Just throwing it out there: I don't have proper equipment to align the 688 tape heads or check the tape travel (this includes the Teac MXT-111 tape with the 3kHz tone and MXT-1161 tape with 315Hz and 6.3kHz for azimuth and head touch). There's also head adjustment jigs (part #s: 5736006600 and 5736006700) which i can't seem to source on the used market. That said, and trying to get as close as possible, will recording a test tone on cassette side A on all 8 tracks (bussed from a single, known-to-be-good channel) and then FLIPPING the cassette to side B for playback tell me how closely aligned the tape path and heads are aligned from track to track? I would think without "bleed" from track to track or loss of dB per track I'd be pretty close to decent alignment. Seems as if a recorded tone on track 1 (side A) played back correctly (with the same metered level as when originally recorded) on the B side (which will effectively be track 8 now that it's flipped) would indicate a reasonable alignment within the 688. Testing the signal from a frequency generator as it's recorded (monitored post tape) and played back through an oscilloscope should tell me provide useful info. Until I can find the rest of the test equipment, I can't think of another way to try out the repro function. Thanks, as always for any insight you may have.