@big_greg
As good as it sounds in my system, I’m still auditioning other tubes.
For now I have my Sylvania 1950s vintage 6SN7GTB chrome domes in. They are really nice sounding all around, but don’t have the bass of the 1578 and maybe a little less detail. They are very "neutral" sounding and do everything right, but I liked the way the 1578’s added more detail and texture to the bass.The Sylvania GTB is an underrated tube. I’m using them in the driver/phase inverter position. Excellent midrange, smooth highs with wide soundstaging. A laid-back sound which doesn’t have the typical Sylvania voicing.
As good as it sounds in my system, I’m still auditioning other tubes.