Roadster Volume Loss

[guitarbloke]

Out of the blue at my last gig , I experienced a big volume drop - something like a 40-50% drop.

It's never happened before. I'm using winged =c= power tubes which I tried swapping back to the stock Mesa tubes - didn't make any difference (other than worse tone from the mesa tubes).

So if it's not the power tubes, what else could be causing this? I'm running a US import Roadster head through a step down transformer (I'm in the UK) but it's been fine for the whole time I've had it - about 3 years or so.

Any ideas/suggestions would be gratefully received

 

[knotts]

This happened to me the other day right before a gig. It turned out to be that one of the power cables to my pedal came unseated; although it looked like it was in. Since the pedal was true bypass (supposedly) it passed the signal but it was hardly audible. Have you tried going direct from your guitar to the amp through a known working cable? If you have don't have full volume, it is amp related.

 

[guitarbloke]

Hi Knotts,

Yeah tried going direct with a good cable when it first happened at the gig, but the volume was still way down.

I've just tested again today and typically.. it's working fine. I'm so confused!

 

[domct203]

Is there anything different about the rig today vs the gig (fx loop setting, power conditioner, etc)?

What are you using for preamp tubes? V3 and V5 in the Roadster are cathode follower positions and certain tubes can cause volume issues.

Avoid any New Sensor brand (Electro-Harmonix (also "Mesa Russian-2"), Tung-Sol reissue, Sovtek (also Mesa "Russian-1), Mullard reissue) in those positions.

The current Mesa 12AX7 is a relabeled JJ and is fine in those positions as well as any Chinese brand (Shuguang/Penta Labs).

HTH,
Dom

 

[knotts]

If it was at a venue, it could have been a power issue. I've seen some bad wiring at bars, with black marks all around the outlets along with the old two prong input. If it happens again, I agree with Dom in that it may be a preamp tube.

 

[RPercival]

i suggest pulling the amp from the case, playing it, and tapping on tubes with a pencil. If that doesn't do it, grab a sock (so you don't burn yourself) and wiggle the tubes around. If you've changed tubes a lot, the tube sockets can lose tension and a bit of a jar can break contact.