Rogue M-150

Thanks, I have some NOS tung Sol 5751. I will give those a try.

Kept coming back to the stock Sovetek long plates in the 12ax7 slots on the Zeus. Tried telefunken's and a couple other flavors, none were bad, the long plates just seem to give a crisp and tight sound to the bottom that works well in my system and I don't feel that they are lacking elsewhere.
If your system sounds better in triode mode (mine doesn't) you might also like the somewhat more refined sound of the tele's.
Nobody has tried the Mullard 12ax7 copies from groove tube?

I've had excellent results with the Ei gold 12ax7 and 12au7s in the driver and phase inverter positions, german, telefunken or siemens in the first stage.

I have recently replaced my Sovteks 12AX7LPS with the new Groove Tubes 12AX7 Mullard replicas on my Tempest II.
The GT are extremely quiet, the mids are warmer, and you get a more 3D-like soundstage, the treble is more smooth and airy, but I might have lost a bit of bass.
All-in-all highly recommended !

Iaxelrod-
How long have you been using the GT's? I have a Tempest II as well & just got a pair of the GT's today. Out of the box the seemed nice but I did notice not as much bass compared to the LPS's and some NOS Mullard box-plates I have been using.