Volume issue

[daz]

this is a cathode biased EL34 build that has a high gain pre. It's one a gave to a friend and i have one almost exactly like it myself. i never had any problems,but he leant his to a guy who used it to reherse with his band. When he returned it he said it lost volume at one point. i have it here now and sure enough after about 10:00 or so on the master it stops getting louder and just gets more overdriven. The volume is quite low.

I checked voltages everywhere i thought to and checked every solder joint. I also tried different tunes and checked many components like screen resistors, cathode caps and resistors. What else can i do w/o a scope.....what else to check that could cause this?

[Alex R]

If it's thAT nice design I saw posted here - sure the switch that lifts the el34 cathode bypass caps from ground is working right?

[daz]

Thanks, but thats not it.