I have an amp (not built by me) and I don't have a schematic, but it's obviously based on 5F1/5F2A type of circuit. Controls are tone, vol, master. Tons of gain, 2 x 12AX7, 1 x 6V6. The tone control is wired backwards: the higher the tone is the bassier / less bright it is. The tone pot caps were the typical value, don't remember exactly what they are. When playing loud, the tone control has very narrow useable area: tone at 8-10 is good, 1-7 too bright/thin/gainy. And this is with humbuckers! How to modify those tone pot caps to get more usefull sounds? Which one to make smaller value, which larger? The brightness can be reduced a lot and it would be cool option to have even darker/less gainier tones than now. With single coils the amp is way too bright. Thanks.