Popping Sound On Amp When Playing Guitar

[GuitarGuy2007]

I have a Fender Ultimate Chorus guitar amp that is making popping sounds when I play guitar on the distortion setting. It seems to have gotten worse. It is really prevalent when I use a pedal with the amp. Is this fixable? Is this a voltage problem? I would appreciate any suggestions. This is not a tube amp. What can I do to solve this problem?

[Enzo]

So look for DC offset at the output pins (pins 2 and 7) of U2 and U3. If the clean channel sounds OK, and only the dirt channel is affected.

[GuitarGuy2007]

Thanks ENZO.

How do I check for DC offset? I am not sure where pins 2 and 7 of U2 and U3 are located.
Charles.

[Enzo]

I don't mean this unkindly, Guitarguy, but if you don't follow that suggestion, maybe this repair is more than you can do. The problem will not be something simple like changing a tube would have been. This will require finding the bad part, and replacing it on the circuit board.

All ICs count their legs the same way. Look at the IC with the notch at the top center or with the round dot upper left. Pin 1 is now upper left, and the pins count down the left side,and then up the right side. SO pin 4 is lower left, 5 is lower right and 8 is upper right - on an 8 leg IC.

DC offset means there is a DC voltage where there should be none. Pins 2 and 7 ought to have close to zero volts DC. If you find 15v there or several volts, then there is a problem.

We measure these voltages with respect to the chassis.

DC offset is just the first thing to my mind, it could also be something else.

[GuitarGuy2007]

I appreciate any advice I can get.

I can follow the instruction. I am novice, but inquisitive.
Charles.

[Enzo]

Well then, I explained how to find the pin numbers on the ICs, so get out your volt meter, connect the black probe to chassis and take some readings.