The Amp Garage

first I like to thank you guys for giving me your time. I went with 4.7k instead of the 100 ohm9 and changed the FBR from 820 ohms to100k. This made the presence pot work but killed the tone and volume of the amp(volume cut in half). zi'll go over my work again and make sure I have it right. thanks ...

http://ampwares.com/schematics/bassman_aa864.pdf I've tried a 25k linear pot off the feedback resitor, to ground ( different values .1, .68,) . My problem is, I only hear the presence come on, at the very end of the pots taper. It is more or less like, an on of switch, with no in-between sound? I al...