NOS tubes for Aesthetix Calypso


I recently purchased an Aesthetix Calypso. I really like the preamp, however I would like to purchase some NOS tubes for the unit. First priority would be a liquid smooth midrange, second would be soundstaging, third would be frequency extension. I would really appreciate some Calypso owners offering up some experience and suggestions with the NOS tubes. I would also like advice on where to purchase NOS tubes. My system consists of Maggie 3.6r's, 2 Vandersteen 2WQ subs, A SMC modded McCormack DNA-2, Resolution Audio Opus21 cdp, and all Purist Audio cabling. Thank you in advance for all your help.

rhythmace4218
rhythmace4218
Have had serious problems to mount on valves NOS Siemens (1960), the machine goes in protection or if it started emits a strong noise of current from the loudspeakers. As soon as return to normal Tesla or Sovtek, all it returns normal. You have ideas?
What's the average burn rate (i.e. how many hours can the tubes last ) for the Calypso?