Pros: extremely small but amazing sq. volume control is excellent
Cons: not for full sized HP
I received #66; it is a great sounding little amp with great build quality as normal with Justin's work. The volume adjustment is very accurate and provides precise control. Battery life is excellent as well. Unfortunately it's designed for IEMs and it demonstrates why I need to replace the SE530s with something with better low and top end. Picked up a Nano and twag dock; the combination is very small and it does a very good job.
I ended up selling the Slim as I decided I didn't want to go down the J13 route. I'm not a big fan of IEMs to begin with and I'd take a beating if I didn't have a good fitting pair so it wasn't worth the risk to try. I decided to keep the original Pico instead as it can drive full sized cans very well and the difference in sound quality was negligible.