this is half of the neccessary procedure to perform a "stealth" mod of the t-amp. you remove R01 and R02 (other side) and bridge C3 and C4 with solder.

the other half is sneaking some higher value (and in my case not much higher quality, though i will fix that) capacitors, before that whole circut. I used 2.2 micro farad caps, the unit should now measure without bass rolloff, it sure sounds that way.