My Mark V is irritating me... Snap, crackle, pop...

[lhrocker]

When I first got my Mark V (bought used), there was all of this crackling, which the seller said it was because of the fan and if I had any issues, I could get it fixed under warranty. Well, I got the amp home, pulled out the power tubes and found the 2 middle tubes looked like someone spilled cola on them. The tubes were filthy and covered. I replaced the tubes and the amp now works flawlessly. Sometimes you never know what to expect.

[Grandturk]

Does it only start making noise after its been played a while? i.e. if its been running for 1/2 hour first and then it starts making noises? Because to me that sounds like its heat related.

[MakeAJazzNoiseHere]

I have nothing in the loop and no pedals... Just a guitar into the amp.

I've had it crackle immediately, or after being on for an hour, or NOT crackle after being on for several hours... That seems to rule out heat.

It's not any guitar wiring issue, it isn't any particular guitar that causes the issue to start and once the problem occurs, it doesn't matter what guitar or instrument cable I use.

I did remove & re-seat all the tubes and it's working fine now like I said. Of course it worked all day yesterday from like 1 PM to 7 PM and then started buzzing like a sonofabitch at 10:30.

Thanks for the suggestions so far guys. My house wiring is old, but these outlets I'm using are new (Romex, grounded) outlets straight out of the box, none of my UPS or surge protectors indicate a ground fault, but I'm not sure that completely rules out the wiring... Just seems strange it will work for hours and then go completely bonkers. :think:

[Grandturk]

How about static electricity? Are you on carpet? Wearing wool socks? That kind of thing? I get bad crackle on my guitars with a pickguard in the winter.

[RacerX]

You're making too many jazz noises there?

[toejam]

There are gremlins living in your amp...

[Grim]

There are gremlins living in your amp...

:O

[Grim]

You're making too many jazz noises there?

That was amazing. Kudos to you!

[MakeAJazzNoiseHere]

I'm currently waiting for the Mexicans to get home and start talking to their ese's.

Meaning... It's been on all day and not a crackle out of it (except when the A/C kicks on, for about .5 seconds) and it of course sounds excellent.

[Grandturk]

and it of course sounds excellent.

Oh, I thought you were playing it - my mistake!




ZING!!!

[emperor_black]

Contact cleaner. All tubes prongs and sockets. Instrument jack, knobs, etc. That should make it go away.

[MakeAJazzNoiseHere]

And, it's back. After working perfectly all day, getting good and hot, trying several guitars, etc. this evening I have it already plugged into a guitar, turn it on, wait 30 seconds, kick it off standby, and bzzzzzzt....

I'm almost certain now, there is some jackass with a ham radio set or something like it in my neighborhood.

So, when the guitar volume is turned down, the crackling happens.

Turn the volume up 1/8 turn and no more crackle.

Same thing, if you plug in a cord and short the tip and sleeve with a little piece of metal, you get a nice antenna (loop of wire) and you get lots of crackling.

So, I'm pretty convinced there is nothing wrong with the amp, and it will work fine tomorrow morning again, when Mr. Jackass Ham Radio Operator is at work.

[Grim]

Why don't you take it (I know the Mark V combos are heavy but still) to a friend's house and see if you get the same effect there?

[Hellbat]

Does the Mrs. own anything with an electric motor that she might be turning on when you start playing your guitar?

[toejam]

So, I'm pretty convinced there is nothing wrong with the amp, and it will work fine tomorrow morning again, when Mr. Jackass Ham Radio Operator is at work.

Do you think Mr. Jackass Ham Radio Operator has the same problem and curses at his radio every time you play heavy metal guitar? :ROTF: