Fretless Fiend

Hi It's me again, having got my initial problem sorted I have noticed that when I turn the gain control past 12.0clock there seems to be little difference in the volume and doesn't make any difference to the output level or tone. Volume control increases as expected. Have tried several valves in the V1 slot and they behave exactly the same. Is this normal? Playing as I do, with a clean sound and rarely over-driving I have not noticed this before as the gain is normally set between 9-10. I have a GB shuttle 6 as well and this winds its gain all the way up to max.... which is what I thought I would expect on the Streamliner.

Thanks for the sound advice guys. I swapped the two eq valves around and the problem disappeared completely. Swapped them back and the problem didn't come back. I think reseating them as suggested, plus some very fine emery on the pins did the trick.

AnyValve techies know what this could be?? I have a Genz Benz 900 Streamliner Head which has been my go-to Amp for the last 5 years. Prior to a gig yesterday the first one after a long lay off I noticed that the active mid frequency filter does not appear to be working properly and I I am sometimes getting a mild overdrive distortion when I hit the strings hard. I am familiar the operation of the gain and drive an eq functions and know that the front end isnt working as well as it used to. Could this be a problem with one of the valves going a bit soft? They are around 3 years old and have had moderate usage up until March 2020 and then only used sporadically at low volumes up until yesterday. Thanks Andy