WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Just updating everyone...I built a Boozhound clone, with a little poked PSU. Turns out really well! Breaking it in to some Madonna on some bargain-basement Sharp speakers, but initial audio is very promising.
Can't wait to build some enclosures for my Rainbows.
I can't tell you what efficiency the Sharp speakers I'm using at the moment are (****!!!) but it's certainly not 92dB. And it's already over-comfortably loud.