[sdiy] Saw vs Triangle Sync

[Cynthia Webster]

David G. Dixon wrote:
>> I'm sure both sync types are useful, but sawtooth hard sync
>> represents what I believe most synthesists think of as the hard sync
>> sound. "Lots of harmonics" is usually the whole point! Modulate the
>> pitch of the synced VCO with an EG and you get the classic ripping sound.
>>
>> I like soft sync a lot, too, but that is yet again a different sound.
>>
>> "Different syncs for different thinks."
>>     
>
>
> AH-HA!!  So, "soft sync" is Tricore sync, and "hard sync" is Sawcore sync.
>   

Oh No!

Hard and soft sync has more to do with the ~depth~ of the modulation of 
the sync.

A Sawtooth core vco resets once per cycle, but a good triangle core 
resets ~twice~ per cycle...
(that is once at the top center of the waveform, and again at the bottom 
center per cycle)

Cyn
> It is all crystal clear now!  (This has been confusing me for a year!)
>
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>   

Very interesting below about types of sync preserving the original 
harmonic content

Cynthia

http://www.cyndustries.com/


Also good is the stronger the signal below is the sync that wins!

Soft sync is like hard sync with one key difference. Hard sync restarts 
the wave whenever there is a sync signal, period. Soft sync, however, 
requires the slave osc to be within a certain (variable) range of 
resetting, anyway. The result is that soft sync tends to act only when 
the slave's frequency is harmonically related to the master osc's 
frequency. Somebody posted pictures once, wish I could point you to them.

I would guess that soft sync can work with either saw or tri core.


David G. Dixon wrote:
Now that I've got some Sawcore VCOs to compare with my old Tricore VCOs,
I've noticed that the biggest difference is in how the two behave under 
hard
sync'ing.

In a Sawcore VCO, the saw integrator is reset to ground at odd times.  This
leads to piecewise discontinuities in the derived triangle and sine waves.
This imposes a "saw-like" sound on these waves, with lots of harmonics.

In a Tricore VCO, the triangle direction changes at odd times.  This leads
to triangle and sine waves with no discontinuities, and hence, few added
harmonics.  In other words, the triangle and sine waves retain their 
"siney"
flavour even when sync'ed.

I have to confess that I much prefer the sync behaviour of the Tricore VCO.

Just something to consider when trying to decide which kind of VCO to
use/build/buy.  Having both kinds is probably the best option.


I would think the ability to choose between "Reset waveform" sync and 
"Change direction" sync would only be available with a Tri core. Yes? 
No? Tim (not sure whether I should be undecided... or not) Servo

Can you say "Zeroscillator...?" :)
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