I have the CAD 120's with cardas caps. If you can get a Cary pre like the slp 98 the gain is enough, so that you will not need the MarkII upgrade. It is one hell of an amp. I'm using Gold Lions KT88's but the stock tubes sound really good too. Not sure about Sonus Faber, but the amp worked very nicely with Klipsch, Linn Majik 140's and with the L707 Lipinski speakers I have now. I hope you can get the amp. Best of luck.