Preamp for First Watt F7

@coaster86 

I think the Van Alstine RB10 (which I have) could be a good pairing for the F7 but the F7 has a 10kΩ input impedance. 
If you buy a new one from Frank , he can make an adjustment to one of the preamp outs to be a super low output impedance that will drive the F7 nicely.  I think it drops the output impedance from something like 2200Ω to 47Ω.

@j_andrews -never thought if asking the manufacturer to adjust the impedance to better match - thanks for the tip

Thanks for your feedback. Someone messaged me this article which talks about the synergy of the MicroZotl with the FirstWatt F7. Figured I would share it here. The output impedance I believe is single digit ohms. Worth a shot, I'll probably start here if I can find a used one.

When I had an F7 I used the Manley Shrimp (good impedance match and adds tubes) and the wyred4sound stp-se level 2 (so I could hear the amp characteristics). Both worked well, I think the tubes added something nice/worthwhile. I had the MZ2 mentioned above, but not with the F7 - any one of those 3 will be a lot of fun, for the price (used) I’d start with the LTA MZ2. Enjoy!

You’ve gotten some excellent suggestions. I owned a Van Alstine T8 and enjoyed it.
A couple more: Dehavilland Ultraverve- impedance matching may be an issue but the cathode follower design helps. I used it within Bryston, Van Alstine, Akitika and pass amp camp diy monos
For solid state a used Bryston BP 20/25/26-tranparent and built like tanks 

Out of the box but if you’re handy Akitika PR 102- I built one and the sound is really good. You can also purchase assembled. The flexibility and control are bonuses to the sound.