Crack has been finished and running for a couple of days now. Sounds amazing. I was blown away as to how fantastic the Beyer 990's sound on Crack :-) Thats with the included Sovtek 12au7.
It's bone stock with the exception of replacing the included cement resitors with Mills and a Blue Velvet pot instead of the Alpha. No need at all for any pre-attenuation of the pot. Ive been using mostly between 11 0'clock and 2 O'clock on the pot which seems to be about perfect with my source and both cans Ive tried so far. I have no upgrade itch at the moment other than to do some tube rolling, Im enjoying the tunes. I have quite a few 12AU7's in the house. Mostly USA. I tried a GE last night which was a nice improvement mids and treble. The Sovtek does seem to have a bit more bass. Ive plenty of tubes to try including a couple of 6AS7's. I have a pair of M-Audio Q40's that are 64 ohms and sound great on Crack as well. Im looking forward to trying the old AKG 600 ohm 141's when they get back from AKG service.
Really enjoying the new recliner-side headphone system !!!
Thank you to the Bottlehead gang for offering this fantastic sounding and very affordable kit. And everyone for their patience in helping me with questions and learning me somt'in in the process, especially Jrebman, Grainger and Paul J.