Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: waldner on March 03, 2022, 09:42:57 pm
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This vintage Fender amp is in very good shape, and seems to work perfectly other than one problem. Playing it for awhile with the volume at around 2 or 3, it will suddenly get noticeably louder or quieter on it's own. It has done this several times regardless of the guitar or cables used. When it changes volume, it tends to stay there (louder or quieter) for awhile and then will sometimes switch back again.
Many of the electrolytic caps are original on the main board but I did replace the electrolytic multi-cap can with a new equivalent from CE manufacturing. Other resistors and caps (carbon comps and blue molded) are original but everything seems in very good shape and sounds great in terms of tone and dynamics other than the changing volume issue.
Any thoughts on what could cause this, where to troubleshoot?
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Dirty volume pot or bad volume ground (solder ?) ?
Re heat all 3 volume legs solders
Re heat volume ground(s) solder(s)
Clean volume with good contact cleaner like Deoxit ; spray inside the pot and turn shaft at least 10 times
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Ok, thanks. I will try all of those.
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Might as well clean and lubricate the tone pot while your in there.