@ericsch the same tube you have WE 396A. just last night i ordered the 6922 to 5670 adapter that is talked about in the orchid tube rolling thread to try out 6922 tubes. ordered an amperex to try out.
@audiewww i left it on for 3 straight weeks and left the music playing through most nights. my theory is it will burn in faster if you give the R2R resistors signal so to keep it physically moving. ime, it sounded great on day 1 (which led me to sell my other two dacs Ares2 and D90MQA) but took a nose dive during the first week. then, it gradually got better during week 2 and 3. also did the chassis tweak which did unstress the mids and highs.