RADIAS Problem with Sync Mode on Osc2

CFC · Post by **CFC** » Mon May 10, 2010 8:02 pm

I may be just misled but I have a problem with the sync mode on osc2.
When I switch sync on and turn down the mixer for Osc1 I do get synced sounds by detuning osc2. But regardless what waveform I choose for osc1 and how much I turn the control 1 knob on oscillator1 the sound coming out from the amp section stays the same.
Shouldn't Oscillator 1 add a (tuneable) overtone structure over Oscillator 2?
I am pretty confused because when I choose Ring Mod everything (including input on Osc1 knob1) works propperly.
Am I doing something wrong or is my radias going nuts?
I just started working on it so I hope its the first choice ><

And sorry for bad english. It's not my native language but @ the german KORG site nobody seemed able to help me out.

Greetz

X-Trade · Post by **X-Trade** » Mon May 10, 2010 8:18 pm

The Radias implements 'Hard Sync', not 'Soft Sync'. What that means is the waveform of OSC2 is re-triggered every time OSC1 crosses the zero-crossing point in the positive direction.

Soft sync is more variable but I've never known it myself.

Changing the controls for OSC1 only change the timbral structure of OSC1 (changing the waveform or whatever in osc1's waveform, which means it still has the same base frequency and so the sync will be the same.

I actually think the RADIAS implementation is even simpler than that because it doesn't seem to work with Audio In mode. I think the sync signal is actually driven by the phase ramp rather than the waveform itself.

I did notice you can get some funky feedback effects by using ringmod or ringsync and crossmod (osc1 phase modulated by osc2) at the same time.

Anyway, changing the timbral structure of the sync sound is achievable by changing the detune of oscillator 2.

CFC · Post by **CFC** » Mon May 10, 2010 8:34 pm

First of all thx for the reply.

So just to get things straight.
The sync for oscillator 2 is the same for every waveform I choose for osc1? So why does the manual trick my by saying I can synchronize Oscillator 1 to Oscillator 2 when it is totally immaterial which waveform I choose for osc1 because the outcome is always the same? Shouldn't be there a different trigger time for the zero crossing when osc1 is a square as when it's a sine?
Am I not able to tune osc1 to trigger the zero crossing line more often, or less often?

Holy moly...confusion strikes me pretty hard at this one ><

X-Trade · Post by **X-Trade** » Mon May 10, 2010 9:30 pm

Well, consider a sine wave and a square wave at the same frequency have the same phase start (zero degrees) initial crossing position. Because they are the same frequency they are the same wavelength. A shorter wavelength would be a faster repeating cycle and so a higher pitch. A slower repeating waveform would be a slower cycle and so a lower pitch.

So you vary the amount of times it retriggers by changing the relative pitch of the two oscillators. They have designed it so that you vary OSC2 pitch because changing the pitch of OSC1 (the sync source) would change the perceived pitch.

consider pitch is related to wavelength, and with sync you are effectively cutting off the waveform of OSC2 to make it fit exactly with the wavelength of OSC1.

CFC · Post by **CFC** » Mon May 10, 2010 9:41 pm

Yes. I just got my bright moment.
I was too fixed on the image of the waveform and haven't thought about the pitch aspect of the sync.
It's a lot clearer now. ^^
Thx man!