Don't limit yourself to Audio Research. There are many tubed brands (Sonic Frontiers, BAT, deHavilland, Joule, Supratek, Conrad Johnson, Rogue, etc.) which will offer you better performance at comparable pricing. Check out the number of used ARC pieces for sale. Serious audiophiles don't use them very long after hearing the sonic deficiencies in their own systems.
Good luck.
Good luck.