Loud Noisy Humming reverb

[Dalaware]

Hi

This is my first post here and I hope some one can help me. I have a Boogie Mrk IV combo 2003 I have the following problem, when I switch on the boogie I get a Loud Humming
Sound from the speaker if I turn down the reverb the Humming stops, when I say Humming this is a very loud Humming. I have had the valves changed recently but only the small ones
The four large valves were not changed, if I play with the reverb turned off every thing is normal
No jumps in the volume. Lead rhythm and clean all as expected no cracker ling no fuse blowing just Boogie heaven. Thanks in advance.

 

[lento]

Hi,

I had exactly the same problem as you describe. If you read the post here

http://forum.grailtone.com/viewtopic.php?t=13856&highlight=

you'll find I solved it by disconnecting the fan ! Obviously not an ideal solution (after all, it's Mesa's cable routing) but as I didn't like the fan noise anyway, it worked for me.

Hope this is some help.

regards
Lyn

 

[6L6C]

Make sure the two cables from the reverb tank to the chassis have a good connection, after servicing my amp I had left the cables off and with that reverb on it was noisy as hell.

Another thing maybe one of your new preamp tunes is whacked replace V4 with one of your old ones to confirm this and maybe V3 also.