I had one also, along with one of the Alpha amps and the Gamma tuner that matched. I had none of the problems that stagshan mentions, so I think that his is defective in some way(s). Without such problems, its a pretty good preamp, though not as good as the tuner and especially the amp, which are excellent. I got mine at the Goodwill. Regret selling them, but needed the dough at the time.
I occurs to me I also had the first model Alpha preamp for a while. Did not think it was a good, and later saw some reviews suggesting it had a slower risetime than the later models. It wasn't bad, just blah sounding.
Quite a few posters have suggested that Nikko, especially the seperates, are first rate, though usually overlooked, and that would be my opinion also.