Audio Research PH5 Cartridge reccomendations

I'm seeking the opinions of others who have the PH5 or, perhaps, other tube phono stages. I recently got a PH5 to mate to my new VTL 6.5. I got it as a barely used demo. Even with lots of warm up, I felt distressed that the sound coming from My Linn LP12 and Clearaudio Virtuoso Wood cartridge was a bit too rolled off and not impressively dynamic at all.Yes, I did do the proper cartridge impedance matching.
After stretching my already stretched budget, I decided to replace the original ARC-supplied 6922 tubes (Sov Tech it seems with a set of NOS Mullard/British made 6922s from the early '60s. Wow! the difference was amazing and non subtle. After a day or two of break-in my phono section has a beautiful warm balance and dynamics up the wazoo.
My question is if anyone else has had a similar experience with tube rolling in the PH5. Also, among my concerns at first was that my Clearaudio cartridge may have been a poor match. With the original tubes, there was way too much gain in the PH5. I thought maybe the cartridge had too much output for that preamp. With the new tubes, the gain seems to be about 20% less and the music really blooms. All comments welcome.
I have tubed rolled with a # of nos tubes in my ph5 currently have seimens in. the phono pre responds to nos tubes more then many tube pre amps. I am using a ZYX airy 3s which I feel is one of the sweet sounding cartridge's
Pscialli, I use the PH5 with stock tubes with a sumiko blackbird matched at 47K. There is alot of gain but it is not rolled off in the least, it is also a very dynamic combination. The highs are absolutely pristine with very nice detailed bottom end. I only have about 50 hours or so on it so I am still breaking in the cartridge and preamp. Glad to hear you snapped yours into place with some mullards. I use them in my CJ line stage 6GK5's on occassion. They have a nice rich midrange but aren't quite as transparant as the original stock tubes...sylvania/GE combination.
I use a PH5 with stock tubes (I thought they were Electro Harmonix but I could be wrong, I didn't even look when I installed them) and an Ortofon Kontrapunkt B. I left aside the Ortofon T-20 Mk ii transformer I was using previously and, while on the low side, the gain is sufficient and the noise low. I trust that the tubes ARC uses are as good as can be obtained in new tubes. The whole issue of NOS tubes can open a Pandora's box and I will face it down the road when the stock tubes start showing signs of age. At this point I am satisfied. I so hear small differences with the loading and prefer the 100 ohm setting. For me the loading is set-and-forget, so I don't see much use to having those controls on the remote. My only recommendation: get a cart with more gain than the Kontra B.