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63 Fender Twin, snap crackle pop
When I power the amp up and on Standby, when I hit the Standby switch off, it crackles and pops for about 10 seconds, then it quiets down. As it warms up it sounds like static or a crackle is building in the vibrato. There are small pops and it continues to build and eventually there is a loud POP and the noise goes away. It then starts to build all over again and repeats the process. If it shut the power switch off, it crackles and pops as the volume continues to fade to nothing.
If I pull the 2nd pre-amp tube over from the power tubes (not sure of actual number), and power the amp on it is dead quiet when I take it out of Standby. This only allows the normal channel inputs to work though, but it sounds perfect. If I power it off, it shuts down perfectly quiet. If I put the tube back in, it brings back the snap crackle pop.
I recently had to restore this amp. It had been spray painted black in the late 60's, grille cloth was in shreds, speakers were blown, and the power tranny was dead when my Dad got the amp in 1975. He got it working, but it always had the snap crackle and pop really badly, so we more or less moved on from it and it sat in garages and barns until last year. I cleaned the rats nests out of the speakers and cleaned it up. I had to retolex it since there were holes in it and painted black and in shreds, new grille cloth, new dog bone handle. My Dad and I put new Jensens in it, a new replacement power tranny, pre-amp tube sockets, electrolytic caps, coupling caps, the intensity pot was frozen and it had to be replaced -all the others freed-up and work fine now. I only replaced 2 of the plate resistors so far.
I believe our next step is to start replacing the resistors tying into the tube socket holding the tube that I can remove and stop the noises. Maybe we can find it on the oscilloscope this weekend too. My Dad did TV/Radio repair in the 70's. I think he is doing good with all the soldering and troubleshooting, but he doesn't think so.
The amp definitely is better sounding now after replacing the components that we did. The snap crackle and pop that is left, is a lot cleaner than it used to be. It was so bad before that the amp was annoying to play. That is why it sat around for so long without being used.
I will follow up. Please feel free to give suggestions.
Steve
When I power the amp up and on Standby, when I hit the Standby switch off, it crackles and pops for about 10 seconds, then it quiets down. As it warms up it sounds like static or a crackle is building in the vibrato. There are small pops and it continues to build and eventually there is a loud POP and the noise goes away. It then starts to build all over again and repeats the process. If it shut the power switch off, it crackles and pops as the volume continues to fade to nothing.
If I pull the 2nd pre-amp tube over from the power tubes (not sure of actual number), and power the amp on it is dead quiet when I take it out of Standby. This only allows the normal channel inputs to work though, but it sounds perfect. If I power it off, it shuts down perfectly quiet. If I put the tube back in, it brings back the snap crackle pop.
I recently had to restore this amp. It had been spray painted black in the late 60's, grille cloth was in shreds, speakers were blown, and the power tranny was dead when my Dad got the amp in 1975. He got it working, but it always had the snap crackle and pop really badly, so we more or less moved on from it and it sat in garages and barns until last year. I cleaned the rats nests out of the speakers and cleaned it up. I had to retolex it since there were holes in it and painted black and in shreds, new grille cloth, new dog bone handle. My Dad and I put new Jensens in it, a new replacement power tranny, pre-amp tube sockets, electrolytic caps, coupling caps, the intensity pot was frozen and it had to be replaced -all the others freed-up and work fine now. I only replaced 2 of the plate resistors so far.
I believe our next step is to start replacing the resistors tying into the tube socket holding the tube that I can remove and stop the noises. Maybe we can find it on the oscilloscope this weekend too. My Dad did TV/Radio repair in the 70's. I think he is doing good with all the soldering and troubleshooting, but he doesn't think so.
The amp definitely is better sounding now after replacing the components that we did. The snap crackle and pop that is left, is a lot cleaner than it used to be. It was so bad before that the amp was annoying to play. That is why it sat around for so long without being used.
I will follow up. Please feel free to give suggestions.
Steve
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