Well i've largely solved the problem. Anyone who has one of these amps has to understand how the effects loop and hard bypass work. If you have the hard bypass loop swictched on at the back then the volume controls no longer respond and you have to use the master volumes to get your sound levels. The solo function will not work.
So, naturally you switch the loop in on and operate it with the output and solo volume buttons. Brilliant. But you must set the level of the "send level" dial on the back. At least set it to normal.
It's simple but i didnt know about that. For years i've complained of differing performance levels at gigs and i had the right hump with it some nights. Anyway, solved. Just got to set the dial on the back to normal.
If you crank it up you get a real volume boost. I realise that some gigs it would have been low and others normal or high. I must have inadvertantly moved ial in transit from home to gigs. It was pot luck whether it would be in the correct position or not. Hence, differing performance levels. I thought i was going mad.
Ultimately you have to know what you are doing with the loop in and hard bypass settings. I have blindly gigged in hard bypass and loop in without realising the difference between the settings. Consequently my amp has been performing differently gig to gig and i could not work out why.
Sorted now. Doh!
