halved the playback rate to 22k and switched to "LQ resampling" in winamp VGMPlay plugin (in_vgm)
mega drive vgm playback sounds a bit dirtier now, probably more accurate to the real machine. been too long since i heard real hardware...
i've been reading about a low-pass filter being essential to perfecting that model 1 sound but i'm not sure that's emulated here