Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ConnorRMoore99 on May 02, 2021, 10:28:10 am
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How’s it going y’all! I’m working on a 79’ Silverface Vibrolux Reverb for a buddy with the goal of making it a gig-ready amp and I have about 1 hair left to pull out trying to figure out this issue with oscillation on the vibrato channel. It had been sitting since the early 90s so it was very dirty but otherwise untouched. Here’s the work I’ve done on it: replaced all electrolytics, all coupling caps, resistors that have strayed in values, screen resistors and power tube grid stoppers, tremolo ceramics, all bias board components, added adjustable bias, cleaned all pots, cleaned/retentioned all tube sockets, and wired in new heater wires with respect to phase and cleaned up the lead dress on preamp tube sockets. Noise floor Channel 1 is pretty darn low and sounds great, but on channel 2 I have volume bleed at 0 and both motorboating and screeching when adjusting volume/tone controls. I’ve made a clip it’s current status so hopefully someone in the sea of knowledge can enlighten me on what this thing is doing! Thanks!
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Welcome. :icon_biggrin:
1. Was the amp working before you did all that work on it?
2. Did the problem start after the work you did on it?
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There are lots of new wiring on this amp. Issue could come from a bad wiring dress