It’s always subjective, and every tube behaves a bit differently in each circuit, but I’m finding the Tung Sol 7581A (a 6L6 variant) sounds superb in my Dyna/VTA 70s. I’ve run a few EL34s, and I really liked the Gold Lion KT66, but have been absolutely thrilled with the musicality, clarity, and texture the 7581As produce, along with 12BH7a driver tubes in these amps. Best of all, they’re not super expensive.
KT88 vs 6550 vs ? for warm midrange - using Cronos Mag lll
I've been listening to an ST70 with EL34 Tubes & really enjoy the Sound .
Using the Cronos with KT120's it's a different sound / feel - sounds wonderful but seems either more balance / neutral overall . Maybe more lower end but not as sweet in mid range as the 34's
34's in the cronos is possible but not really advisable [ too much current into tubes - 1/2 the life span even with proper biasing ]
I've been running the amp in Triode mode and seem to prefer sound . Listening levels are moderate / low avg 75 db
I'm good with the kt120's but maybe another tube would bring more mids to the game
* Note - I have changed All the preamp tube to NOS - It has been a significant improvement !- Telefunken is at center 12au7 , flanked by RCA clear tops , 2 GE ax7 's
Any suggestions for power tubes is most welcome - Rogue audio is shipping kt88's in lieu of the 120's [ for yrs due to war etc.]
what's gained or lost when changing from the 120's ?
forgot - Primary Speakers - Dynaudio special 40's , primary source is Vinyl
Thanks