Quote Originally Posted by fuksxyz
The sound of BW 685 is worse ( for me ) when using the Tube Buffer, I can say worse becuase the high frequency is cut off too much. So I don't think the Tube Buffer improve the sound of BW 685. Meanwhile the Tube Buffer helps the MA by cutting off the high a little bit, although I can still hear that the MA sound is still a little bit bright, but I can accept it now.
BTW, what is YBA?
YBA is a french brand:

http://www.yba.fr/uk/YBA_present.php

I've heard the MA's combined with the Audio Refinement Complete Integrated Amp & CD Player (Audio Refinement is made by YBA)....

But the best setup I heard was definitely the Musical Fidelity X-T100 Integrated, X-Ray V8 CD & Monitor Audio GS20...... It was in a small room, just 11' by 11', but it did everything right and was definitely not bright... I didn't notice any special room treatments... just a carpet and a leather sofa....

Since you find that the MF Tube Buffer helps tame the MAs but hurts the B&Ws, then your issue is quite possibly just system synergy after-all....

If you eventually want to change your amp and cd player.... you can try some of MF's other tubed Gear... The X-T100, A1008 & KW550 Integrateds are all Tubed... while the X-Dac V8, A5.5, A1008 & KW Dacs/CD players are also tubed....