[Fpga-synth] Oscillator Sync to gate

[Scott Gravenhorst]

Hmm, good question as usual.

"The making of synthesizers in FPGAs." wrote:
>Here's another little philosophical question:
>
>If you've got a simple synth with a standard signal flow:
>
>pitch cv -> osc -> vca -> out
>                     ^
>                     |
>gate ----> adsr ----+
>
>is there any advantage to syncing the osc to the gate such that you get 
>the same initial phase on every strike of the note? It seems the typical 
>configuration of a modular synth will not try to do this, choosing 
>instead to let the oscillator run free. Perhaps commercial (digital) 
>synths do this?

Dunno about commercial, but my GateMan synths do not synchronize the NCOs to anything
at all (well, except for the mono version which can use one NCO to synch another for
timbre purposes).  My 55 year old ears don't hear anything nasty, but then maybe they
just don't ever hear anything nasty...

>Advantages of sync would be to get identical waveforms every time you 
>hit that note. Disadvantage would be that you get identical waveforms 
>every time >grin<. I suppose it depends on how much variation you're 
>looking for.
>
>What's your preference?

Whatever is simple and makes no sonic difference.

I would think that synching a sinewave NCO to the GATE would prevent a transient
during the attack (assuming a stark vertical attack shape).  I would assume that the
transient would probably annoy Mr. Nyquist, however, I'm not sure that I can hear this
or specifically perceive it due to it's short duration.

Your milage may vary...

-- ScottG
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-- Scott Gravenhorst
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