I have the Aesthetix Janus, and in my system, I have purchased a brand new stock set of tubes from Aesthetix, and I've also purchased NOS Amperex and RCA tubes from Andy at Vintage Tube Services. I will say that for the phono section, I liked the sound of both sets just fine. For the Calypso portion, however, the stock tubes sound rolled off and therefore dead except at quite loud levels. The VTS tubes sound much better.