NOS Tubes for Rogue Tempest II

Hi Sam - I don't have a Tempest, but a pair of M180s, and have been experimenting with the 12AX7 tubes recently. I called Rogue before starting and asked for some tube recommendations, and they were very helpful.

I tried NOS Mullard CV4004 and my impression is that it is warm and laid back. I also tried NOS Sylvania 5751 and prefer it to the Mullard - it is clearer and seems to have more life to it (in my system), and it throws a nice soundstage.

I also tried a new production Tung-Sol for kicks and giggles and actually found it to be better than I'd expected (this is the first new production tube I've tried). It is a different sound than the Mullard and Sylvania - much brighter with crisper bass, overall just more "concise". Not bad for the money though, IMHO.

I've also got some NOS Telefunkens en route - I'm curious to see how they work out.

Good luck!

Right on - I believe those GEs are what my amps were supplied with (are they the ones marked with 5 stars?). I prefer them over the Mullard, but prefer the Sylvanias over the GEs (though it's not a drastic difference there, to my ears).

Yeah when I bought the amps the dealer requested NOS tubes with them, I believe.

I have RCA clear top 12AU7s in my amps now and love them (they were a Rogue recommendation) but I haven't heard a 12AX7 (M180s use 2x12AU7 and 1x12AX7 each). Great, another thing to buy!! ;)

Hey Sam - my Telefunkens 12AX7 arrived today, and I'm liking them a lot.

I've been doing a lot of rolling the past several days (both 12AU7 and 12AX7/5751), but came full circle back to the RCA Clear Top 12AU7As now paired with the Telefunkens - this is a very nice combo. Airy, spacious and more high end sparkle than the Mullards (when paired with the same 12AU7s). I think I still prefer the GE 5 star 5751s to the Telefunkens, and the Telefunkens over the Mullards, but I'm going to stick with this combo for a while.

It's hard to pinpoint differences in 5751 vs. 12AX7 for me, since individual tubes in each genre sound different (like the Mullards/TFs). But I think the 5751s image a bit better for me. Like, center images like vocals are more, well, centered, and there seems to be a bit more width. Not drastic differences though.

One thing I can say though, is I tried some variations with new production tubes (JJ Ecc82 gold pin, bare bones TungSol 12AX7) and that was largely disappointing. I wanted to like something new just for $ reasons, but no dice. The Mullards with the JJs turned out "OK" - not great, not terrible - but after a while listening got boring, so I moved on...

My power tubes are stock - EH KT90s. I've never tried changing them (and there don't seem to be many kinds of KT90s out there, and I need 8 of them so that can get pricey!).