I'm at my wits' end trying to get the tone stack on this amp done right. I bought a '77 Fender Musicmaster Bass Amp in September. After reading on this forum and others about the Harvard tone stack mod, I took it to my tech in November. In early December I got it back, plugged it in and there was a big leap/jump in tone and volume when rolling up the tone knob (I think around 4). Clearly the tech had not fully tested it out with a guitar after making the mod. Took it back in early December. Just got it back today. While there is no longer any big jump when rolling up the tone knob, now when the tone knob is all the way down the amp is not dark--certainly not as dark as the amp should be with the tone knob at 0. Just wondering if someone might be willing to walk me through checking out what the tech did and possibly fixing this myself. If so, please send a PM, or if you're interested in sharing on here, great. I could take some pics of the chassis if that would help. For all I know the tech didn't even make the proper Harvard mod.