Hi everyone.
I recently acquired a Silvertone 1484. I replaced drifted resistor and a tube or two and she's humming along fine now, except I have no reverb or tremolo. I traced the tremolo problem back to the optical device transformer. The reverb is making all kinds of horrible clanging and feedback noises, but nothing related to what I play.
So, here's my question. I just want to play the amp without any on-board effects. Can I remove the 12ax7 (V6) that drives the tremolo, remove the 6cg7 (V5) and play the amp like that? Or will removing those tubes and playing the amp damage it?
Thanks for your input!
Silvertone 1484 Tremolo/Reverb Question
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hossymandias
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Cliff Schecht
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Re: Silvertone 1484 Tremolo/Reverb Question
You'll be fine without those tubes as far as damaging anything is concerned.
The reverb is probably the transformer which I've fixed on quite a few of these old Silvertones. The thin, dinky leads eventually break and there isn't much you can do to stop it. You can circumvent the transformer and tap the reverb off of the drivers cathode but if this is done then you should replace the tank with one that likes being driven from a low impedance source vs. a higher impedance as presented by the transformer. In the end it's just easier to remove the transformer (swapping out one part and 4 leads) and put it a Fender replacement transformer.
The vibrato can be a bad ground or a bad cap. Either will cause the trem to not start. I start by checking for DC where there shouldn't be any and make sure all resistors are OK. Then check voltages against what they should be, that will usually tell you the problem area that needs further investigating. Could also just be a dead/dying tube.
The reverb is probably the transformer which I've fixed on quite a few of these old Silvertones. The thin, dinky leads eventually break and there isn't much you can do to stop it. You can circumvent the transformer and tap the reverb off of the drivers cathode but if this is done then you should replace the tank with one that likes being driven from a low impedance source vs. a higher impedance as presented by the transformer. In the end it's just easier to remove the transformer (swapping out one part and 4 leads) and put it a Fender replacement transformer.
The vibrato can be a bad ground or a bad cap. Either will cause the trem to not start. I start by checking for DC where there shouldn't be any and make sure all resistors are OK. Then check voltages against what they should be, that will usually tell you the problem area that needs further investigating. Could also just be a dead/dying tube.
Cliff Schecht - Circuit P.I.
Re: Silvertone 1484 Tremolo/Reverb Question
A weak 12AX7 may be another problem. A good tube is needed to trigger oscillation. If there is nothing but tremolo on that tube, you can buy a cheap Sovtek.