Hi again guys!
Sorry, I have not answered to your questions but I have had short vacation
Normally ART Tube MP should use pair of TL1072's. We changed them with Burr Brown OPA 2604 (approx. 5$ each). They seems to fit very well. Then we changed that original Chinese tube to JJ 12AX7 which made ART one degree better also. If you want less gain just put 12AT7 and you are set.
I am very pleased with these little cheap boxes - they have their uses
with respect,
AaPee