TTSH Mod Sync Option
from Muffwiggler thanks to all supporter
Note: Green part (sync source) sits on one VCO (e.g. 1), red part (sync destination) sits on another VCO (e.g.3)!
As you can see the signal at the sync switch wires is pretty large (signal is a buffered, -5.6V to +14.4V pulse of 2us width with sync, or -9V DC at Q11-Gate when sync is off), and it controls a switch.
The problem is just if the large switching spikes couple from one side of the On/Off switch to the other, than it is still syncing somewhat, even if it should be off.
The large signals may stray to other circuits.
So maybe it is a good idea to run them shielded, especially when they are longer.
They are not "noise sensitive" in a way as a high impedance audio node. As long as the FET (Q11) stays off when sync is disengaged really nothing happens.
TESTED Version with SPST switch by nordcore:
When the switch is open the GATE side is relative sensitive, if you twist both cables the few pF between the cables are enough to give some "soft sync" effect.
That should be better, if you stay with the Odyssey version (which requires a SPDT switch, which I don't have ).
Source Side:
Plan:
in real world:
second pcb:
in real:
