Musicman 2100-65 Sixty Fve restoration


A friend dropped off an amp head for me. This is the model with an ECC83 in phase shifter. The amp dates from 1973-74.
The fuse blows. The power supply capacitors are original. An EL34 is rinsed. The transformers are not cut, The zeners are heated well.

After research, in addition to changing the 100uF 450V and 20uF 450v capacitors, I was thinking of changing the diodes and resistors of the power supply (low voltage and high).

zener by 5W, diodes on the el34 anodes by THT (4000v) + capacitors (MLCC, Through-hole, 1.5nF, 2kV dc, ±10%, dielectric: X7R)

I am giving you 2 diagrams because the one that interests us is illegible while the other is close (2475-130) and... more readable!

If you know these amps and/or if I make a mistake (with the 5W zener instead of 1W for example), please tell me.


  • 2475 130 preamp.png
    2475 130 preamp.png
    239.6 KB · Views: 51
  • 2475-130 power amp.png
    2475-130 power amp.png
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  • 2100 65.png
    2100 65.png
    315.7 KB · Views: 50