Pedal Pop. Amp Pop??? Cheggers plays pop...

Started by Greenballs, November 19, 2021, 03:49:36 PM

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Greenballs

So, when I measure for leaky voltage on the output jack of the pedal with the pedal plugged into amp I get a reading of 0.43 on the meter. When I measure the same output jack with the pedal not plugged into the amp (pedal still switched on) I get a reading of 0 on the meter.

Would I be correct in thinking that the pedal would be pop free when plugged into a different amp, due to my amp being the source of the leaky voltage?

GibsonGM

It's not an unreasonable assumption to make...why not just try it out?
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fowl

Is it a tube amp?  Is the first preamp tube a JJ brand?

Greenballs

Quote from: GibsonGM on November 19, 2021, 04:22:55 PM
It's not an unreasonable assumption to make...why not just try it out?

Can you ship me another amp??? ;D

Greenballs

Quote from: fowl on November 19, 2021, 04:28:30 PM
Is it a tube amp?  Is the first preamp tube a JJ brand?

It is a tube amp, the first preamp tube is a Tung Sol.

idy

The question as posed is maybe awkward...if the amp is leaking DC, you don't need to have a pedal to measure it, just a cable...cable plugged into amp, is there voltage on the other end?

Then separately, pedal powered up and cables plugged into both jacks...is there any voltage on those cables?

You need to separate the two possible culprits, like a cop putting the two suspects in different rooms and sitting down for a chat...

GibsonGM

Quote from: Greenballs on November 19, 2021, 04:44:19 PM
Quote from: GibsonGM on November 19, 2021, 04:22:55 PM
It's not an unreasonable assumption to make...why not just try it out?

Can you ship me another amp??? ;D

Sure, where you at? :)   Just wondered if there was another one available.    What  IDY said, just test the amp and see what's up.

What is the amp make/model?
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Greenballs

Quote from: idy on November 19, 2021, 05:26:52 PM
The question as posed is maybe awkward...if the amp is leaking DC, you don't need to have a pedal to measure it, just a cable...cable plugged into amp, is there voltage on the other end?

Then separately, pedal powered up and cables plugged into both jacks...is there any voltage on those cables?

You need to separate the two possible culprits, like a cop putting the two suspects in different rooms and sitting down for a chat...

Well, I sat them down, shone a bright light in their faces, interrogated them and I think its the amp. I'm getting a reading of 0 on both input and output jacks of the pedal. A straight jack plug into the amp reads 0.58. I'm reading it it's rights as I type...

Greenballs

Quote from: GibsonGM on November 19, 2021, 05:28:57 PM
Quote from: Greenballs on November 19, 2021, 04:44:19 PM
Quote from: GibsonGM on November 19, 2021, 04:22:55 PM
It's not an unreasonable assumption to make...why not just try it out?

Can you ship me another amp??? ;D

Sure, where you at? :)   Just wondered if there was another one available.    What  IDY said, just test the amp and see what's up.

What is the amp make/model?

It's a Carr, The Bloke.

If you could send me a Dumble and a Trainwreck, just to be doubly sure, that would be great!

fowl

Not knowing your amp's topology, and assuming the first stage is not grid leak biased (unlikely), you have grid leakage from V1, the first preamp tube.  I've dealt with it before.  Just replace the tube with a good one.

PRR

A DC-coupled 12AX7 grid with 1Meg gridleak resistor will float to a part-volt. It's not a MOSFET. The grid is naked wire. Electrons will randomly run into it, even if charges discourage it.

If a 100K resistor across the input makes the half Volt goes toward tenth Volt, there's nothing wrong. That's what tubes do.

Yes, a part or even tenth Volt of DC on a 0.020V sensitivity input is a big pop.
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idy

So now you find that this small voltage is not necessarily a sick amp, but may cause pop. IS there pop when you bypass pedal? (the title says it, but the post didn't.)

If so you have options. One is a buffer between pedals you bypass and the amp.
Many pedals have buffers, reverbs and delays are common last in line, one with a buffer fixes this....