Preamp Recommendation for First Watt F4


I am planning on building a First Watt F4 because it would be a good learning experience and, by all accounts, it's a great amp in the right system. Can anyone provide specific recommendations for the companion preamp? My guidelines are single ended, 20+db gain, and preferably tubes. Not ideologically opposed to solid-state, but think tubes are better fit in general. My short list:
CJ ET7s2
Aric Mother Load II
Allnic L7000

Thanks
paullb
Aric is great to work with. I have one of his preamps in my secondary system,(The Unlimited),that I purchased new. I had a question regarding the ML II, even though I had purchased used,he still responded within 10 minutes.  

Please tell me about your experiences with the F4 amp driving what speakers and from what line stage.

Many folks are reporting excellent results with the Pass B1 with Korg triode.

I'm currently building one for my F5 amp and to try with other stereos. I'm adding film coupling caps and an external linear power supply but otherwise stock. If I really like it, I'll add remote control volume later.

The first link is for the kit ($299 complete). The second is a lengthy build thread.

It would be interesting to see how much better the line stages the OP lists are than this inexpensive kit when built with decent film coupling caps. The stock electrolytics are 10uf. Recommended film values to keep size down are 0.22uF for the first cap in the signal path, 1uF for the second and around 3.3uF for the output.

B1 with Korg Triode (B1K) Full Kit

B1 with Korg Triode Build Thread