Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rustyadams on August 15, 2024, 01:50:18 pm
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Help! Tremolo is not working. I replaced the opto coupler (roach) and still nothing.
I have swapped tubes V1 with V5 no change. Could bad capacitors cause this to no longer work?
I've attached the schematic for this circuit. Any suggestions?
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how close are V5s VDC readings to those on the schematic?
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Oops was thinking reverb LOL ok have you tried a footswitch?
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using a digital voltmeter V5 voltages : Pin 1 275-284 VDC Pin 6 : just flashing OL not getting a reading
Have checked out the footswitch and it is good, also tried another cable with leads shorter just to be sure
Does tremolo rely on the reverb tank? I have the reverb with the red dot going into the reverb input
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sorry Rusty read my post again.. old person here.. sorry I've never seen the tremolo capacitors go bad
what model twin is it? probably doesn't matter concerning the trem circuit here's schematic for 100w twin https://el34world.com/charts/Schematics/files/Fender/Fender_twin_reverb_sf_100_schem.pdf
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the oscillator caps can be problematic, how many tubes have you rolled through? Trem needs a solid tube
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using a digital voltmeter V5 voltages : Pin 1 275-284 VDC Pin 6 : just flashing OL not getting a reading
How about the cathodes?
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not good... cathodes are at 0 V
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That means a short. Lift the caps and remeasure. The trem won't work, but it'll rule them out.
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Thanks for all the replies. I had a 12AX7 from another amp, I replaced it with that and it works. Noticed that the tube that was in there is a ECC83S.. not sure if that is the same as a 12AX7.
Anyway I took out the 12AX7 and put the original ECC83S back in. And it works! Could it be dirty contacts in the socket? should I replace socket or try to clean it?
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clean it