Stetsom EX 8k crackle in speakers

[barber02]

There is noise on pin 5 of U3 with no audio being fed into the amp.

Probe is 10x. Scope is set to 100mv 2us.

 

[Perry Babin]

With the same scope settings, what do you see on pin 4 of the IC?

 

[barber02]

This is pin 4.

 

[Perry Babin]

This is just noise. That's why I recommended grounding the scope closer to the op-amp.

 

[barber02]

I did ground it close to the op amp. I grounded to the casing of the over clip switch next to the speaker terminals after you mentioned grounding close to the op amp.

 

[Perry Babin]

Well, it's noise. I don't know why you're picking it up with a close ground.

That's not what you're hearing. It's well above what you can hear.

I think you're going to need a signal tracer with a floating ground to find the noise. Item #18 on TT10 if you have the tutorial.