Best budget preamp for Aragon 8008bb and Thiel 3.6

Don't know; never heard the bottlehead unit. If you are into kits then that might be a way to go. The cj performed very well in my system (so much so that I went further up the cj food chain). And at the price point of the PV-10 you can get your money out of it if you don't like it. The bottlehead is questionable if you buy it build it and don't like it you will probably lose money on it.

The tubes on the PV-10 are easy to change and are inexpensive. Just take the top cover off and there they are in all their glory. You can also play around with different tubes (called tube rolling) to get a different sonic signiture (fun).

(IMO) The Thiels really sound nice with a tubed pre and ss amp combination.

Forgot to mentioned that I actually had a vary similar system about 9 yrs ago. CJ PV10A -> Aragon 4004 mk2 -> Thiel 3.6.

Great sound stage. Not the most transparent sounding system I have owned but the music is all there.

Going with some NOS for CJ PV10A would be great. There are lots of used NOS tubes for sale that still have long life in them and they are about the same or slightly more expensive than current production tubes.

You can't go wrong with the Bottlehead Foreplay. They have an excellent reputation, a strong following and good resale value.

Cary AE-3's come up from time to time for $300-350 used. They have a tiny footprint and sound very nice. I had one for a while.

The Eastern Electric MiniMax gets rave reviews and goes for $500-600 used. Six Moons reviewed it a few years ago.

Personally, I don't care for passive preamps matched with solid state amps. If you had a tube amp, I'd second the Promitheus suggestion in a heartbeat. For $300 used, they're impossible to beat.

I use a Bryston BP25 with my Aragon 8008bb with great synergy.