Changing 12ax7 tubes for 12at7 tubes on a phono preamp with too much Preamp phono 12at7 12ax7 tube riaa amplifier zero zone schematic mm hifi gain tubes turntable changing too much finished shipping 12ax7 12au7 preamp amplifier preamplifier circuits tubed guitar schematics pedal diyaudioprojects 6sl7 cathode
StompBoXed - The Guitar Pedal Builders Repository: 12AU7 Tube / Tubed
