Oscilloscope and DMM Suggestions !

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Bieworm
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Re: Oscilloscope and DMM Suggestions !

Post by Bieworm »

JMPGuitars wrote:
Thu 12/24/20 9:20 am
Bieworm wrote:
Thu 12/24/20 4:41 am
I received a gift earlier this week from my wife's uncle.
An ensemble of the same series equipment:
That's awesome.

Maybe you don't need the UTD? Here's a test. Try and get the measurements on screen on the UTD model and see if it gives you the values like I showed in my screenshots above. That's one big area digital scopes are better than any old school stuff. If the UTD doesn't do that well, I'd return it and rely on the old scope until you get a good deal on a digital scope. Check EEVblog like I mentioned above, they might have somebody selling a nice digital scope secondhand close enough to you. If the UTD does do a good job showing those measurements, then it's probably worth keeping if you can't get anything else at a reasonable price.er
It's so frustrating.. I don't know what to look for. I see a curve where the first top of the positive is bumping and then going flat and down. I wish I knew more about that...there is few info about tube amps
I'm looking for oscillation...
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Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

Bieworm wrote:
Thu 12/24/20 12:14 pm
It's so frustrating.. I don't know what to look for. I see a curve where the first top of the positive is bumping and then going flat and down. I wish I knew more about that...there is few info about tube amps
I'm looking for oscillation...
You mean you're trying to find an oscillation in an amp?


Watch some videos:
https://youtu.be/bCN4LH4urns
https://youtu.be/EpsUVc3lcMk
https://youtu.be/mjZjvDYN-Og


https://youtu.be/y6IUecNa4KE
https://youtu.be/xaELqAo4kkQ


D-Lap, Mr. Carlson's Lab, and EEVBlog are all great sources.

Avoid Uncle Doug he's dangerous. Don't follow his advice (unless you and your amp are both shock proof, and immortal).
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Bieworm
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Re: Oscilloscope and DMM Suggestions !

Post by Bieworm »

JMPGuitars wrote:
Thu 12/24/20 1:23 pm
Bieworm wrote:
Thu 12/24/20 12:14 pm
It's so frustrating.. I don't know what to look for. I see a curve where the first top of the positive is bumping and then going flat and down. I wish I knew more about that...there is few info about tube amps
I'm looking for oscillation...
You mean you're trying to find an oscillation in an amp?


Watch some videos:
https://youtu.be/bCN4LH4urns
https://youtu.be/EpsUVc3lcMk
https://youtu.be/mjZjvDYN-Og


https://youtu.be/y6IUecNa4KE
https://youtu.be/xaELqAo4kkQ


D-Lap, Mr. Carlson's Lab, and EEVBlog are all great sources.

Avoid Uncle Doug he's dangerous. Don't follow his advice (unless you and your amp are both shock proof, and immortal).
I'm just trying to comprehend an expand my knowledge... preferably from people with legit knowledge. You have always pointed me in the right direction, so thx for the links. Uncle Doug is funny and entertaining. But that's it. God, I miss rusty
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"THIS should be played at high volume..preferably in a residential area"

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Re: Oscilloscope and DMM Suggestions !

Post by Bieworm »

Josh, is it theoretically possible to get oscillation caused by the isolated IEC plug?
Just wondering...
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Re: Oscilloscope and DMM Suggestions !

Post by JMPGuitars »

Bieworm wrote:
Thu 12/24/20 4:41 pm
Josh, is it theoretically possible to get oscillation caused by the isolated IEC plug?
Just wondering...
Isolated? I think you mean filtered? A filtered IEC inlet should filter out oscillations, not cause them.

Test your electricity source for oscillations. You could be picking up something else even with the filtered inlet. After confirming that the oscillation isn't coming from outside the amp, then test the amp systematically. Chopsticking/moving wires, tapping caps, etc...

Don't guess, be systematic. I was chasing an oscillation on an amp for a year, and it turned out to be a power supply in a different room of my house.
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'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright

Modern Ground Schemes
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B+ Voltage Reduction
Amplifier Tools & Parts Info


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