This is a single ended 6N1P/EL84 (SV83, 6P15) integrated amp with the EL84(6P15) tubes configured in triode mode. I built this about a year ago and really enjoyed to it in my Den on some DIY single driver speakers for several months and even on my Altec 846A Valencia speakers in my larger listening room. It uses a 5U4GB tube rectifier and the design is very similar to the Decware Zen triode amp with sub chassis mounted output transformers. I've built a few EL84 triode amps and always liked the Decware Zen design, but being familar with the tube, felt the operating point for the 6N1P didn't really do it justice. That is, that tube really likes a good amount of current through it to really open up. At around 10ma of bias current, it now has a nice full bodied midrange with voices having more weight and overall just a smoother balance and broader, more fleshed out soundstage. It is quite simply an outstanding sounding amp. I've owned 45, 2A3 and 300B single ended amps and while I'll admit it may give up a little in absolute refinement compared to NOS tubes in those amps, it truly is only a little, which those of us who have spent too much on those tubes (ahem...like me) are loathe to admit.
I used made in the USA Edcor output transformers with a 6 ohm secondary tap and the closest thing they offered to the primary of the Zen amps. This amp will work equally well with 4 or 8 ohm speakers and like the Zen will put out more power with lower impedance loads. It is about as quiet of an amp as you'll find with AC heaters and is silent at idle on my 96db Valencias.
The amp also features NOS USA made West-cap, paper in oil coupling caps and has the Hazen grid mod, which I felt was a simple but noticeable improvement. The signal path is very short and uses a star single point grounding arrangement. All wiring was done with lead free 3% silver solder and all signal wire is teflon jacketed silver clad copper. The power transformer is over built and stays cool relative to the Zen transformer and comes from a vintage console amp that was far more demanding than this little amp.
I put a metal bottom on the amp with vent holes to prevent fingers from coming into contact with the high voltages within (not shown on any photos) and it has hard rubber feet that elevate it a little for ventilation as well as aid in vibration damping.
The amp will come with the tubes shown which are Soviet 6N1P and 6P15(SV83) military tubes and a used but like new 5U4GB rectifier. The signal and output tubes have about 20 hours on them. The output tubes can be substituted with EL84 tubes and the signal section works well with a 6922 tube. I realize they show the 6N1P as being a 6DJ8 substitute on ebay, but it really is much closer to the 6922 and I would only recommend it as a substitute in this amp.
I might consider trades for the right pair of high efficiency speakers, but monetary remuneration will be given preference.
The rating of 7 is for the DIY hand built nature of the amp and the pictures show any flaws nicely. The buyer pays shipping and paypal fees.