Always figured this combo couldn't do the musical tube OD. Happened upon this tweak and it sounds fantastic IMO, so figured I'd pass it along in case anyone else on here is getting frustrated with theirs. Fender P --> Passive switch Gain: between 1:00 and 3:00 Bass: noon Mid: at or near full CW Treble: at or near Full CCW Then use the Para EQ to fit the room. I'll usually use the Low band to roll off some rumbly low freqs. And with a P-bass I'll usually bump ~3db at ~250hz. Warm tubey goodness, to my ear at least.