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Vintage threads from the first ten years
| previous: Phil H Just bought 1963 Bandmaster, played... -- 7/8/2000 5:16 AM |  |
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Re: Bad smell volume loss in Bandmaster
 7/8/2000 2:11 PM |
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R.G. | Re: Bad smell volume loss in Bandmaster
That "bad electrical smell" is the gentle odor of components going screaming into whatever serves for a component afterlife. What most likely happened was that the amp went into ultrasonic oscillation and fried some things. The real question here is, of course, what fried and how to fix it. First - is the volume loss permanent? Does the volume stay low now, with speakers attached? If not, you may just have fried some transformer varnish or component paint. If yes... , well, it's gonna need some work. Especially if the electrical smell gets worse again if you operate it with speakers connected now. Let's assume the volume loss is permanent. (1) have you read the Tube Amp Debugging Page at GEO? That pages synopsizes more than anyone can type about debugging an amp, and the recommendations about what to do here will come from writing that page. First - try replacing tubes. You could have arced and output tube, and this may fix it. (2)If replacing tubes doesn't fix it, the repair process will require messing around and reading voltages inside the amp with power on. Take a long, serious look at the safety cautions on the Tube Amp Debugging Page and decide how much you're betting your life that you can poke around in there without dying. If there's any question, go for a repair tech, in spite of difficulty and expense. You'd pay a lot more to avoid medical or funeral expenses, I think. (3)If you find you want to take the responsibility for your safety, get a volt-ohm-meter and start through the debugging process on the page. That will almost certainly find what was damaged. It is likely that you have scorched screen resistors (good, not very expensive) or output transformer (bad...). You'll wind up measuring the B+ and other tube voltages and checking the output transformer for shorted (test setup also at GEO). Also some other tests. If you get stuck, post back here or write me. | |
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| Replies: |
| Brad This may sound obvious, but the fir... -- 7/8/2000 3:12 PM Richie These are good replies.. i'd also c... -- 7/8/2000 5:45 PM Phil H Firstly, all responce from me will ... -- 7/9/2000 12:22 AM |