Purpose of CF mod on Pre2?

[hawkinsec]

I thought that I'd start a new thread rather than make this a continuation of my thread in the Coffee Bar.
I've had my Pre2, Phono2 and PS2 for just over a week now. I'm quite happy with the performance of the Phono and although I understand that there are improvements which can be made, there is no desperate need to do so. The Pre2 is a different matter as the sound quality took a dive when it was connected up. There is no hum and gain is not a problem, but all detail,bass and treble are absent. I did wonder if it was my imagination or I something, so I gave it a few days, but decided to have a play this morning.As soon as I got up, I connected the phono2 directly to the power amp. Everything sounded fine. Same story when DAC connected. I started to think about modding the Pre as suggest elsewhere , but on re-reading comments on my own post and others, I get the impression that the purpose of the CF mod is to get rid of the transformers and the tendency to hum. Would this be a pointless mod in my case?