Troubleshooting and Testing Frustration

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JMPGuitars
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Troubleshooting and Testing Frustration

Postby JMPGuitars » Wed 07/10/19 1:58 pm

You ever chase a noise that evades you forever, and it winds up being something stupid? I'm sure you have. ;)

I posted a while ago, about how a power supply in a different room in my house was causing an oscillation. I didn't know that at the time, so I chopsticked like crazy, and eventually figured it out by a stroke of luck.

Well, since then I've been sure to keep that thing unplugged while troubleshooting. One of my prototype amps I've been working on sounded awesome, but I had a stupid oscillation showing up, and I couldn't get rid of it. This went on for a while. Whenever I had spare time, I would work on it. Chopsticking, changing lead paths, etc...

I chopsticked the thing so much, I wound up needing to replace two of the preamp tube sockets! Poor bastages couldn't handle all the wire flopping and fussing. Oops.

I got the thing so quiet it was crazy, but the stupid oscillation persisted. Out of sheer frustration, I reached over and shut off the power strip that has all my networking/wifi stuff on it. Poof! The noise was gone, the amp was dead quiet.

Once again I learned the hard way to eliminate outside influence...but on the bright side, if I can make an amp quiet with that interference 3 feet from my desk before I shut that stuff off, the final product will be killer.
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zuceno
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Re: Troubleshooting and Testing Frustration

Postby zuceno » Thu 07/11/19 8:32 am

I have an old AM pocket transistor radio which also serves to detect noisy equipment in my environment. So much of the noise around me is due to computer equipment, and the associated wall wart power supplies.

The radio can even tell me if the neighbours are using their microwave!
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Re: Troubleshooting and Testing Frustration

Postby Returnsnull » Thu 07/11/19 9:16 am

I had a horrible squeal that I couldn’t isolate and that also seemed to come and go randomly.

Well, it turns out that I had my output cable touching and running parallel with my input cable. I figured that out by accident after spending about a week and a half doing unnecessary work.
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Re: Troubleshooting and Testing Frustration

Postby JMPGuitars » Thu 07/11/19 11:04 am

zuceno wrote:
Thu 07/11/19 8:32 am
The radio can even tell me if the neighbours are using their microwave!
lol Yeah, but can it tell you what they're cooking?
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Re: Troubleshooting and Testing Frustration

Postby crgfrench » Fri 07/12/19 12:52 am

Thought you were having a bad day? feel better -- I just dropped a G12M from about 2' onto a pine floor and now it's no longer truly round.
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Re: Troubleshooting and Testing Frustration

Postby JMPGuitars » Fri 07/12/19 10:50 am

Delete that message and tell them it happened in shipping. ;)
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Re: Troubleshooting and Testing Frustration

Postby colossal » Fri 07/12/19 7:28 pm

crgfrench wrote:
Fri 07/12/19 12:52 am
Thought you were having a bad day? feel better -- I just dropped a G12M from about 2' onto a pine floor and now it's no longer truly round.
Oh no! :o :| :x Hopefully it was a reissue!
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Re: Troubleshooting and Testing Frustration

Postby colossal » Fri 07/12/19 9:07 pm

JMPGuitars wrote:
Fri 07/12/19 10:50 am
Delete that message and tell them it happened in shipping. ;)
:lol:
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