No volume control on this one.

First order of business was to get the right power transformer. I decided to have one made from Edcor. Because of the setup fee, I went ahead and ordered two. This transformer is strong enough to power a single SE stereo 2A3 or 300b or one push pull mono-block. The tranny has more voltage than is typically needed for a 2A3 amp, but that was planned to accomodate the PP version as well. So for the SE version I use two cathode bias resistors and tap the grid into it. Now I have a suitably high voltage to make the most I can out of the input/driver tube.I also pick up the benefit of needing a smaller cathode bypass cap, putting the value well within the range of a decent MKP type.

Orignally I planned on trying a 6CJ7 in triode mode. This actually worked out quite well. The EF184 and D3a also plug in without changes if desired, although some small optimizationa can be made. Ultimately, the EF184 won the battle with both the suppressor and the screen tied to the plate.

Of course, an SE amp is only as good as its output transformer. On a cost for the bang basis, it is pretty hard to beat the One-Electron UBT series. Since I favor a 3K load for the 2A3 anyway, I decided to try them out and I wasn't disappointed.

Notice the simple layout all this planning achieves. There are no electrolytics in the power supply or anywhere in the signal path thanks mainly to the large black film filters I scored for a fair price. It's nice to et a fair price once in a while.

The sonics of this amp are excellent. Very wide bandwidth, excellent low impedance drive to the 2A3 grid and lack of electros goes a long way. As a bonus, swapping out the 5AR4 rectifier with a 5R4 type lowers the operating voltages and nudges the Sovtek into Heaven. With some minor changes, this configuration will also run a 45 tube.