Lonestar Classic volume drop/ v3 preamp tube

Hi, Lonestar noob here. I bought a used 100/50/10w version a few months ago and I love it. I was previously a confirmed Marshall man, but found myself using clean tones more and more. Together with a Xotic BB and a JHS Charlie Brown I can get close to the best of my Marshalls together with the wonderful clean and milder overdrive that the LS delivers.

However, I experienced a problem at a gig last week whereby the overall volume dropped significantly. Not suddenly, it occurred when i switched the amp on for the soundcheck. No lead, pedal, moved knob or switch problems, I assume (d) that it was a tube problem. I got through the gig as the tone was fine and we were mic'd up.

Doing some research online, I've found that this is not a unique problem and should be resolved by replacing one or more preamp tubes. However, I also found reference to using a Chinese made 12aX7 in V3, though this advice did appear to be a few years old.

I can't see any difference in the (Mesa) tubes that are installed and also, though I can buy Mesa tubes here in the UK, I can't find anywhere that specifies whether they're Chinese or Russian made.

So, my questions are:

1- is the volume drop indeed likely to be a preamp tube issue?
2- is the 'Chinese in V3' advice still correct/ relevant?
3- if so, can anyone tell me where I can obtain such a tube, pref in the UK

Thanks.

Greetings

I recently had the volume drop issue with my Matchless Indy. Turned out to be the rectifier valve, which when replaced, fixed the problem. Worth a look, as well as power / preamp valve tests. Apparently the phase inverter can cause vol drops also

I buy all my valves from Watford Valves - check out their website. Call Derek, and he will fix you up. He is switched on, and understands what bias range you need for Mesa's assuming you buy power valves from him. I think he owns a LSC but can't remember exactly

Where are you in the UK?

Check the effects loop too. Put a cord in the send/return jacks.