Volca FM and Oscillator Key Sync parameter

[OpAmp]

Hi,

In the parameter list, you can find back a parameter called: Oscillator Key Sync. It can be on or off.
Anyone an idea what it exactly does or whether there is an example program where you can hear it in action.

I played around with it in a few simple programs that I constructed, but I could not find one where I can tell there is a difference between Oscillator Key Sync on or off.

Thanks.

Bye.

[Spheric El]

I'm going to guess so I apologise.
It could sync the phase of osc cycle to note on.
Or in off it would would step in at any point in cycle.
Try some low freq modulators.A bit like LFO key sync?

[OpAmp]

Yes, I would think so as well.
Mmh, I did not think about low freq modulators...

My experiments show that oscillators of the different operators seem to be in sync whatever the setting is.
I was experimenting with one modulator and one carrier to end up with a square like wave. I was thinking that if key sync was off, that the square would distort each time I hit a note again.

[Spheric El]

(Keyboard tracking?)
Keep us posted on any discoveries

[rudeog]

I put together somewhat of a manual on programming the volca (available here: http://bit.ly/1URcSBx). Below is an excerpt for that parameter:
When the SYNC function is ON, all oscillator begin operation from the same phase angle (0
degrees). With SYNC OFF the phase angle at which an operator begins oscillation is carried over
smoothly from the preceding note. In the polyphonic mode, for example, maximum simultaneous output
is 3 notes. If a 4th key is pressed the first note makes a smooth transition to the 4th note.

[OpAmp]

Mmh, I tried out the low freq modulators, but I can not say I hear a difference, with Osc Key Sync on or off.
Same for the 3 note polyphony + adding a fourth one.

To be continued...

[rudeog]

Have you updated your firmware to latest? There were some things in the original firmware that were plainly not working.

[OpAmp]

Yep, I've done that as the first thing when I received the box It was funny, with my laptop it did not work at all, I had to do it with a cheap smart phone... But that is another story.

I believe this parameter corresponds to the Mode/Sync parameter of the Yamaha DX7. From that manual:

The other function, SYNC, enables you to set the operator so its "oscillator" begins at the start of the sine wave cycle each time you play a note. When Oscillator Key Sync is OFF, the sine wave continues so that subtle differences will occur even when you play the same note repeatedly. You may not be able to hear much difference in some voices.

So that is also what I expect from that function given the Korg name. I can not reproduce that with simple setups. My last trial was to set up 2 carriers, that are slightly detuned from each other, mono mode, and EG4 Level of 99. Each time I hit the same key, the sound is exactly the same, meaning both carriers start at the same phase giving a high signal (constructive interference), independent of the Osc Key Sync setting. While if an oscillator would not been reset by key sync, it would randomly start somewhere in the fading sequence (e.g. at less constructive or destructive interference).

My conclusion, unless proven elsewhere, is that this feature is not working...

Bye.

[rudeog]

It might be that the volca architecture doesn't support it (maybe it doesn't have free running oscillators), but they needed to put it in there as a placeholder to maintain compatibility with DX7 patches?

[OpAmp]

Mmh, could very well be what you say there. But it is then compatibility only in the parameter value and not in sound... It is a bit sloppy.

Now, I'm over it I'm not hunting after the one-on-one compatibility with the DX7. It's a nice box on itself.