Maybe the problem is that the MIDI output of the SQ-64 is not optimized for the SD08 sound engine. Some synthesizers and drum machines may have unique MIDI implementations that require certain MIDI messages or settings to trigger certain sounds or parameters. In this case, it may be helpful to check the SD08 MIDI Implementation Diagram to see if there are any specific MIDI messages or settings that need to be used when starting up with the SQ-64. I found a useful link https://modwiggler.com/forum/viewtopic.php?t=239867&start=625 https://www.spydetectfree.com/ with a working and useful resource that might help you find a solution.