After about 3 months of very light usage (home use, ~20 hours), my Code 50 developed a harsh noise problem: https://youtu.be/S2cTK8fsfTE. It's on every preset and can be heard via the speaker and when using headphones. I tried using different guitars/cables/power cords/rooms/outlets, reloading firmware, and resetting the presets to factory default; but the noise continues. Anything else I can try before I return it for replacement/warranty work?
I have an old acoustic AS80R that I have been using with a semi acoustic electric guitar for a nice clean sound. I like the sound of the combo (it has Celestion speaker elements), but the amplifier makes a constant 100 Hz buzz as soon as I turn it on, even when no guitar is connected. The buzz is louder than what I consider normal. Two professional service shops have tried to repair it.
Could I use it as speaker cabinet and replace the amp with a separate amplifier & how to do it?