ARC Ref 2 MK 2 Pre w/ Pass X-600 monos?

Doesn't make sense. The ARC, if anything, provides an extra boost to the bottom end.

I second the LS5 mkll. I never put mine up against the Ref 2 but, I did almost make the mistake of switching it for the Ref 1. Thank goodness I auditioned the Ref 1 for a week first. The balanced only inputs are a minor annoyance but, Cardas adapters take care of that.

I have had my Calypso for 3 months and it has performed flawlessly. I have never replaced any tubes nor do I feel the need to do any tube rolling.

I have ARC REF2 (original, MKI) to match X-600's instead. There is no problem with the impedance matching. The matching rate is quite healthy at 55 (X-600/REF 2 = 22k/0.4 [XLR] = 55). I like this combo because REF2 could add a bit more sweetness/warmness to the top end which is IMO the relative weakness of X-600's comparing to my previous Pass Aleph's. ARC REF2 + X-600's combo presents a pretty balanced - warm, sweet, dynamic and detail sounding. And also, it should be able to drive any kind of speakers...

Thanks for all of your comments/suggestions. I will look into the LS5 MK II as recommended.

I hate to say it but my experience with the Calypso has been very unsatisfactory. It sounded good when it worked properly--and customer service was very responsive--but after my third set of tubes I can't live with it anymore. Even on its good days I found it kind of noisey and began to miss the Accuphase CL-2800 I had demoed for a few weeks. I have decided to stay with tubes however and I think I'll give the ARC products a try.

Meisterkleef brought up an interesting point though--perhaps it is my Khorus MK II that is anemic. They are absolutely fantastic with accoustic music and vocals--strings and the female voice in particular. Piano though doesn't have the livliness and percussive impact I have heard on other systems. Same problem with bass and percussion on rock CD's/SACD's. Sounds "boxy" and the mid range seems compressed or closed. The bass seems muted. I understand that most rock recordings are poorly mixed and the speakers are very revealing... Was wondering if I should add powered subs, but the Talons are supposed to be great with rock recordings. What's going on? I've been staying away from a lot of the music that I love because it just doesn't sound "right" to me--but how much Bocelli and chamber music can a man take?

I have digressed. I'll give the LS5 or Ref 2 a try. If that doesn't work.... I may be in the market for Vandy 5A's! I'll keep you posted.