord Gustavsen Trio, The Ground (ECM) for the detail and texture of acoustic jazz. A good system can separate each instrument in it's own space while the trio is playing. The decay of the piano notes and the absolute quiet background can be quite revealing in a good system. On tracks one and eight there is some cymbal work where the initial strike and exceptionally long decay of the notes reveals the capabilities in a very good system.
Next is Mater Magnificat (ECM). The strings and chorale passages again require a fast and detailed presentation; there can be no middle ground on this recording. The female voice is very difficult to reproduce accurately and with realism in my opinion and Eva Bittova gives a beautiful and challenging presentation here. The Bratislava Conservatory Choir leaps out at you as a group of individual voices not a mash of music.
Sonny Rollins, Saxophone Collosus, a vinyl rip presenting great detail and headroom on Sonny's tenor sax, the detail of Tommy Flanagan's piano and Max Roach's drums. I chose this CD because in theory a digital copy sourced from audiophile 45rpm vinyl should have a large stage with tons of headroom, and I was not disappointed. The quartet's music seemed to originate from many directions both as source and reflections in a close microphone studio setting. Not the most textured vinyl recording but still very organic and lively in my opinion.
Brian Bromberg, Wood. The album name says it all. Wood is what he plays and what you hear. This bass recording has great detail and if you have had any experience with live string instruments close up such as a viola or upright bass, you will know what I mean. The detail of notes both projecting and resonating in his bass and the long decay of notes on his passages are superb and very precise. A weak system will have the bass notes bloat and roll off noticeably.
In closing I feel the Trafomatic Head One is very detailed and transparent while adding no coloration to the music. The better your source the more of what is in the music you will hear. The sound stage is large, not the largest I have heard but very large and three dimensional. I am not familiar with these odd Russian tubes but they are a very nice musical match to the Trafomatic wound transformer.