Yes the deep mod is what you're looking for.
I am about to sell my 50/50 and buy a 20/20 because it will shave at least 15 lbs off the weight of my rack case. I plan on doing the deep mod myself. This is from a review of the 20/20 on Harmony Central:
When I first got the amp, I was very dissapointed. It was very middy and lacked bottom end. At times, I'd turn around to re-check my bass/mid settings on the preamp. very frustrating. Nothing I did improved the tone. After 48 hours, I was ready to return the stupid thing. It just sounded like a low fi transistor radio.
I did a bit of research on the web and found out about this "deep" mod. The 20/20 has a high pass filter that cuts the lower bass frequencies. This is the same idea as the TS-9 pedal by Ibanez but on the 20/20, the bass cut is pretty big. The mod is pretty simple and being good in electronics, I performed the mod (simply removed C1/C3 capacitors for chA and chB respectively).
Doing the mod completely transformed the amp. The frequency response is now "normal" and not modified at the input with the filtering crap. What a difference. The amp is now alive and playing clean chords on my Strat on the neck pickup sounds like it should.
