There's been a lot of work by a couple people over at SpritesMind in figuring out EXACTLY how the YM2612 REALLY works. As far as I know, the only MD emulator to currently use those results is Regen. Snake has a number of changes he needs to make for his next update to Fusion... among them, changes I made him aware of concerning the 32X PWM audio. The only emulator to currently handle the 32X PWM correctly is Gens/GS r7 with my 32X PWM code patch applied. When I need to test my 32X code under emulation, that's what I normally use since I'm more concerned with the PWM than the FM.