[SOLVED] Double Total Recall issue with clock syncing

[VerreyckenGerd]

Hi all,

I am building a double version of the Total Recall in a very big box.
I implemented a few extra switches for all the stereo routing options and all goes well till now except tapping off the CP1 and CP2 pulses from one board to the other for synced Left/Right delay time.
I cut the clock pulse traces on the second board and routed them to a DPDT switch for switching between clock sources board 1 / 2.
When I use the clock pulses from board 1 on the second board things sound like a distorted clock whine (only on the second board). On the scope I can't see any issues with the clock quality and moving cables/shielding etc. doesn't affect the issue. Also in normal mode the extra wiring to the switch doesn't bring any clock whining.

I am wondering what is wrong. The boards share there positive ground perfectly.

Also the whining's amplitude is modulated with the amplitude of the delayed audio so you hear nothing when not putting any audio and the whining fades out perfectly with the audio envelope.

All tips are welcome and thanks in advance!

SOLVED: It was a bad grounding of the cable shield after all.