Marshall Avt 50w Clean Channel TROUBLE!

[Piernamala]

Hey guys, i've just got an used avt50 and yesterday while playing through the clean channel it started to make distortion like when im on the overdrive channel, also when that happens, the green led from the clean channel turns off. This happened several times and it stays like that for about 2 seconds and then it comes back to normal. It only happens when the footswitch is plugged but the footswitch is brand new. What's happening??

[Twist]

Since you have a new foot switch, the problem may be in your foot switch jack. Unplug the foot switch and while strumming a chord tap on the foot switch jack on the amp and see if the amp switches by itself. It may be subject to a cracked or cold solder joint. Also repeat this with the amp switched to the other channel.

[Tbonezz]

I have the same trouble with my avt50. The footswitch is the original one though. I recently changed the tube to see if that may be the problem because my all tube Peavey classic 30 did the same thing when a power tube blew. No luck. It still happens. I'm not too concerned because I only use the avt to practice, but it is startling when I'm trying to play at a low volume so I don't wake the family and suddenly the volume swells and distorts. Anyone

[nullsys]

I think I have a similar problem with a solid-state CRATE practice amp, dual channel.
After a while of being on ( random times ) the channel SWITCHES over to the gain channel and has trouble staying back on clean. I also have a marshall which is producing an overdrive sound on the clean channel. Im looking into these also

[52 Bill]

I'd agree with Twist.

The footswitch jacks will often either get pulled loose from the board. Or just like FX loop jacks, the normally closed circuit switch will be come dirty or oxidized and will make and break contact as the amp is vibrated. Try cleaning the jack with a little spray of contact cleaner, followed by a few quick in and outs with a plug.

[Enzo]

With that symptom on any Crate amp, THE first thing I check is the cutout contacts on the FootSwitch jack - they are not closing properly or they are dirty. it is also possible on your other brands.

[Tbonezz]

I use a digitech rp100 through the amp on the clean channel usually and I don't use the footswitch for the amp too often. So, I decided to remove the footswitch just to see what would happen. I haven't had the problem since. Thanks for your help everyone. I'm going to clean up the jack and the plug and see what happens.