Understand that when you are slaving a DAW to a tape machine, the DAW “listens” and synchronizes SMPTE timecode converted into to MTC or in some cases directly to SMPTE timecode, the SMPTE timecode being striped to a tape track. The 688 has an onboard MTC synchronizer for do this, like an onboard MTS-30. You don’t even need the JL Cooper unit if you have a MIDI interface for your computer and DAW. But that’s for slaving the DAW. You’re right…that doesn’t work the other way. If you want to slave the tape machine to the computer a synchronizer with the capability to do this, such as the MTS-1000 MIDIIzer, or something like a Timeline Micro Lynx, is needed. That’s because those synchronizers are able to receive the MTC from the DAW and convert that to capstan control voltage to vary the speed of the capstan motor in the tape machine, while reading SMPTE timecode from the tape machine and comparing that to the MTC from the DAW. And you have to have a rare interface cable to go between the synchronizer and the Accessory port on the tape machine, and that cable is specific to the equipment being used; the tape machine and the synchronizer. So your fantasy about trying to avoid getting the MIDIIzer or something like that because the are pricey, is just that…a fantasy…because you cannot slave the tape machine to the DAW without one. I’m not trying to be a black rain cloud, that’s just the reality. My advice? Save yourself the agony and figure out why your sync relationship with the 688 as master wasn’t reliable. Typically it is comparatively dirt-simple to slave the DAW, and like I said the 688 already had the capability onboard. All you need is a simple USB MIDI interface, which is often part and parcel to a USB audio interface, connect the MIDI out jack of the 688 to the MIDI in jack on your interface, set Logic to sync to incoming MTC, and then follow the instructions in the 688 manual for setting the machine up to reproduce the MTC for the DAW listen and sync to. Somebody tell me if I’m wrong because I never did it that way, and I’ll stay off my philosophical soap box here, because I still maintain slaving the tape machine preserves your digital audio and is the way to do it if you are syncing tape to DAW, but it was an expensive PITA back when I was doing it, and it’s only gotten harder as equipment availability dries up along with expert help you need to get it setup. I think for you, you really ought to take the easy path and slave the DAW. It should work. What do you have for a MIDI interface?