[sdiy] little phatty question

[Luís Marka]

Isn't this the same effect one would get using Pulse output of a synth 
as the sync source, and changing the pulse width? I tried this with one 
of my oscs that syncs thru a LM311, and it sounds like the sync gets 
"stronger" and "weaker" accordingly to the pulse width.

Luis Marka

Michael Bacich escreveu:
>
> On Mar 29, 2006, at 2:42 AM, ニコラス・ケント wrote:
>
>>
>> I guess when it comes to doing something unusual with sync there's 
>> the Fenix where you can CV control sync "level" - - from no sync to 
>> hard sync with soft sync at the midpoint.
>>
>
> It's also possible to create a "phase modulated sync" circuit that 
> allows you to shift the actual sync point to anywhere in the phase of 
> the master sawtooth wave.  You can then use a control voltage to 
> dynamically modulate the phase point where the sync occurs.  
>
> Typically we use the master sawtooth's reset pulse as the master sync 
> signal, but that pulse always occurs at the same phase of the sawtooth 
> wave (usually at the peak of the wave).  Phase modulated sync lets you 
> make a reset pulse at any point in the master sawtooth wave, and lets 
> you dynamically move that point around with an LFO, an envelope, or 
> whatever control signal you choose.
>
> I have heard about such circuits, but I've never actually seen a 
> schematic or had a chance to hear one in action.  I am very curious as 
> to how it sounds.  I fear that it may not be a very dramatic effect, 
> especially compared to modulating the pitch of a synced VCO, but who 
> knows?  I'm guessing that these circuits use some kind of comparator 
> circuit that is similar to our typical saw-to-pulse converter, with 
> the pulse output then turned into a fast sync pulse.
>
> If anyone has a circuit for one of these, I'd love to see it.  I think 
> there may have been an Aries VCO module that had voltage controlled 
> Phase Modulated Sync.  This would have been a module that came out 
> near the end of the Aries company's history (when Paul Rivera was 
> running the company), and I don't think schematics ever got published.