This is power amplifier OTL circuit,It is old but good amp(classic) I like it.
It is have power output 60W at 8ohm speaker.
I use IC op-amp LM3900 is mian part in this circuit.
The LM3900 function amp audio signal,ad have transistor 2N3055 x3 for boost power sound audio.
The voltage power used 70V at 3A min.
