A friend of mine received s/n 0001/0002 last week. I had a chance to listen to his speakers, which are Soul Superfly, extensively, with a few different amplifiers. The FirstWatt will be fine. That is to say, if you like the FirstWatt F1, you'll like it on Soul. If you don't like the F1, Soul won't make you like it, except for one thing: This is a nominal 16 ohm impedance speaker. Most solid state amps will output less power into this load but also sound smoother.
You can assume any amp that works well with Druid will work well with this. Soul has deeper bass response, and it is more projecting and more vivid than Druid Mk 4-08, but it is the essential Zu holistic tone presentation. Using the some further refinements to the FRD learned from development of the Essence, this speaker has the widest midrange dispersion of any of the Zu single FRD speakers. It also has the best implementation so far of the Griewe cabinet, and now the floor-to-cabinet gap is non-critical, without the complication of the Essence double plinth.
Think super Druid 4-08 in a more compact form, rather than Essence. Forgoing the ribbon tweeter allows Zu to run the FRD at normal Zu efficiency, and the dynamic supertweeter contributes the meatier more musical harmonic information that the ribbon thins. Soul Superfly is a vivid, punchy, neutral and tone-rich speaker that resets your assumptions about how much cash to allocate to power amplification, yet its impedance and efficiency allow some vanishingly cheap amplifiers to make music instead of noise.
My friend has built new a $10K system around a pair of Superfly Soul, and results easily demonstrate it was exactly the right thing to do.
Phil
