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.