I spent the afternoon trying to figure out what was up between Reaper and my Pyramid.
TL;DR: Pyramid clock is locally rock-solid but globally gets slowly out of sync compared to Reaper.
I have Reaper setup to listen for SPP from the Pyramid, with both set the same BPM. I then record tracks one by one. The recorded tracks stay perfectly in sync with each other but gradually drift out of sync with Reaper’s beat markers. For example, if I record 30 bars of 4-on-the-floor kicks at 120 BPM (240 beats), Reaper’s final beat marker is at 60.000 seconds, but the last beat recorded has its onset at 59.986 seconds.
I did the math and, basically, if I set the Pyramid to 120BPM, and Reaper to 120.028 BPM, Reaper’s beat markers and Pyramid’s triggered beats stay perfectly in sync over a 60 second recording period. So that’s a solution for 120 BPM (unless you’re recording for >10 minutes, I guess). Unfortunately the BPM offset seems to be different depending on the Pyramid BPM - but at least it seems to be consistent and repeatable.
I’m going to dig a little deeper - hoping I can come up with a consistent solution that works across different BPMs.