About the OP BUF of Mont Blanc,
We will choose one as the OP BUF for Mont Blanc, but not sure if you guys have special "feeling" about it.
BUF634, low power consume , warm sound quality. the specification will not as high as LM49600, the THD is about 0.03%
LM49600, special designed for audio, and need almost double power current compare with BUF634, very high specification, the THD is about 0.002%.
BTW, the playtime will be about 15 hours if we use LM49600, and 20 hours if we use BUF634. the charge time is about 7 hours by USB port of PC, or 3 hours by 1.2A USB wall charger. the build battery is a 800mAh/11.1V.