Xr8600 owner . was in truck in the cold, and brought it in for a gig and started crackling, and after about 20 minutes. lost of treble. gone. is this fixable? reset? i saw some of your posts about "co

buy a canister cold spray and spray on some active components if the noise begins You have a thermical failure in a component on the board can be faltering resistorcircuits or resoldering some active components.

Get a meter and check the resistance on the speaker. Looks like a speaker may be blown but with the description of the crackle noise from the slide controls you might have a bad pot in the unit or the pot has come loose from the board. This could explain why the speaker blew out

I suspet you have it connected in such a way that the ohmage the power amp section is seeing is toolow cauysing it to overheat and then fail.

Try some standards -- unplug EVERYTHING, and use the headphone out jack first. After 2-3 minutes, and it's still crackle or buzz, then it may be something wrong with the internals. Could be simple, but may be more than what the unit's worth to fix. If it DOES NOT crackle/buzz, then you might have a bad connection/cable somewhere. Just plug them all back in, one-at-a-time, and wait in between plugging in. Best of luck!

Please, take it to a tech in your area, or look for a good one to ship it to. An 2007 amp is not old at all.

I had the same issue with my AS100D. When I first bought it the treble knob on the top channel was very responsive. At 10 is was unbearably "trebley". I was getting plenty of "high" treble set at 2:00, even 1:00. Then after about 6-7 mo, I started to feel it the brightness was leaving the amp. I was now putting my treble knob all the way to 10 and keeping it there, and it still wasn't enough. I had it serviced twice, no solution. Marshall got into the act and after months of going back and forth, they finally replaced the whole amp with a new one. I just got it. The treble was incredibly bright at 10, just like the former unit. But now after just a couple of days, I can already see the treble knob is not as responsive. I can't believe it! Now what?

I don't believe there is a mute function on the XR684F unit. There is a mute on the XR8600 but they probably use different boards in it. The mute button for the XR8300 and XR8600 are near the effects selector button and LIKELY is board mounted and would not have a J111 connector. If the electrical function is in the XR684, it MAY just be pads like test points, to only be used during testing and troubleshooting.

resolder the three legs of the pots back down to the pcb. usually the treble feeds the bass, then from bass to mid then to ground. so if treble and mid are working its hard to imagine why the bass wouldnt be working. i would try to resolder, as you might have cold solder joints. keep it unplugged, pull off the knobs, open it up, remove the pcb screws and pull/flip out the pcb and resolder all of the pots.

In YOUR amp, take a pencil and tap teh sides of the tubes GENTLY, listening for any crackling... note SOME microphonics is normal in the preamp stages.

Since retubing it fixed it once, it is likely either a tube was bad OR a pin of a tube wasn't quite making so replacing the tubes cleaned it and made it work. Tubes DO go bad, especially when they are vibrated like in these amps... BUT don't just replace the lot, try to find which is at fault..

On your friends unit, LIKELY an electrolytic bypass capacitor for one of the reverb preamp stages has dried out and needs replacing.

if this a tube amp then your tubes might be going bad. but if it is a solid state amp then im not to sure whats going on.