Sonus Faber Stradivari amp: X600.5 or X1000.5 ?

I agree with Raquel for the most part , some bigger amps loose finesse ect , but some mid efficient speakers come to life with lots of power , not so much watts as current . You said you listened to the X350 in your system , it's twice the watts of the XA160 , that should give you an idea if the XA160 will be sufficient in your situation . There is an XA200 if you really want to get serious . Don't forget to take into account the heat that all these babies give off .

Raquel,
Well stated words of wisdom, but only if genuine music quality is the objective as opposed to spectacular Hifi. I`ve come to belive that the advent of inefficient speakers has been counter productive for the persuit of natural sound. It forces one down the path of ever bigger and more complex amplifiers to drive them.

Charles1Dad:

I see that you are running Coincidents - I recently put Total Victory IV's into my system and am very happy with them.

Johnb30:

The Pass amps are very good, but for a lot less money, the Parasound JC-1 monos are a very good sounding high-powered amp. They are also fully differential balanced and should work well with the ARC Ref 3 preamp.

Again, if you want an extremely powerful amp just so you can occasionally listen to rock and roll, you are going to suffer when you are not listening to extremely loud music. And the Strads can go loud and can handle some power, but they are not big Wilsons and should not be driven extremely hard. If you really

Raquel:

What do you mean by "you are going to suffer when you are not listening to extremely loud music" ? If i'm listening to normal levels i should be on class A up to 80 watts.
It is not the same thing as haveing XA160.5 ?

Check the specs of the Pass amps. I think the X350.5 has about the same current as the XA100.5. The XA100.5 also has more class A watts and doubles output as impedance is halved, so 200 watts at 4 ohms. I would stretch for the biggest XA.5 you can afford, BUT your Strads are pretty efficient, though I don't know the impedance, so the XA100.5 should be plenty. Of course, you should listen to be sure.