Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tylerrussell on April 06, 2016, 02:55:57 pm
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...hi, all. Hoping for some advice on where to look for this issue. Home brew 5e3 that's worked very nicely for a year or so with moderate playing time. A few hours per week. It randomly starts Ssshhshhh, pop, Sshhssh. Might not do it at all sometimes. Flipping it into stand-by, then out of stand-by---no more noises or popping. Cleaned all tube sockets, tube pins, input jacks, swapped tubes, touched-up some solder joints.
Is this reason to suspect a wonky component? If so, where might I start? It's my first build and quite ugly inside compared to what I've seen on this forum, but it has been working fine until now. Nothing out of the ordinary in the circuit other than .022's instead of .1's to tame some of the woofiness. Any input is appreciated. Thank you.
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Even though you've mostly done the right things I think you haven't done the soldering touch-ups thorough enough? Start at the input jacks and moving across hitting everything re-flowing a bit more solder on all tube sockets, pots, board, and even filter caps.
If you want to test your troubleshooting skills a bit - but be extremely careful - and using insulated needle nose pliers you can grab each wire near it's soldered point and stress the joint a bit with the amp on and guitar plugged in. If you have a looper pedal, signal generator, or similar it will help to hear a bad joint too.
I recently finished a bunch of modifications on a design during some final tone tweaking and this came out of nowhere - it ended up being the shielded wire from the input jacks when I had to un-solder it for the mods and put it back a little too quickly...
This issue is fairly common and can happen to everyone at some point. I generally use flux on all new contact points/parts that are not tinned first. Or I tin the part or wire first if I don't flux first. Sometimes it takes flux and tinning both - prior to soldering to get a good joint.
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Thanks for that. I have stressed connections with a pointy wooden 1/4" dowel rod while on and plugged in. Didn't get anything to jump out at me though. The goofiest thing is, if put into stand-by for about one second, then flipped back to operating mode it's fine---until the next time it decides to do it. Maybe five minutes, maybe an hour, maybe not at all! :cussing: I'll try more re-flowing the joints. Thank you for your input!
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Yur welcome. Sometimes the wooden stick isn't enough to get the joint going in various directions or stressing it enough to expose it? I can't tell you how many times I've found bad solder joints to be the problem in fixing not just amps (with solder boards) but electronics in general. Just as things that are exposed to outdoor weather conditions, our amps get pretty darn hot and get very cool too if you live in areas like this? The continual expansion and contraction to heat & cold with the many repeated cycles of this helps create these things also. I think your issue and description still fits with what I'm saying and being intermittent with it's characteristics since you eliminated the tubes and likely their contacts too?
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Yeah.....the wire connecting the #8 pins together on the 6V6's seemed to make some noise when agitating them. I replaced that wire 'cause it just looked kind of funky~we'll see how that works out.
Thanks again.