Crackling sounds from a JCM 900 MKIII

[alnikman]

About a week ago, I traded my Blue Voodoo head for a JCM 900 MKIII 2100. I have noticed that when I set the pre-amp volume and the gain levels high, I get a faint crackling sound coming out of the speakers. However, when I engage my modded TS9 pedal, the crackling is louder and more noticeable. I checked to see if it was the pedal giving me the issues by playing through my practice amp, but I did not get that noise when I tried it. So, I am assuming that I have a problem with my head.

I am hoping that this is an easy/cheap fix. I was thinking of turning around and selling this amp after the trade, but I took quite a shine to it when I was pleasantly surprised as to how awesome this thing sounds.

 

[mwalluk]

Re: Crackling sounds from a JCM 900 MKIII

Don't sell it, you'll regret it. Even if it costs you a few extra bucks to repair it, it'll be worth it in the long run. Now for diagnoses....

Is this a head or combo?

Could it be the speaker?

More than likely it could be just a BAD POT. Those things tend to go and are an easy, cheap fix. Try taking some compressed air and cleaning out the head. Shoot the air in any open holes (inputs, outputs) see if that helps any.

Like I said, I wouldn't sell it unless something major is flawed.

 

[glassman]

Re: Crackling sounds from a JCM 900 MKIII

My experience with these amps leads me to suspect a cracked solder joint on the input jack. It requires removal of the main board so I would suggest that you take it to a tech to have this work performed. COnsider having the amp re-capped while it's in there as a precautionary measure...it's about due anyway.

 

[alnikman]

Re: Crackling sounds from a JCM 900 MKIII

This is the 100W head. I doubt that it is coming from the cab, since I bought a good as new 1960AV a few days ago.

I was thinking about taking it to an amp tech anyways, but I was curious to see if anyone else here has had the same problem with these amps.