Valvestate Problems, no sound, popping, etc..

gsgtrman

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Hello everyone, I have two Valvestate amps that I use for lessons. The first, an 8240, is mostly ok... I replaced scratchy pots recently and that is fine. While I was in there I found two connections to the rocker power switch were not solidly soldered and loose. I resoldered and checked the connections and the amp is functioning as it should. But there is a pop every time I power it up. It doesn't happen at all otherwise. Any ideas are appreciated.

The second amp is an 8020 that just suddenly stopped working. Now it gets signal but loud static in the normal channel, and no signal in the boost channel, except for pops when I turn the volume knob. I went over the circuit board and all electrolytic caps look fine, no signs of anything else going south. It's a cheap amp and I don't want to put any real money or time into, but if there is a simple fix maybe I can get a few more years out of it. Again, any ideas are appreciated.
 

KraftyBob

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Was the popping noise in the 8240 there before you re-soldered the power switch? Loud popping is common when powering off solid state amps, but I'm wondering if something is going in with the switch if it pops when powering on?

Try replacing the tube in the 8020 for starters. If you don't have an extra 12AX7 on hand, temporarily swap it with the 8240 and see if that makes a difference.

Report back.
 

gsgtrman

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Was the popping noise in the 8240 there before you re-soldered the power switch? Loud popping is common when powering off solid state amps, but I'm wondering if something is going in with the switch if it pops when powering on?

Try replacing the tube in the 8020 for starters. If you don't have an extra 12AX7 on hand, temporarily swap it with the 8240 and see if that makes a difference.

Report back.
Thanks for getting back to me. The popping was not there before I resoldered the switch. Also the 8020 is one of the models that is completely solid state, no preamp tube.
 

KraftyBob

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Maybe re-check the soldering on the switch since it wasn't there before.

I was not aware that there was a Valvestate amp that doesn't have a valve in it lol. Anyhow, since everything visually checks out (caps and resistors) it could possibly be an OpAmp, etc. At this point a signal trace would be helpful to find out where it's failing but you need and signal generator, dummy load and oscilloscope for that.
 


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