Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: gfarina55 on February 21, 2022, 09:03:25 pm
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I have a Kendrick version of a 6G15 stand-alone reverb that I've been using about 3 hours a day for a couple years, and it's recently developed a confounding issue. When I turn it on, the reverb is very high w/the mix and dwell set at about 1 or 2, and then after about 10-15 min. the reverb all of a sudden gets much lower. Then I turn the mix and/or dwell up to 4 or 5 I get the expected amount of reverb, but after that there is an annoying change in output every few minutes. The sound never disappears, but the output level jumps around every few minutes by itself. The 6G15 doesn't have a volume control, but it's as if the volume jumps from 4 to 6 and back again by itself every few minutes.
I’ve changed all the tubes, tried both inputs, chopsticked and visually inspected the inside. I haven’t cleaned the pots b/c it doesn’t seem like a pot issue. (When I turn them they always work as expected.) It’s also not the input jacks b/c it does the same thing on both inputs.
Has anyone encountered this issue w/a 6G15? Any advice for next steps? I could check the voltages but I’m not sure what to look for.
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have you tried replacing the pan send-return cables?
Have you monitored the voltages when the reverb level change occurs?
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have you tried replacing the pan send-return cables?
Have you monitored the voltages when the reverb level change occurs?
Thx, I'll try the pan/cables. Not sure how to monitor the voltages when it happens b/c I can only tell it's happening when I'm playing.
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..." The sound never disappears, but the output level jumps around every few minutes by itself."
gfarina55
Bad solder or contacts ?
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..." The sound never disappears, but the output level jumps around every few minutes by itself."
gfarina55
Bad solder or contacts ?
Yeah, that's what I thought but I chopsticked the heck out of it. Every solder joint seems solid, and I can't get any components to make noise when I poke them.
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have you tried replacing the pan send-return cables?
Have you monitored the voltages when the reverb level change occurs?
Thx, I'll try the pan/cables. Not sure how to monitor the voltages when it happens b/c I can only tell it's happening when I'm playing.
test clips
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..." The sound never disappears, but the output level jumps around every few minutes by itself."
gfarina55
Bad solder or contacts ?
Yeah, that's what I thought but I chopsticked the heck out of it. Every solder joint seems solid, and I can't get any components to make noise when I poke them.
I never use chopstick, most of the time it's not working for me. Reheat solders.
Solder look solid ! You may have aliems eyes........... :laugh: