GT = Groove Tube, 12AX7 tube. Sold in many guitar shops, but used in audio as well. Supposed to sound like a Mullard if I'm correct. I have a couple lying around here that I wasn't too impressed with. Price is right though and you could do a lot worse for new production tubes. Golden Dragon sounded better to me. Of course IMO nothing beats NOS of which I have Mullard, Telefunken and RCAs that I rotate in my phono 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