Bob,
Auditioned the Arc ph7 and it didn't have enough gain for my cartridge. I also tried esoteric's new phonostage, which was very good, but not so good to warrant the high price. The whest ps 30rdt has the gain, it's very quiet, revealing, dynamic, neutral. To my ears there's great synergy with Arc tube gear. The whest also has balanced outs. There's a good review on the whest in Stereo Times.
Erik