Mesa Rectoverb 50 cutting out

[torquelive]

My rectoverb 50 has been cutting out intermittently for no apparent reason. I am running JJ 12ax7's, and JJ 6l6's in the amp. Playing along just fine for over an hour the other day when it started cutting out. No sound for a second or 2 then back to normal several times over. Went back the next day everything was fine could not duplicate it. Went to practice last night played for an hour or so and it started doing it again. Took it home. Turned it on for 2 hours, just left it run, could not duplicate the problem....Totally baffled...Also when it does the cutting out stuff, when i put the amp on standby i get a loud pop. Any other time i put it on standby its quiet.
Any ideas????

 

[Restless Rocks]

I've seen bad solder joints in the high volatage supply cause that. Bad stdby switch?

 

[domct203]

Something else to consider is the "cathode follower" positions in the preamp.

The following quote is from this thread.

Hope it helps!

Dom

Here's the info from the Mesa Memo...


SOUND “DROP-OUTS” / INTERMITTENT SIGNAL

One Possible Cause



Most (but not all) Mesa/Boogie amplifiers have one or two “cathode follower” tube
stages in their preamps. Tube selection is CRITICAL in these stages.



Specifically, in a 12AX7 tube used as a “cathode follower”, the voltage difference
between that present at the cathode, as compared with the heater voltage, can be
withstood or tolerated by certain types of tubes, whereas other tubes will fail. The
failure of a “cathode follower“ tube will cause sound dropouts or signal loss.



For the past few years, Mesa has been using two types of 12AX7 tubes: ones
originating in Russia (Sovtek EH), and ones originating in China. The Russian (Sovtek)
tube is NOT reliable as a cathode follower. Of the tubes we are using today (March
2008), ONLY THE CHINESE 12AX7 IS RELIABLE AS A CATHODE FOLLOWER.



In conclusion, if you are troubleshooting for signal dropout in a Mesa/Boogie amp,
suspect a cathode follower tube, and try replacing it with a Mesa 12AX7 that is marked
as “CHINESE” (silk-screened on the tube itself).



Below is a partial list of Mesa amps and cathode follower tube locations:

GUITAR AMPS BASS AMPS

Lone Star & LS Special: V3
M-Pulse: V2
Stiletto: V3 & V4
Venture: V2
Road King I: V3 & V4
Big Block 750: V4
Road King II: V3 & V5
Titan: V4
Roadster: V3 & V5
M2000: V2
Dual & Triple (2ch or 3ch): V3 & V4
Bass 400+: V2
Tremoverb: V3 & V4

ANOTHER POSSIBLE SCENARIO may occur in the “SPONGY” (or on some models,
“TWEED”) power setting: the reduced filament voltage may cause very low output from
a RUSSIAN preamp tube. Again, the recommended fix is to replace the “sagging” tube
with the CHINESE type of Mesa 12AX7 - which are more immune to this type of failure.

 

[jsabo]

... just sold the rectoverb
to me, this amp is garbage.

after the honeymoon, came to realize that the amp does nothing but Numetal well.

i took it in for repairs because i was having fizzy reverb issues and EVENTUALLY the reverb started cutting out entirely.

i took it in and they didn't know how to fix it, even after 3 mo (a certified mesa tech), so i traded it in.

not surprised if i hear even more issues upcoming.

 

[torquelive]

Swapped tubes in preamp section, V3 and V4 to chinese tubes. Replaced scratchy master volume pot, removed reverb tank. Disconnected it altogether never use it anyway. Resoldered the effects loop mod just to be sure. Haven't had the problem recur yet. I have 7 upcoming gigs and I'm nervous as hell about what this amp might do. Too poor to trade it in right now so i have to get to the bottom of it. I did notice one thing i hadn't before, when the amp started acting up the air conditioner in the practice room made the lights flicker. Thinking, hoping it is a power thing. We'll soon see. Thanks for your responses. I'll post the results soon.