I ordered a Crack in April and got it in May;,within a week I was up and running, There were a few issues- one joint I missed soldering and a few joints I reflowed. That took care of any snap crackle and pops. Made my way over to some NOS tubes- a 5998 and a Mullard 12au7. Added Cardas headphone cable to my HD600's.
I'm lead to believe that there is better but as far as I'm concerned I've got the finest personal listening setup I have as yet to experience.
A friend spent $1000 on a pair of headphones alone. My total investment, including wood finishing products, is perhaps $40* more than what my friend paid for his headphones, which I don't think are exceptional. * add $20 for the fancy wire stripper I treated myself to- but I've already used that tool for other things.
Truly feeling some Crack love and dig the whole DIY part
Crack/Speedball, SEX 2.1/C4S, Bryston BHA-1
Sennheiser HD600/Cardas cable, Beyerdynamic T1 2nd Gen, Hifimam HE560/Hifiman balanced cable