Conclusion...from brief comparison
I do enjoy both the J3 and the HM601 and from a sound perspective the HM601 is the superior product. It just has better resolution and sounds wonderful. It is not the flattest source as I suspect there is something going on in the treble from listening. I know there are graphs somewhere but I can't remember what they look like. The J3 is a nice dap as well however doesn't quite do what the 601 can do on a sound perspective. I
If you look at the J3 and 601 as the whole package including battery life, size and UI the result will be different depending on what you value. If you care only about getting the best sound then the 601 is the choice. If you want good UI, battery and a smaller size then the J3 may be a better choice but if given the choice I'd pick the 601 and I pretty much have since the J3 has been regulated to being stored in my bag as a backup in case the 601 battery dies on me. My 601 battery died on me before I left the house (well my fault as I left it on overnight) and I had to listen to the J3 today. I was thinking during my commute that I miss the 601. As much as I like the J3 which I do it's no 601.
