Loud popping sound from speakers

Isolate what component is causing this.

Unplug all components from the amp but the speakers and turn the amp on.

Any issues? yes? then it is the amp. No? then plug the pre-amp in with nothing plugged into the pre-amp and turn it on. Issues? Yes, then it is the pre-amp. No? Then plug other components into the pre-amp one at a time until you determine the culprit.

If the problem is the amp, it could be several things. The amp would need evaluation and repair.

Probably not a blown fuse. Blown fuses generally stop one or both channels from working at all.

Bad capacitors possibly