Pass XA Monoblock Amps with Audio Research Preamps

At this point, I am considering the Audio Research LS-27 along with the Pass XP-20 as preamp possibilities. Some of the people who have suggested the Pass XP-20 have told me that I would get tube-like sound without the maintainance of tubes. Other reviews I have read about the Pass indicate it is on the neutral side. I would think that the Audio Research LS-27 would effect my system with much more of a tube like sound and the Pass might be better in the bass area but without hearing either of them, its just speculation.

I tend to think both would be a good match with the Pass XA100.5 Monos that I own.

If the input impedance of the amp is less than 30K, ARC preamps will tend to be bass-shy. There was a thread about this just a few months ago.

A tubed preamp can be a rewarding combination with your amp. I've seen definitive statements on this website that:

1) AR Ref preamps are not a good match with Pass XA.5 series.

2) AR Ref preamps are a great match with Pass XA.5 series.

My interpretation would be to proceed cautiously and critically, and seek a price where you could resell if the sound was not superior in all regards. Do not accept mushy bass or a rolled treble for some midrange bloom.

I do think it is important to use the balanced connection on the amps. I would be reluctant to use a tubed preamp that people charactarize as smooth and musical. Not that those types of preamps are bad, but they may be too much of a 'good' thing with the Pass. My opinion would be to seek a highly resolving preamp with good frequency extension.

I can give a firm recommendation that the BAT Rex and Pass XA.5 is a great combination. Really, really.

Just so you know ARC preamps are not really balanced according to the official balanced guidelines they do offer balanced type connectors. As a result the ARC preamps don't work well with low impedence amplifiers like many solid state amps are. I'm not sure about Pass. But I would consult with both companies before I mixed them just to be sure. Impedence mismatches are more common than you might think and are sometimes the reason why we think some components may not sound good.

Give Reno HiFi a call and ask for their thoughts. I have a Ref 3 with a pass labs 350.5 and it works well in my system. Good Luck.