Amps for B&W 805 Diamond: Rogue Audio or Krell, Pass labs, ML, Accuphase

The Medusa is a great amp with outstanding detail and 3D imaging/soundstage but I wouldn’t recommend it for the 805s unless you’re willing to do some tube rolling so of the two I’d side with the Krell.  With Pass I’d go with their XA series as it’ll likely play nicer with the diamond tweeter.  The Plinius SA103 is also a great choice, and it has a hi/low bias switch so despite being fully Class A you can leave it powered on or use it for less critical listening purposes without the amp running so hot.  Last recommendation would be the Clayton Audio S100, and if I had the 805s that would be my first choice.  Hope this helps and best of luck. 

Thx soix for your advice a lot. May I ask in detail why Medusa might not suitable for B&W. Rogue Audio is very good for bass so I suppose it is ok with B&W, isn’t it?

The Medusa, while being an excellent amp, definitely leans to the more detailed/revealing end of the sonic spectrum (at least with the stock tubes) and I’d be concerned that this combined with the 805’s likewise very detailed diamond tweeter might make the sound come off as a bit overly bright sounding and potentially fatiguing on extended listening. If you can share what sound characteristics are most important to you and what improvements you’re looking for it would be very helpful in making recommendations better suited to your specific tastes. BTW, what amp are you using now and what’s the rest of the equipment in your system (including interconnects, speaker cables, power cords/conditioning) and what are your listening room dimensions?  The more info you give here the better the recommendations here will be.