Pulled out two tubes, Tverb tremolo disappeared

[naciketas]

Hello everybody, this is my first topic on this board.
After reading some threads on pulling out tubes to halve the power, I resolved to follow the instructions and everything seems to work fine except for the tremolo which has disappeared. Once placed the tubes back, the tremolo came back again. Any idea, is it normal or a bad sign ? I can live without the trem for a while (thinking about Yellow Jackets), until the purchase can I go on with two tubes only?
Thanks in advance
Giovanni

 

[mesanomad100]

dont mean to make ya sound silly but did ya pull the power tubes or preamp tubes,I havnt heard of this before and Im not a tech,I was always under the impression things like reverb,loops etc ran off preamp tubes,you havnt pulled a preamp tube ????????????

 

[MesaENGR412]

yeah, that's what I was wondering too....It wouldn't be a good idea to pull preamp tubes and run the amp.

-AJH

 

[mesanomad100]

I've never heard of that happening,as all major functions are normally asigned to a preamp tube,surely the power tubes are there for POWER,volume not for particular functions on the amp???????????

 

[Elpelotero]

Naciketas,

You need to pull a pair of the outer or inner power tubes. These are the big ones on the back. You also need to pull one rectifier tube (the big ones on the back right).

Do not under any circumstances pull the small preamp tubes. This is most likely what you did. You pulled the preamp tube for tremolo.

 

[jbird]

(Here we go again :roll: ) So let's see, you wanna pull two Power tubes in order to get the tone of a cranked amp at bedroom levels? The degradation of tone usually is'nt worth it, use the master volume! :idea:

And the yellowjackets are for? :?:















Note: I know what yellowjackets provide for, I'm asking beacause it really has nothing to do with the aforementioned? :arrow:

 

[Boogiebabies]

The tremolo is a 555 timer circuit that is fed via relay to the effects loop and added to the phase inverter. Sounds like you pulled the preamp tube for the effects loop.

 

[naciketas]

Thanks for your replies.
As I said, I followed the instructions and pulled out the power tubes, I didn't even touch any preamp tube.
I'll try to swap the pair: outer instead of inner, just to give a chance, but from what I understand [being Italian (Firenze)] the trem has nothing to do with the final stage, I'm not so optimistic and believe there's something wrong with the heads ( the Tverb's and mine of course :wink: )
Again any reply will be much appreciated, I can't pass to a LSC/LSS at the moment so it would be nice to use my Tverb halved and yellow jacketed, 20 w instead of 100w at home is a good trade off!
Thanks again.

 

[Elpelotero]

maybe you just had bad luck and your efx loop tube blew out when you pulled the power tubes. it may have been a coincidence.

 

[naciketas]

Just swapped, same story.
Well, as soon as it is on the trem works.
So I played just a few minutes then put on the stand by, went out to smoke a cigarette, but once got back the trem disappeared :shock: !
I don't know what to think, maybe I should give up with this idea .

 

[jbird]

How 'bout returning the amp to "normal" conditions to diagnose the problem? :idea:

 

[naciketas]

So this last reply seems like a final word to the thread, now I'm gonna print the schematics and wait for the right time to carry "carcassonne" to the doctor, who, after a telephone call, told me that he has no idea: not encouraging at all (he didn't even heard about pullig out tubes, power tubes).
Anyway this thread is always open for every suggestion, thanks again.

 

[mbmesa]

You probably have a poorly seated or intermittent preamp tube and knocked it while pulling out the power tubes. I had a similar situation with V1 it would cut in and out at various times. A preamp tube swap fixed the issue.