Technological Idea: DCO that emulates a VCO

In my previous post you can hear what the digital oscillators sound like when ran through analogue filters. There's still surprising amount of digital preciseness to the sounds you get. If you somehow get rid of that preciseness, you should probably end up with much more analogue sound.

This preciseness doesn't necessarily come with digital oscillators alone. Some DCOs are very capable of it too. One great example of this is Dave Smith Instrument's Prophet '08 analogue synth. Its DCOs are super precise and cutting. They're probably even more precise sounding than most VAs, which might be the results of really high speed control over the DCO cycle times (much higher than 44.1 kHz). To be honest, I've no idea in what frequency the Prophet '08's DCOs are controlled. All I know is that they sound super precise and they're a perfect example of a precise DCO sound. This got me thinking one technological idea I had a while ago.

What if DCO could emulate very convincingly the unstable VCO sound?

The basic concept is fairly simple:
Trigger the DCO using an analogue modeled simulation of VCO's cycle triggering circuitry. For example take Korg Legacy Collection MS-20 software synthesizer and throw away everything else except the algorithm which triggers the oscillator cycles. Now put this very same algorithm inside the chip/cpu which triggers the DCO cycles. What you should end up with is a stable DCO which still sounds like your unstable vintage VCO.

Here's hoping for that one of the big three synth manufacturers would release a new analogue synth with such oscillators... Not gonna happen :(

Technique test: Sylenth1 used as oscillators for a modular synth

A short while ago I tried out what it would sound like if I used LennarDigital Sylenth1 synth plugin as the oscillators for my Eurorack modular synthesizer. I've had this idea for quite some time already, but it was only recently when I actually tried it out. I send the unfiltered oscillator sound to various Eurorack format filters and triggered the envelopes using MIDI and then recorded the results back into my DAW. Here are the results:

Alternative content

The filters can be heard in the following order:
0:00 - 0:21 = A-124 (Wasp filter)
0:21 - 0:45 = SY02 (MS-20 filter)
0:45 - 1:12 = Boogie Filter in 24dB mode
1:12 - 1:42 = Boogie FIlter in 6dB mode
1:42 - 2:15 = A-106-6 in 4L mode (XPander Filter)
2:15 - 2:44 = A-103 (303 style filter)

Note that I didn't try to aim for any cool sounds with this experiment, but tried to draw out the different characters of the filters. I also mixed the bass very loud so you'd hear their character and still hear the timing of the sounds (hence the drums in the background).

What's surprising is that there's still quite a lot of that digital preciseness in these sounds. This was mentioned by several people who heard the results of this test. Yes, the analogue filter gives a very different flavor to the sound, but there's still some of that liveliness missing from these examples. This probably means that a lot of the analogue character many people love comes from the unstable oscillators. This is actually quite logical when you think of it. The filter does just what it says on the lid: filters out different frequencies. Sure it also adds distortion etc. but it doesn't modify the harmonic content the same way as for example pulse width modulation or unstable oscillator cycle time does, which is the oscillators territory.

It would be interesting to try this experiment the other way around; analogue oscillators filtered using digital filters. How analogue/lively would the sound be then?

But anyway, it's an interesting technique and I might start using it in some of my tracks in the future.

One final thing:

Naturally this technique works with any software and hardware VA-synth/sampler/ROMpler/FM-synth/etc. you can lay your hands on. Just take your favorite sampler/FM-synth and use it as the "oscillator" for your modular synth.