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

I have a X350.5 and love the sound. My friend has a set of X600.5 and a new set of XA160.5s. I would buy a set of XA160.5. Sonically the and power wise the XA160.5s are way better. I have heard a set X1000.5 and they are just OK. The X600.5s sonically sound like the X350.5 but just more powerful. The XA160.5s will be my next amplifier upgrade. The power on the XA160.5 has it where you need it and it sounds about the best I have heard. Realistic, Airy, Open Rich, Powerful, Smooth and just true to the music. I cried the day the XA160.5s left my house but my friend was kind enough to let me try them on my system while he was on vaction. Unfortunately they are a lot more money than my X350.5. Sometimes I think those guys at Pass labs have me hooked on the sound of their products. Sometimes I feel like a junky at a crack house.

The Strads are very sensitive, 92 db.+ and there is therefore no reason to use a high-powered amp with them, unless you listen at extremely loud sound pressure levels, in which event it makes no sense to use Strads (while they go plenty loud, they are primarily a finesse speaker).

It never ceases to amaze me how many people do not know that the vast majority of HIGH-POWERED AMPS SOUND MEDIOCRE. Big amps almost always use global feedback in order to control the circuit, which takes the life and dimensionality out of the music, and they also use dozens of output devices (i.e., lots of transistors or tubes) to achieve high power, which kills transparency and finesse.

More and more solid-state amp makers, from darTZeel, Ayre, the new Rowland, to Sim, as well as Pass (and many, many tube amp makers), no longer use global feedback in their curcuits. If you have really inefficient speakers or listen in a huge room, and you listen loud, then use a big Krell, etc. (even better, sell your inefficient speakers), but if you want your system to make recordings sound much more like real instruments, stay away from big amps and amps that use global feedback. You'll notice that the previous poster is recommending the 160 watt, Class A-biased Pass - not the 350, the 600 or the 1000.

A gentleman I know is using the CJ ART amplifiers with the Strads, and the sound is absolutely amazing! These are the finest tube amplifiers I have ever heard, the CJ amplifiers were able to play quite loudly in his room 30 feet long 20 wide 8 foot ceiling.

The new CJ ART amplifiers are remarkably transparent without any tube bloat and a rich midrange, and stunning dynamics.

If you are in his area, Long Island NY I am sure he would allow you to hear his system.

I agree with Thesoundhouse. If you are set on Pass, I would go with the XA series. I too have the X350.5 and I have the Pass-addiction as well.. My friend had a pair of Amatis and he had been wanting to try the X350.5, but we weren't too keen to hoist the beast over to his house before he moved overseas.

My impression of the Amati in his system (with Einstein preamp + BAT VK-75SE monos) was on the sweet side. So I am not sure Pass would be a good fit. But with a more analytical/neutral preamp like the ARC Ref 3, it should balance out.

My only real experience with the Strads was in a Magnolia Hi-Fi in Seattle where it was driven by all McIntosh stuff, and it didn't sound too good with that combo in that room.

FrankC