Albert Porter is a true fount of information on tubimg Aesthetix products, so hopefully he will post here. In the meantime, you might check the archives for threads involving Albert and the Aesthetix IO, as I recall some very detailed information about that unit that might carry over to your line stage.
Aesthetix Calypso, Tuberolling questions?
What results have owners of this preamp had with different tubes used. I'm running stock tubes into a pr. of Parasound JC-1 mono blocks now and the sound is very good. Would like to open up the treble a little if possible without messing up other areas. Any info on what people have tried and to what results would be of great help. Thank you