Trouble Shooting Help, Please

[theRockGuitarGuy]

Hey Guys: Any help, suggestions, comments, wisdom is appreciated...

My Mark V is behaving badly. The output is greatly weakened - sounds like a blanket is over the amp (in all 3 channels) and then I began cutting in and out sparatically... signal goes away and then comes back - over and over again...sounds like a preamp tube, right?

So I take everything out of the loop and plug straight into the amp. Result is the same...weak.

Switched the Hard bypass and BINGO - the amp came back to life. Brilliant. Sounds like a Boogie again.

So, is this the V6 preamp tube? the Phase Inverter? or Both?

Or am I totally off base?

Thanks in advance for any help.

 

[SteveO]

It could be one of the units that is in the loop (or a weak battery in one of them), or one of the patch cables you are using. It doesn't sound like the amp is the culprit if it works fine when all the extra stuff is removed from the signal path.

 

[APEMAN]

-

 

[theRockGuitarGuy]

Thanks guys.

Okay...I removed everything. Now, it's just me, the guitar and the MV. Same problem. Performance is significantly hampered when the loop is active. Turn the loop off (via the toggle on the back) and I'm back in business and the amp sounds great. Nothing is in the loop, but it sounds terrible when the loop is engaged.

I changed the V6 - same thing. Tried 2 different (new) preamp boogie tubes. Just for kicks, I went thru each preamp tube (all 7) one at a time. Same result each time. Any other suggestions?

Again, thanks for the feedback.

 

[APEMAN]

-