MK IV Acting Weird Trouble Shooting Question

[Ranger Jim]

My MK IV is acting weird !!!! I turn the amp on stand by to let it warm up before playing 4 to 5 min. When I turn it on the amp acts like it is not warmed up, the volume slowly comes up, it is distorted and sounds like it just ate at McDonalds. The sound will eventually clean up and act normal. Have any of you out there experienced this, could this be a bad tube :?: Thanks :lol:

 

[ToneAddictJon]

Are you turning the standby switch on and then the power switch??

 

[MrMarkIII]

Are you turning the standby switch on and then the power switch??

Ha! No one could possibly be that clueless, could they?
RTFM, RTFM, RTFM, RTFM...
(This is why chicks get pissed because, being REAL MEN, we don't ask for directions.)

 

[Herbie the Rad Dorklift]

Lol, I used to turn standby on first when I got my Fallen Angel years ago.

 

[Ranger Jim]

:lol: No I am not turning the std by switch on and then the power,,,,,,,, I bought this amp in 1994 new and have been using it sinse. I have been playing guitar for 35 years, I don't think I would make that mistake,,, haaaaaaaa :lol:

 

[ToneAddictJon]

Good, I just thought I'd ask the obvious question first
It could be a bad tube, but I've never experienced that exact problem before.

 

[Axis39]

I had a somewhat similar experience, though not quite as extreme.

My amp volume was funky between channels... RHY 1 was really quiet compared tot the others. I used another amp for a while and when I turned my MK IV back on and played it last month, it was 'flubby' sounding at any volume. I read this forum and decided that it must be a preamp tube.

There was the original spare inside the cabinet and I slipped it in V1.

Problems solved. Now it sounds great and I've fallen in love all over again!

 

[Ranger Jim]

Thanks for the input. I will try a pre-amp tube and see what happens. I want to re-tube the amp, I just need to figure out what tubes to get. I got SV6L6 and Mesa pre-amp tubesin it now. I would like to try some different ones but there are so many on the market and alot of jabber about all of them. What do you think about JJ's or Ruby??????? Thought about 6V6 tubes in the power section but from what I am reading it sounds like don't use them.

 

[Tyrant]

I had a similar problem but not exactly at startup. All it took was cleaning all the jacks with deoxit. Trouble free since. GL