KVR Audio

Borogove · Post by **Borogove** » Mon Sep 12, 2011 11:17 pm

Swiss Frank wrote: Or in other words, by 768kHz, BumpUp double can play C7 faster than Naive Int16.

Hah, and there's very little audible aliasing, either.

oskari · Post by **oskari** » Wed Sep 21, 2011 11:05 pm

The new discoDSP Corona R2 has my version of this. I think I got some interesting variations out of it, check the super organ* patches for example.

george · Post by **george** » Thu Sep 22, 2011 7:54 am

oskari wrote:The new discoDSP Corona R2 has my version of this. I think I got some interesting variations out of it, check the super organ* patches for example.

They are located at Bank 002. Creation > Patches 040 to 049.

Richard_Synapse · Post by **Richard_Synapse** » Wed Dec 14, 2011 12:08 pm

A bit late to this thread, but looking at Adam's FFT picture, the supersaw is almost linear in terms of Hertz. E.g. check the difference in Hz between middle, and first/last partial. Not sure if that's a coincidence or hints at a specific algorithm (assuming of course his measurements are correct).

Has anyone tested whether the tuning changes at different base frequencies?

Richard

Aroused by JarJar · Post by **Aroused by JarJar** » Thu Dec 15, 2011 1:31 pm

mystran wrote:
Oden wrote: 1) The detune algo is almost ALWAYS linear. And I don't mean the detune knob(though that is non-linear too), but the detune itself. In JP8000 the detune values are far from linear as you just pointed. The relative values are: .893, .939, .980, 1.0, 1.020, 1.064, 1.110. Instead of the commonly used -0.3, -0.2. -0.1, 0, 0.1, 0.2, 0.3.
When you make the detuned frequencies multiples of the base note frequency, you maintain constant pitch range in terms of cents (or semitones). With linear detuning you get constant beat rates, but the higher notes will sound a lot less detuned. With exponential detuning (ie freq multiples) the beat rate varies, but the detuning in terms of pitch range (in terms of cents or semitones) stays constant whatever the frequency, so you can have half-semitone spread from the lowest bass frequencies all the way to Nyquist.

I've always wondered why everyone insists on linear detunes when the expo version sounds so much better to my ears unless one limits everything to a very small pitch range. Exponential is closer to how choirs, ensembles, even analog detuning tends to work. Things like chorus also gives you similar spreads.

As far as the exact ratios, it's not a huge deal what you use. A distribution where the "middle" frequencies are closer to each other and the "edge" frequencies spread more tends to maintain pitch perception better as there is more energy concentrated close to the nominal pitch. You might also want to sanity check that the beating ratios are sufficiently "random" that you don't get strong periodicity. I bet Roland's engineers just tried some arbitrary numbers and tweaked until it sounded/behaved nicely. Significantly different distributions DO give significantly different character, but ignoring the "badly behaving" coefficient set, slight variation isn't very noticeable most of the time.

Nice post. Unless you insist on having your display in cents, and the corresponding predictability of knob effect, the cost of proportional detuning is low.

Richard_Synapse · Post by **Richard_Synapse** » Fri Dec 16, 2011 12:28 pm

Ok, I did some measurements on my own and can confirm Adam's findings. Furthermore, the detuning does not depend on the base frequency, as far as I can tell.

Richard

Mastrcode · Post by **Mastrcode** » Wed Mar 14, 2012 3:01 am

Look at This:

http://www.nada.kth.se/utbildning/grukt ... _10131.pdf

is all what You need to know...

Chris-S · Post by **Chris-S** » Thu Jan 09, 2014 4:53 pm

Hi,
just played around with Adams VSTi (JP6K). Good job. Very close to the original.

Also made some experiments with Audacity. Generated a saw and compared the naive saw with the highpass filtered. I don't noticed a big difference between both. Maybe my ears are too bad.

Chris

Chris-S · Post by **Chris-S** » Fri Jan 10, 2014 3:17 pm

Also made some experiments with Audacity. Generated a saw and compared the naive saw with the highpass filtered. I don't noticed a big difference between both. Maybe my ears are too bad.

The error was I used low pitched saw waves. With a 1000 hz wave the difference between the raw and the HP-filtered wave is clearly audible.

But there's still a big diff between the filtered saw and a non-aliasing saw with 20 harmonics.

Swiss Frank · Post by **Swiss Frank** » Sat Jan 11, 2014 5:28 pm

I've just released my interpretation of Szabo's paper, implemented as a package for Moselle.

And while I haven't heard Szabo's JP6k or a real JP-8000, it sounds pretty trancy.

-------------------

Now let me back up and explain that.

In the last year I've developed and released Moselle IDE, a standalone music synthesizer for Windows, that can be programmed in a special "modular synthesizer programming language" called Moselle. Hook up a MIDI keyboard to your computer, and MoselleIDE will play music out your speakers. For more basic details, please follow the below link.

http://moselle.invisionzone.com/index.p ... a-release/

Today's release of Moselle includes support for "packages" which are similar to libraries in other languages. In effect, a package can be used like the built-in modules (Oscillator, Envelope, etc.) but a package isn't built in. Instead it itself is written in Moselle, and can contain arbitrary numbers of modules (and other packages).

This first release with package support has eight packages. One is the SzaboSawOsc. Others include oscillators similar to Casio CZ keyboards; Leslie simulator; reverb and reverse reverb; soft limiters; and alternative tunings.

ChewingAluminumFoil · Post by **ChewingAluminumFoil** » Mon Jan 13, 2014 9:42 pm

I'd like to hear a sound sample of this.

CAF

Swiss Frank · Post by **Swiss Frank** » Tue Jan 14, 2014 4:35 am

Of Moselle's Szabosaw? I've been meaning to make a youtube vid demo, and could feature this. It wouldn't be today or tomorrow though I think...

Swiss Frank · Post by **Swiss Frank** » Wed Jun 14, 2017 5:51 am

Hey guys, I thought I mentioned that based on our discussions here several years ago, I made a super-super-super-supersaw oscillator for my software synthesizer Moselle.

Here's a video with 700 (or more? MANY more???? Watch the vid!) sawtooths, plus various super-square, super-triangle etc.

The software's available for free download from http://moselle-synth.com . Still alpha, but almost beta quality. I'd love to hear some input on it.

xoxos · Post by **xoxos** » Thu Jun 15, 2017 11:21 pm

! now random, rate controllable modulation of pitch and amplitude for each osc

Swiss Frank · Post by **Swiss Frank** » Fri Jun 16, 2017 7:48 am

Xoxos, don't forget panning too.

Moselle has a module called Adder, which specializes in additive synthesis. It ONLY has pitch and amplitude for each osc, but is high performance.

There's also a module called FMAlgo, which is like Adder, but additionally has a modulation input for each osc. Each waveform has specific outputs for pre-gain (for DX-7-style feedback), non-amplitude-scaled (for modulation) and audio purposes, and phase inputs.

But there's no fixed number of oscillators, so if you just want to vary everything simultaneously, just make a big handful of normal oscillators. I've got a demo patch that uses 10 regular oscillators... then uses an FMAlgo not as an oscillator but as a CPU-efficient battery of 30 LFOs, setting panning, volume, and detune for the regular oscillators.

Back to the swarm: you can specify an overall "shape" for the waveforms, controlling frequency and amplitude. For instance you might want the detuned ones to get quieter as they get farther from the center, and spaced farther apart. You can set those EXACTLY how you want, osc by osc if you want. Now: once the Swarm is playing, you can't vary that shape, but you can adjust the overall shape to be wider and narrower, taller and shorter.

Roland Supersaw - any idea how the original was done?