Mark V Buzzing (Resolved? and Track Added)

[Brianiac5150]

Well...as fate would have it...mine anyway...I planned on getting some recording done this weekend and bam! Mark V takes a shyte on me. Turned it on this evening and it's sounding as though it's not completely coming out of standby. When playing clean on Ch 1 I do not get a full tone, instead it sounds like what tube amps typically sound like when you switch the standby on and immediately start playing. Kinda farty, distorted.

One of the tubes (second from the right when looking at the back of the head) doesn't appear to be as bright as the rest. I'm no amp guru, so I haven't the slightest if this is the issue.

Went to call Boogie support and, of course, they're not open on Fridays.

F!!!

Any input or ideas on this from anyone here would be greatly appreciated. I did not, but am going to search through the forum a bit later and see if anyone else has experienced this issue.

EDIT 1: Just turned it off, at supper, came back (unplugging RJM MAG), powered it up and it sounded fine for a few minutes and then the buzz came back. Ch 3 has considerably less gain, Ch 2 doesn't sound as good as usual, but not near as bad as 1 & 3. Buzz is still audible on Ch 2, but almost sounds like intended distortion. Went through the wattage ranges and still present.

EDIT 2: After leaving it sit again for a while, I turned it back on, plugged in and played without the breaking up, buzzing sound, however, Ch 3 has completely lost its punch. It was always (I run Extreme mode most) louder than the other two. I cranked it to 1-2 o'clock and it was just kinda loud. I wouldn't dare do that before. 11 o'clock was punishing.

 

[screamingdaisy]

What you're describing sounds like a failed preamp tube. Sometimes it's intermittent and heat/vibration will trigger it. While the amp is on try tapping each tube with a pen/pencil and if you hear mechanical noise amplified through the speakers that tube is done.

 

[Brianiac5150]

Thanks for the info, I'll give that a try in a second.

I did plug in this morning, went through several guitars (passive & active) to see if that was the issue, however, now everything seems to be back to normal, which leads me to believe you're very much on to the issue.

 

[Brianiac5150]

Well...I'm no amp guru, so digging into the back of the Mark V head is somewhat daunting for me. I was able to stick a pin in there and do some tapping, but didn't hear anything. I certainly don't want to spend the time dismantling everything, as the Wife and kid left me alone today for only a few hours and I wanna play this monster. I will mess with it more throughout the next several days and see if it recurs. I certainly hope not, but - then again - I'd prefer to find out if there's an issue and fix it instead of wait for it to happen again.

Although this is an extremely loose mix, I threw down a few tracks this morning with it to the following result:
LINK REMOVED

I frickin' love this amp!!!

 

[hendrik84]

great sounds!