I had my amp "serviced" professionally buy Amp crazy in Hollywood. The problem was my el-34 tubes I can't remember if they are the pre-amp or power tubes, but that doesn't matter. I had some groove tubes in it, the el34gt's(hardness 7) and it turns out that I had sucked the life out of them and it was time for a new matched set(four). The tech told me that grooves tubes are the same as any other tube and he put in some Telsa el34 and checked every circut. He did a good job other than the tube selection, I think? I could be wrong but to me my amp sound a little lighter, more classic, which is the opposite of The tone I prefer which is exremely heavy yet defined. Anyways now to the problem, My amp sounds great at a lower volume, but once I start to push the volume up, the tone sounds rough and honky, not good. It never sounded like that before? The tech told me That I didn't have to replace the ecc83 tubes ever. Any how, if I replace the ecc83s will it even out my sound at higher volumes? Or is this just normal and should be compensated with a power amp or attenuator? Is there any other reason for the problem?