Finally worked up the courage to build the power supply from the schematic (first time for me to build from a schematic) Steve Brown designed for me. The HV is a CLC to a tube rectifier, the filaments a full-wave bridge with voltage divider. Almost done, just have to wire up the CRC smoother after the bridge. The 4Pis should really sing with the added gain from my 2 watt 45 amp.![](http://i415.photobucket.com/albums/pp237/wsepstein/Aikido%20Pre-Amp/IMG_0737.jpg)
Check the middle switch at the rear: it enables switching between a Russian K-40 .22uF PIO, a 2.2uF Obbligato or both in parallel for the output. A cap shoot-out with the turn of a dial!
I just had to sneek a peek at all those 6SN7s. I don't know if I'll use the 5R4 rectifier but it looks cooler than the little 5AR4 spec'd...
![](http://i415.photobucket.com/albums/pp237/wsepstein/Aikido%20Pre-Amp/IMG_0738_1.jpg)
Stay tuned.