Advanced Sync for the VC Master Clock

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC

Hey Fonik, it sure would be cool to have these two circuits combined on one PCB. Although I had a hard time doing so, I held back on buying any of your original PCBs for this very reason, no sync. But, with sync added on, this would be a perfect little utility board.

What do you think, sound like a good idea? Any chance of that happening?

fonik · Posted: Tue Jun 28, 2011 11:03 pm Post subject:

diablojoy could do it!?

diablojoy · Posted: Wed Jun 29, 2011 2:54 pm Post subject:

ericcoleridge · Joined: Jan 16, 2007 Posts: 889 Location: NYC

I don't mind etching if u guys dont mind posting your layouts.

whomper · Posted: Fri Nov 18, 2011 4:06 am Post subject:

I have finally gotten to re-connect my dual VC clock with the sync board today and have run into two issues:

1. Although components are identical, one clock runs much faster than the other one.
2. When connecting an LFO to the Sync input, the VC clock's PW goes to almost full open and disregards the PW POT position.

Not sure whether #1 is related to the sync board, but probably #2 does.

Any hints?

diablojoy · Posted: Sat Nov 19, 2011 12:38 am Post subject:

whomper · Posted: Sat Nov 19, 2011 1:50 am Post subject:

Hi diablojoy

I am getting %98 PW on when the PW is at its lowest position and 100% on when i move the pot a little.
Have beads on the VC clocks boards.
Using 15v.
Have the board with DG413, but left everything in tact, even the two 22K resistors that where on board, though the schematics indicates I should remove them. (tested the board without them, no change).

diablojoy · Posted: Sat Nov 19, 2011 4:37 pm Post subject:

DG413 ok you can leave in the 22k if you dont wire off to the switching jacks

whomper · Posted: Mon Nov 21, 2011 1:15 pm Post subject:

Did some more testing:

1. The >95% is attributed to the inserted clock signal, which was a wide pulse from an LFO. I thought that the sync board would trim it down to a pulse and use it only to trigger, but for some reason (maybe by design) it uses the incoming clock pulse duration for the outgoing clock duration. The PW knob has some impact, but clearly there is a relationship between incoming clock pulse width and outgoing clock pulse width.
2. If the internal clock speed is faster than the incoming one, there will be no syncing and the resulting clock will be as fast as the internal.
3. Have left the master/slave panel switch off and in an open state, i.e. the two pins are not shorted together. Does it make a difference?

diablojoy · Posted: Mon Nov 21, 2011 4:56 pm Post subject:

diablojoy · Posted: Sun Dec 04, 2011 4:30 pm Post subject:

whomper how have you fared with this any further progress ?
did you manage to get it running ?

whomper · Posted: Wed Dec 07, 2011 12:42 pm Post subject:

did not had a chance to look at it due to tons of work...

will re-wire all links today evening and report back.

Thanks

NuttyMonk · Joined: Jun 30, 2020 Posts: 63 Location: UK

Hi all,

i was trying to get a sync setup working on the Fonitronik VC Clock.

When the Saw wave gets down to 0V the comparator IC1B triggers the discharge of C2 so i thought that would be an easy way to mod the schematic. Just by shorting Pin 5 on IC1B to ground it shorts the capacitor C2 and restarts the cycle.

Works well in simulation. Am now about to try it on the breadboard as an On/Off switch. I am also considering how to short Pin 5 on IC1B to ground using an input signal of 0-5V square wave converted to a trigger. I'm not good with transistors so am considering just using a single SPST IC switch instead which i do understand.

Maybe that will help anyone else trying this.

Cheers

NM