Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TwinJunior on June 22, 2022, 11:17:02 am
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The reverb effect on my Fender Twin stopped working. I have checked the connections and examined the tank and everything seems to be in order. The weird thing is when I tap on the tank I can hear the reverb but it's not affecting the guitar signal. The guitar still plays clean but I hear the reverb of my tapping on the tank.
:dontknow:
Any ideas?
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https://ampwares.com/schematics/65_twin_reverb_@20manual.pdf
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Measure resistance of the white reverb cable, pin to pin and shell to shell (should be about zero ohms for each). Then measure resistance between pin and shell (should be infinity, open circuit).
Replace V3. Is filament glowing? (May need to turn off room lights to see)
Check voltages on V3 pins 1, 2, 3, 6, 7, 8. Post voltages, even if zero. Pins 1 and 6 should be about 440vdc. Pins 2 and 7 should be zero. Pins 3 and 8 should be about 8vdc.
If voltages are wrong check resistance between red and blue wires on T1. Also check resistance of R25 (should be 2.2KΩ)
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The weird thing is when I tap on the tank I can hear the reverb but it's not affecting the guitar signal. The guitar still plays clean but I hear the reverb of my tapping on the tank.
:dontknow:
Any ideas?
Reverb Recovery circuit work, not the Send circuit.
You can use any stereo / hi-fi cable to replace original cable if you not sure of the Fender cable.
Clean RCA connectors ; amp side and reverb tank side