Hmmm... something funky happened with my JVM tonight

Drew_TNBD

Got into practice.. clean channel was fine, OD1 and O2 were fine... crunch channel wouldn't make any sound whatsoever. Couldn't figure it out, so I just left it and used my OCD.

Get home... swap tubes around. Sweet fuck all difference.

Turned all the EQ knobs a bit, and noticed a bit of crackling with the treble knob. Turned treble knob around a bit more, and the channel came back to life... and it now seems fine.

WTF?

Van_Hayden

Not at all familiar with the JVM but if it's a standard tone stack you've probably found your fault. The whole signal flows through the treble pot, funky pot there and it will go silent. Could just have been a bit of crap in the pot. I'd keep a suspicious watch on it and if it does it again swap it.

digitalscream

Dude, your experience really isn't selling me on Marshall build quality...you've got their flagship amp, and still you've have to have the mainboard replaced and now you've got a dodgy pot.

I'll stick to my £200 Jet Cities

octatonic

JVM's have had a lot of build quality issues- check the Marshall forums- there are loads of threads.

ICBM

Unfortunately the pots on all the modern Marshalls are crap. (Anything except the reissues basically.) They're not alone though, a lot of companies are using them now.

Drew_TNBD

Could've been just a bit of cruft. I know, it isn't that great. The amp does sound amazing though! I was bitching last night about how I was done with tubes and was going all digital, lol. But there is a part of me that is seriously tired of the maintenance of a valve amp.

Handsome_Chris

How long have you had it, and do you use potentiometer cleaner? 

Drew_TNBD

I've had the amp since last October. I had the main board replaced about a month or so ago. I've not used any pot cleaner on the amp at all. It *seems* fine now, so I'm going to assume it was just some cruft got into the shaft or something.

But yeah... sometimes I wish I'd just gone feckin' all digital!!

Handsome_Chris

I've heard about about JVM issues, but I think your amp is cursed.

Digital is ok, but I feel like a bit of a fraud as I do not use all the "amps" available.  In fact I try to use as little as possible after what I took away @Clarky and @Octotonic advise at Axe-Fest UK last year - To paraphrase, don't use lots of different amps blocks as it messes with the sound guy.

Drew_TNBD

Yeah I agree. I'd only really use a good clean model and a good gain model, and I'd get the crunch with different levels of input gain and output volume.

But it's besides the point, not switching until I have to at this point!