I've seen that the BH crack is a great amp to pair with the hd 650, but I realized that the bh crack has to be put together/built. If I can purchase an already built version of the bh crack, I'll definitely do that instead. Especially since there is a deal for it right now.
I built my BH Crack in one night while drinking wine with my GF, took about 16 hours total but more like 8-9 hours of actual work. I had all the tools needed so it wasn't too hard to follow instructions which are really good, I had to do some trouble shooting since 2 of my solder joints weren't good and I was getting some static when I first turned it on, drinking and soldering are not good to do together