1975 Fender Princeton Reverb

I have many of these Silver-Panel Fender Princeton Reverb’s on this site - they may be the most popular and common amp I get in for restorations. The Fender Twin Reverb from the same era comes a close second. These are fantastic sounding amps and they never get old to listen to. By this many years after production they all have a unique character that only a vintage amp can attain.

The amp was completely restored. The electrolytic cap can was replaced with a new USA made CE brand exact replica for the filter section. The bias circuit and bypass caps were replaced with a 1N4007 1000v Diode and MOD brand electrolytics with upgraded voltage and temperature ratings. New 2 Watt Metal Oxide/5 Watt Cement power dropping resistors were installed for better reliability and lower noise floor. The same was done for all the preamp plate resistors and some cathode resistors. All of the coupling capacitors were replaced with Mallory 150 630v film type units - the coupling caps present in the amp were almost all replacements and not at the correct voltage ratings. They are also far better quality capacitors for this circuit, they made the amp sound much smoother and gave it some tonal magic. A new 3 prong AC cord was installed to replace the old AC cord and the death cap was removed. The ground switch was also deactivated for safety.

The original tubes (a mix of NOS and new) did not test good and were all replaced. V1 = JJ 12AX7MG, V2 = EHX12AT7, V3 = JJ 12AX7S, V4 = JJ 12AX7MG, V5-V6 = EHX 6V6GT, V7 = EHX 5U4GB. These tubes were picked for best tone and reliability. The 6V6GT’s Fixed Bias was set to %60 Class AB Plate Dissipation with a B+ of 372VDC. The octal tube sockets were all replaced and re-wired to stop the tubes from jiggling or falling out while they hang upside down and because of broken pins internally that were damaged by previous attempts at repair. The pots were sprayed out and the amp was cleaned inside and out. Amp now functions perfectly.