The advantage of 6922's is that they last a long time, 10,000 hours. To get rid of some of the microphonics you could try tube dampeners. Even the little rubber rings will help. I'd stay away from the new mullard remakes out there. I just saw the Jan's really reasonably priced: Try www.partsconnexion.com or tubesandmore.com or echohifi.com or upscaleaudio.
Personally, I love my Golden Dragons and have Jan's as back-ups.
Personally, I love my Golden Dragons and have Jan's as back-ups.