Preamp - Ayre vs. Audio Research


If anyone has heard both the Audio Research Reference 6 and the Ayre KX-R Twenty preamp, please describe the differences in their sound.

I recently settled on a D'Agostino Momentum S-250 amplifier. I compared it to a pair of Ayre MX-R Twenties, and my report can be found on a thread called D'Agostino vs Ayre. 

Unfortunately, the Momentum preamp does not offer a line out option, and I want that for headphone amp operation. So, I am considering the AR or Ayre preamp options. Thoughts?
imgoodwithtools
I purchased an Audio Research Reference 6 this morning, slightly used with 330 hours. I will compare it to my Ayre KX-R Twenty preamp and report back, likely in about a month.
I look forward in reading about your review- imgoodwithtools-

you certainly own an interesting combo.  What other gear is in your system?

Happy Listening!
I bought the AR Ref 6 on Audiogon just this morning from an individual. I've dealt with about six dealers just this past 18 months. JS Audio, Crescendo, Audio Alternative, Galen Carol Audio, Scott Walker Audio, and the Cable Company.
My current system is a PS Audio Perfectwave transport feeding a Berkeley Alpha Reference 2 processor thru Synergistic Research Galileo LE AES/XLR digital interconnect, or an Esoteric SACD player. Balanced interconnects are Audioquest WEL Signature. Present preamp is an Ayre KX-R Twenty that I plan to compare to the Audio Research Reference 6. Quite often I run the Berkeley direct, with no preamp. Its Amazing. Amp is a D'Agostino Momentum S-250 powering Wilson Alexia loudspeakers. Cables are Synergistic Research Galileo LE.