Programming Trick - Oscillator detune per voice

[pognoot]

Sharing a little programming trick on the OB-X8 I discovered.

As implemented in the OB-8, the Page 2 voice detune feature detunes both oscillators by design. It's a great feature! In addition to voice detune, however, detuning at the Osc level would further mimic the real-world tuning characteristics of the vintage units, especially the OB-X and Xa since their auto-tune routines were not as precise as the OB-8.  On certain OB-X8 patches, I've been missing those subtle Osc beat variations within each voice. 

Until now...

Here's the trick:  First bring up OB-Xa preset A1 as it's easiest to hear osc beating on a brass patch with no LFO modulation.   Then set the Osc 2 Detune knob to zero beats and play. The oscillators should be very tightly tuned across the keyboard.

Now go to Page 2 and scroll to Osc 2 Tri. Xmod, the set the value somewhere between 15-25.  Now start playing a single key and listen and it cycles through the 8 voices.  Notice the Osc beating is slightly different for each voice!   You can experiment with the Xmod value and Osc 2 Detune knob, going back and forth, changing the values until you get it exactly as you want.

Try it out!

[strytten]

Thank you for posting this. I just had a chance to try it out and it works just as you described. Very cool!

These are my favorite postings - how to use and enjoy the instrument, and how to learn more about programming possibilities.

[phil m]

That was useful to learn.  Excellent.  Thanks.

[337is]

Excellent tip and explanation, thank you!

[Teiko]

I played with this today and still not sure if I got the right result.

As far as I understand you are reffering to modulate the pitch of only OSC1.

By the XMOD in Page 2 you are modulating OSC1 with TRI OSC2.
With KNOB OSC 2 DETUNE you can adjust the intensity or frequency by which OSC1 Pitch is modulated.

But how does it differ to just use the vibrato LFO on the modulation panel and only select OSC1 as MOD destination ?
I compared both and they sound pretty same to me.

I didn't own an vintage Oberheim so maybe I am missing the background..

Furthermore in your example you mention to use the OB-Xa Preset which has an active Vintage Knob Setting.
Does this have some impact or does it make a change to the Vibrato LFO method ?

[shells]

Yep, thanks for highlighting this ‘insta-chorus’ tip. Although I found it kicked in from about 5 or even less. Scaled nicely.

With this, the osc detune and the voice detune - that’s a nice set of options.

Given this feature is an extra - I guess there’s probably a lot more that could be done in OS version 2.5 or 3.0. Shape mod dest would be nice. A sine wave osc shape too would be the cherry on top.

As this machine was a labour of love, I think they’ll keep going with it. Why not - unless they are deep in another project?

Just moving over to this instrument from the Trigon-6. My first impression is wow.