The amplifier circuit itself is simple – a few discrete components surround the LM3886 and it’s heat sink. [Ynze] also did some very nice carpentry work on his wood chassis. The resulting amp ...

[Mikremk] demonstrates this with a simple but effective amplifier using a PCL82 triode-pentode. It’s a conventional tube amplifier circuit in which the triode is a preamplifier for the pentode ...

After a brief review of the history of the K2-W vacuum-tube op amp, an LTspice model is used to create its schematic in ...