It looks like this is unsolved. I am a relatively new MPC One user running MPC 2.9. Love the machine in general, lot of fun. However as noted in the thread. The MPC cannot record audio when synced as a slave ( I haven't been able to have it record midi typed from the pads or my controller either when in sync mode). I have tested this with a couple of sequencers. Pressing the record button turns the record function for the track off. Initially I had assumed it was something in the Midi Clock stream, a command or something. My initial test was syncing to an sDrum guitar pedal and this worked fine ( later with another device), just cannot record audio on mpc. Nothing in the manual in the sections on MTC or MMC or under the audio recording section ( the logical places). I have a video of the issue at:
https://www.youtube.com/watch?v=qHI8GnwmExsIf anyone has a work around, I'd love to hear it. I guess from here it is an email to Akai.....
Thanks for taking the time.
FYI, the timing in the video drifts because I was trying various sequencers to see if the problem lay with the master device. I think I left a bpm change in the middle of the master sequence and it caused havoc in the MPC timing.