This is an interesting thread: I also went through 3 pairs of the Sovtek's but I ended up sending the unit back to my dealer. Clearly there is a problem here: why does Aesthetix, who has a great reputation, repeatedly ship this product with inferior or faulty tubes? My first two sets were unlistenable. The 3rd set was good for about a week and then the noise came back. Perhaps I should have experimented with some other tubes, but I lost interest in the unit and returned it. Is there a quality assurance issue with this company or are they just sitting on a large inventory of crappy tubes?
