audio tubes for Audible Illusions Modulus 3a

Currently own Modulas 3a pre amp can i use mullard 6922 on line stage and electro harmonix 6922 on phono side or do they have to match all together
Not a problem, so long as the channels match on each stage.
AI preamps are very hard on tubes and will use up NOS tubes in very short order. EH tubes are fairly robust as are most of the Russian tubes. If you like the sound of the NOS tubes (who doesn't) be prepared to replace them more often.To answer your original question--I agree with Ncarv.