Synchronization between recorders

[tourettes5139]

Hey,

I have a Roland VS-840 GX (decent) and my drummer has a Roland DiscLab (a piece of crap, but hey it works). We recently tried using them together, to give us 16 tracks to work with, instead of the 8 on either one. We recorded 4 tracks of drums on the 840, and a guitar scratch track on the disclab at the same time to save time. We used MMC to control them and to get them to start at the same time. We played together, right with the click, and the clicks were set at the same tempo on both of the recorders. The thing is, when we came back to that song to do bass tracks, the drums and scratch guitar weren't in time. The guitar was about a beat and a half off. I was just wondering if I need to use MTC or something similar to sync them together. If so, could someone please help me set it up? Also, while we are on the topic, how would I sync the 840 or disclab to my computer running Cubasis VST 3.0, and a 2448 digital audio card with TOSlink and phono S/PDIF? Any help would be greatly appreciated.

JM