Rolling Volume Issue

[Dilemma]

I've got a very new Roadster Combo that's already fallen victim to the rolling volume issue. I read the FAQ and it looks like I should replace V3 and V4. It looks like the preamp tubes are Mesa branded JJ Electronics. Russian?

The question is, will installing only two preamp tubes have any effect on anything? These don't need to be matched do they?

Thanks everyone,
Thomas

 

[Dilemma]

I just returned from Guitar Center where I purchased two Groove Tubes, made in China. So far, the problem appears to have been solved.

 

[KiwiJoe]

Glad the problem is solved, and in answer to your question, no, preamp tubes don't need to be matched.

And, just curious - Why, in both posts, did you feel the need to mention where the tubes were made?

 

[Dilemma]

Glad the problem is solved, and in answer to your question, no, preamp tubes don't need to be matched.

And, just curious - Why, in both posts, did you feel the need to mention where the tubes were made?

Read the FAQ regarding this rolling volume issue. It specifically talks about Russian vs China tubes. That's why.

 

[Dilemma]

Spoke too soon. Problem still present. ****

 

[mesaboogie6L6]

Do you mean your volume is fading up and down? If so that would be a power tube issue.

 

[Dilemma]

Do you mean your volume is fading up and down? If so that would be a power tube issue.

Yes. It modulates from very faint to normal. All channels.

Q: My amp gets quiet and then loud (rolling volume). What could be the cause?

A: Check to see if your Cathode Follower preamp positions (typically V3 & V4 on most Rectifiers) have Russian tubes. If they do, try installing some Chinese preamp tubes. 90% of the time, this will solve your volume roll issue.

I read this in the FAQ section and went after V3 & V4. Didn't work.

 

[mesaboogie6L6]

That is a typical symptom of worn power tubes, same thing happened to my mark III coliseum, changed power tubes and fixed it.

 

[domct203]

I've got a very new Roadster Combo that's already fallen victim to the rolling volume issue. I read the FAQ and it looks like I should replace V3 and V4. It looks like the preamp tubes are Mesa branded JJ Electronics. Russian?

The question is, will installing only two preamp tubes have any effect on anything? These don't need to be matched do they?

Thanks everyone,
Thomas

V3 & V5 are the cathode follower positions in the Roadster.

The current Mesa 12AX7 is indeed a JJ, and are fine in those positions.

http://forum.grailtone.com/viewtopic.php?f=4&t=25102&start=19

Dom

 

[Dilemma]

domct203, first of all, thanks for taking the time to respond. Much appreciated.

I'm a little confused however. You say "The current Mesa 12AX7 is indeed a JJ, and are fine in those positions" yet I'm still having this issue. The two tubes I recently purchased are Chinese made Groove Tubes. Would changing out V3 & V5, rather that the V3 & V4 with the Groove Tubes be the solution?

I believe this is what you're saying based on the link you provided.

Thanks again,

Thomas

 

[domct203]

I don't know if that would be the solution, but I would at the least give it a try.

I was simply correcting your mis-information. V3 & V5 are cathode follower positions in the Roadster, and New Sensor brand tubes should be avoided in those positions.

Have you eliminated any other source of poor signal (bad cables, dirty jacks etc)? Does the issue happen with just the guitar straight into the amp with the FX loop Hard Bypassed? I had the same issue with a used Stiletto I bought, turned out to be dirty contacts in the FX Loop jacks.

Good luck, I hope it is something as simple as a preamp tube or cleaning contacts.

Dom