Hi guys,
that is my 12B4A se amp. I build this amp with the goal to give me 1,5 watts pure triode power. It was meant to be connected to my TV, that is why I call it my TV amp. It turned out very good to my surprise. The opts used are pseudo opts, actually from a 100 volt speaker system, but I reverse engineered them to find out the impedance, and they have 6,2 k primary on the longest taps, the other taps are 3,4 k and 2,8 k, but for the 12B4A, the 6,2k tap seems to be perfect. (All that applies for 8 ohm) It sounds and scopes very good, those little opts rock, s long as you don't draw too much power from them. I am not in possession of this amp anymore, someone borrowed it and never returned it. But I will build another one just like it, cause this one did sound rather sweet, and I am very picky,not all triodes I like, some of them sound dull to me. Here are some pics and the schematic as used. After playing with NFB for a while, this amp is one without any feedback, it is stable as is. well, here are some pics.
