sync'ing LFO from external source (MainStage)

[JeffCalder]

Looking for opinions here on where to focus my troubleshooting efforts ..

I have a CA2600 patch where I need the LFO modulating the amp env (Yes, it's Won't Get Fooled) .. and this is hosted in MainStage.

Sadly, we've transitioned from my laptop being the source of backing tracks and tempo/click, to the drummer being the source via a Roland SPD, which means I need to get clock from that via midi.

We haven't got that set up yet, but I've been making programming changes and noticed something odd.

CA2600 LFO locks nicely when the clock source is MainStage, but as soon as I set MainStage to get clock from an external source, the tempo gets initially set, but then drifts off .. like it only accepts the initial value or something. When looking at the tempo MainStage is receiving (from a Kurzweil via USB in this case), the tempo fluctuates but I'd expect that .. not sure there's a clock source that is absolute .. or is there?

Anyway, for this particular purpose I found that stopping/starting playback in MainStage resets the clock for the CA2600, and set a pedal up for this, but it's not practical as the stopping kills the audio briefly. I thought maybe with MainStage playing back the CA2600 may follow the clock better but it doesn't.

Anyone have any similar experiences or suggestions? For now I set up a tremolo effect on the organ channel which locks no problem, but it doesn't sound quite as good .. I'm sure it'll pass if it needs too ..

TIA