Oscillator Warmth Circuit

Tim Kleinert

Hi,

Many folks have been complaining about the overall "cold" and "digital" sound of the G2 -and I've been one of the loudest. Laughing

The most well known remedy for this issue has always been Rob Hordijks "tilt filter" circuit. But as much as I appreciate this design, I always disliked the fact that it is a post-processing effect arbitrarily slapped onto the mix in the FX section, making it sound like a static sonic overlay to my ears. So I began wondering if there wouldn't be a method to warm up oscillators from within.

After hours of pondering and experimentation, I found a solution: a correctly tweaked PhasingFilter tuned to the oscillator, with it's spread and feedback parameters thus neatly acting as a tone control. It offers tweakability of the amount of processing applied, as well as the frequency bandwidth of this processing, thus giving complete control over boosting the lower and softening the higher "buzzy", "digital sounding" frequencies. With the appropriate setting, the oscillator thus just sounds warmer and seems to have more "pressure" behind it.

The PhasingFilter is rather costly DSP-wise, but imho the results are well worth the investment. After working with this technique for a few hours and building a simple "analogue-style" polysynth based on it, the basic G2 oscillators just sound like a joke to my ears.

This synth can be found here:
http://electro-music.com/forum/post-245901.html

Exclamation

The oscillator and the tone control filter have to be in tune with each other. Only use the MasterOsc module for manual pitch adjustment and pitch modulation. Do not change osc or filter frequency separately, and make sure their KBT is kept turned off.

Tweak Warmth amount and Warmth bandwidth to taste. Zero amount equals the original signal (obviously Laughing

), so toggling the level button lets you A/B the processing.

Exclamation

The osc shapes will look very warped on a scope. This is due to phase-shifting of partials caused by the PhasingFilter, and has no influence on the sound whatsoever, so it's nothing to worry about.

Have fun Smile

cheers,
tim

EDIT: The output seems rather low. I ran a DualOsc through it initially for testing, which has way more output, so I had to turn down the level knob of the PhasingFilter in order to prevent it from clipping. You can turn it back up to get more signal from a basic oscillator. Just make sure the filter doesn't go into clipping (like when using the DualOsc, as I did).

Osc-Warmth TK.pch2

Description:

Tone control for oscillators. Beef up the G2 sound!

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Filename:

Osc-Warmth TK.pch2

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1.54 KB

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dorremifasol · Posted: Wed Jun 10, 2009 10:05 am Post subject:

Does the band width have a well defined functionality? I'm not sure if it has to be tweaked as well.

It would be nice to have an "analog" oscillator module (or macro), with all the imperfections inherent to them, configurable. Clavia focused too much into delivering perfect oscillators. Maybe in the next modular (lol)?

Tim Kleinert · Posted: Wed Jun 10, 2009 10:53 am Post subject:

dorremifasol · Posted: Wed Jun 10, 2009 12:25 pm Post subject:

dorremifasol · Posted: Sat Jun 20, 2009 5:35 am Post subject:

I'm still trying to understand this trick.

So, if I'm not mistaken, what you do here is to emphasize the fundamental frequency of the oscillator?

Wouldn't do almost the same adding a frequency synchronized bandpass filter to the signal?

Please see the attached file, it's only a test over a work in progress patch.

Mopho2b.pch2

Description:

test

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Mopho2b.pch2

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2.29 KB

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Tim Kleinert · Posted: Sat Jun 20, 2009 6:32 am Post subject:

dasz · Posted: Thu Nov 05, 2009 1:36 pm Post subject:

tim,

I like this warming trick. hats off to you. salut

/Dasz