Other DC amplifiers  

   4 or 5 years ago we could get several FET devices at Akihabara, but now
we could get very limited ones. At that time I manifactured many amps, for I
wanted to know their tone character.

Toshiba K1529

 Bright and dynamic tone. This is good for listening to Dave Grusin sound.

Toshiba K405

  Changing bias part of K1529 amp, I listened to the tone of K405.

  This was of cloudy tone. More tuning up was thought to be necessary.

Sony K722

  Sharp tone. This FET was fragile, for it had no protective diode .

Motrola MJ2955

   Driver stage is MOS FET loosely heat-coupled to final stage. This amp
is of good use enough.