Mcintosh c2300 preamp tube question

I have a pair of vintage RCAs on the way...12ax7a. I am using JAN Phillips Black Sable 5751s now after a week with Tung Sol 12ax7a tubes. I like the Tungs better.

Cant wait for the vintage (early 1960's) RCAs to arrive!

All of the above improved sound greatly over stock Mac 12ax7a.

BTW: the amps are 501s.

I have vintage RCA 12ax7a replacements on the way. i am currently trying JAN Phillips 5751 tubes now.

I absolutely hated the stock line stage McIntosh tubes in My C220. I purchased some Black Sable Mullard Blackburn UK made ECC83/12AX7's from a fellow Audiogoner and was still unhappy. I had scored some 1968 Raytheon 5751's windmill getter tubes a few years back for my Dynaco Pas 4 (Panor Corp) and decided to try them in the C220. WOW! I've rolled some 12AX7 tele's and 50's 5751 GE triple mica blacks and I'm thinking the Raytheons are the ONES. Very interested in trying some vintage Tung Sol 5751's. The more I hear of these 5751 tubes the more I seem to prefer them over 12AX7. They just seem cleaner and tighten everything up. I'll continue trying the 12AX7'S from my cache with serious listening attention, but for now those Raytheons really do kick some ass in a Mcintosh C220!!