If I may ask an additional question, I’m not trying to hijack your thread. Of the NOS Mullard 12AX7 tubes , is there much ( any? ) difference in the sound characteristics of the sound. I just picked up a pair of tube mono blocks and they each take 1 - 12AX7 and 2 - 12AU7’s. I’ve never rolled 12AX7’s but in rolling 12AU7’s I tried a standard Hammond labeled NOS Mullard 12AX7. Thanks, to the Op. Respectfully, Mike B.
