Converted this Hammond A0-43 organ amp to a guitar amp with dual KT66/6L6/EL34 outputs. The preamp consists of two 12SL7s, and I wired their (12V) filaments in series and used the heater current to cathode bias the power tubes. "free" and quiet DC heaters and a lot less wiring!
The power transformer is from an old Lowrey organ and the OT is custom from Pacific.
I ended up mounting the chassis in an old Sound City PA cab, but I forgot to photograph it.
