First Watt F7 owners, impressions?

Let's discuss speaker and preamp pairings you have found to work the best and why. I love this amp but maybe haven't been able to get the best out of it yet. 
  • Preamps: DIY Pass B1- great except for dynamic scale and deep bass, of course with no gain I also had to jack the volume a lot more; Manley Shrimp - better slam, more density, 12db gain helps a lot overall a better match. Want to try: microZOTL, Pass x-1
  • Speakers: Gallo 3.1 - easy to drive though only 88db sensitivity, controlled well by the F7, plenty of tuneful bass, plenty of volume using the Shrimp and impressive soundstage; Devore gibbon 8 - just acquired these and am getting used to them, definitely leaner and less bass but I like the midrange and punch a lot, soundstage is excellent too, and their look and footprint appeals. Want to try: Harbeth monitor, Spatial M4, Zu Soul, all of the speakers Srajan of 6 moons owns!
So far I agree with all the reviews of this amp I've read, their observations coincide with mine. Do you find the same?
I'm interested in hearing about the F7. The input impedance spec of 10kHz makes it hard to find a suitable match with a tube preamp.

Have you compared the F7 with the F6?
I have not, I rely on 6moons for those comparisons. I have had the F4 and Aleph 30, and prefer this to both. The Shrimp preamp I use is a good match, very low output impedance. There are others too but I agree it takes some looking. Worth the effort though! 
I called Reno HiFi regarding the F6, F7 and was told that they probably couldn't drive my Gallo Classico floorstanders (88dB, 4 ohm). How well does the F7 push the bass of your Gallo 3.1's?
For more info regarding the difference between the J2 & F7 (and the Pass SIT-1 mono blocks), check out John Richardson's Part Time Audiophile write up on all three amps with 3 different loudspeakers including Zu's Druid Mk. V, ATC's SCM 19 version 2 and my own Fritz Carbon 7SE's.

Also, check out the Stereophile review by Herb Reichert of the J2 with half a dozen loudspeakers at

Lowrider, the F7 controls the bass very well, no doubt due to the excellent damping factor. Mark is apt to focus on the sensitivity level rather then the impedance curve, and the gallos are easy to drive. See Srajan's response to my question about the pairing (in his feedback section). He found the F7 capable of driving several speakers well that "on paper" it shouldn't have been able to.

Fritzspeaks, the Carbon 7SE is on my list to try! Partly due to that review. What amplification are you using with those? 

Thanks, Ron. Good info.