AI is very firm about only using Sovtek 6922 in the pre amp. Many , most tubes do not work in the 3A. So be advised that if you put other tubes old stock etc, you might find them noisey in just a few days. Experment if you must but be careful and prepared for bad results with tubes other than a Sovtec.
Audible Illusions Modulus 3a tubes
I would like to get some advice on replacement tubes. If anyone out there owns or has owned this preamp, I would like your imput. I listen to analog about 75% of the time if that helps. The rest of my system consists of a Bryston 4B NRB amp, Thiel 1.5 speakers, VPI mk 4 turntable, VPI memorial arm, Blue Point Special cart. pioneer CD