You mighy want to try 5751s (Sylvania Gold pins are the holy grail of 5751s but my GE 5 star's work beautifully) in place of the 12AX7s they have slightly lower gain but some how brought more air and soundstage to my system. Mullard 10Ms may indeed be the best tube but even if you can afford such an expensive preamp the price of these tubes is absurd and really verges on the ridiculous. The brightest sound may in fact be found in a very humble tube such as a current production JJ or Ei. If your Calypso is new it already has that. You might want to see if rolling the 6922s to a Siemans or Mullard 2493 not 2492 does the trick. In general the manufacturer uses a tube it can getrepeatedly and believe it or not even with expensive gear cheaply so I tend to ignore their voicing experiments, despite the fact that it is counterintuitive. I have seen far too many fine pieces of equipment use Sovteks which I have yet to hear even halfway decent in my view they are terrible tubes. I don't get it.
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