Did you end up getting the FX 01?
I am another happy user. I really can't believe the sound and build quality of this little preamp.
I use one in my very good vinyl system - as a volume attenuator for the SS Nikko amp which powers some Tannoy woofers, so I can match volume with the tube-powered planar mids and ribbon tweeters. I upgraded the power supply to a $10 12 V, 5 A transformer, and the tubes to GE 5654Ws for $7.
Since I had the stock transformer lying around, I decided to get another FX for my bedroom system. This one is completely stock, and really adds something ("air", detail, a bit more bass, etc) to the CEC belt drive and NAD 3020, powering Goodmans Minister speakers. I have been listening to this system exclusively for the past month.
Great little preamp, highly recommended.