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Re: Syncing oscillators

Date1999-04-28 09:20
FromSteinersT1@aol.com
SubjectRe: Syncing oscillators
Hello,

syncing oscillators are done in synths for sound design purpose. When the 
master osc starts a new cycle, the slave is reset to start too. There is 
nothing exciting when they are at same Frequency, but with a high difference 
it introduces some metallic resonances. A common sound is when a frequency EG 
modulates the master osc. On some synths different modes of syncing where 
implemented, mostly soft- and hard sync.

Nice, I recently start to think about syncing in cSound too but with no 
conclusions so far....


Malte Steiner
---------------------------
Electronic Industrial Music
www.block4.com ____________

Date1999-04-29 07:31
FromAnders Andersson
SubjectRe: Syncing oscillators
> syncing oscillators are done in synths for sound design purpose. When the
> master osc starts a new cycle, the slave is reset to start too. There is
> nothing exciting when they are at same Frequency, but with a high
> difference it introduces some metallic resonances. A common sound is when
> a frequency EG modulates the master osc. On some synths different modes of
> syncing where implemented, mostly soft- and hard sync.
> 
> Nice, I recently start to think about syncing in cSound too but with no 
> conclusions so far....


This is very easy. Just replace your std oscillator (oscil) with a "phasor"
and a "table" (wrapping). This will do exact the same thing as the oscil,
but with the exception that you can multiply the output from the phasor
*before* it enters the table-stage, thus driving the table faster (or
slower) but still reset when phasor restarts.

*BUT*...

This could (*will*) cause serious aliasing, because of it's digital nature.

One solution to this might be to have an "oscillator envelope", that will
mute the oscillator a few samples at the start of a new cycle, and at the
end. This will distort the waveform, but atleast the aliasing is limited.

The correct solution to get the specific "sync" sound, is ofcourse to
analyze the output from an analogue sync-mod-oscillator and to synthesize
the precise spectrum, but this could be hard when you want a moving "inner
oscillator".


// Anders (MOS 6581 rewlz man! Syncmode in hardware.. =D)