Weird siren noise from my amp

[johj]

Recevied the USB isolator today and it appears to eliminate the problem completely!
 
I guess that confirms the problem was ground-loop related..?

 

[ClieOS]

Yeah, that sort of confirm it is ground loop. Anyway, good to know it is fixed.

 

[johj]

Quote:

Yeah, that sort of confirm it is ground loop. Anyway, good to know it is fixed.

 
Yup! Thank you for your help

 

[mich41]

Be careful though, because you will probably get the same noisy surprise if you accidentally touch this amp's case with any other grounded object.