I think it's the CMoy. I find the CMoy that I build myself to sound bright and thin. If volume control was not an issue I'd just stick my headphones into a non-portable CD player's jack. I don't understand why people like the CMoy so much (or at all). It sounds worse than most other headphone jacks I've tried, including jacks from CD players, integrated amps, etc. On the other hand, I've since built the META42, and I think that deserves all the raves it gets.