Balanced cables

Stringreen, I, too, own Vandy (Treo's) and am currently using the Atma MP-3 and MX-R amps (non Twenty).
Ralph sold me a set of XLR cables (25foot) to go from the preamp to his MA-1's. They weren't expensive and I find them to be very listenable (no shrillness). 
Perhaps you should give him a call, and get his take on this. His take, if I recall correctly, is that if the equipment is designed properly (like his and Ayre's), then an XLR shouldn't affect sound quality.
Bob

I have an Ayre preamp and an Ayre CDP and the quality of XLR cables most definitely do affect the sound character of my system.

Dave

gdnrbob.....who is Ralph?

Atma-Sphere is Ralph Karsten, http://www.atma-sphere.com/AboutUs

Depending on which amp and speakers I have setup, there is a definite preference for the XLR cable between preamp and amp.  The cable chosen is a different brand between the two setups. The remainder of the systems cabing remains unchanged.

Yikes, that long of a run will be really pricey for a quality cable.  The hard part is there is not a best cable period.  It will take time and a few candidates to find the right one for you and your system.  Maybe the Cable Company has some long runs of different XLRs you can try.

You will get everyone’s version of the best cable, unfortunately that won’t help you one bit.  I won’t tell you mine.

Question, is this a new problem or something that’s been there awhile and finally bothering you to the point of doing something about it?