What actually generates the wavetables?

[Timo]

Just wondering if anyone's still out there!

Been looking at the TI's wavetables under a microscope at differing octaves, and I'm left wondering how the individual waveforms are generated.

Some have artefacts that could be indicative of PCMs (they exhibit frequency- and/or bit-rate stepping at low octaves, as you would expect with a sample of a waveform:-

(Click waveforms for close-up)







(All waveforms above were recorded at 192kHz/24-bit to capture the artefacts in detail - the stepping/aliasing you see is NOT a limitation of the recording frequency of my soundcard [as I'm recording at rates that far exceed the input] but by the Virus wavetable waveforms themselves).

.... Other wavetables have artefects consistent with vector/amplitude-type generation (each single cycle is split into, lets say, 64 steps [keeping it simple, I imagine the actual figure is 1024 or greater], and lines are simply drawn between each step to make the overall waveform, like a dot-to-dot method) as you can see the straight, vector-like lines between each step:-





..... Other wavetable waveforms are incredibly complex yet entirely smooth even at very low octaves and could only appear to be mathematically generated algorithms.

Ultimately I'm curious, if Access enabled us to create our own single-cycle waveforms in a future Virus, what type of constraints they would give us in generating them and how detailed the waveforms could be. Whether it would be sample-based, or drawn in by hand (vector), and how they would transpose this across the keyboard without the need for multisampling in the case of PCMs or similar. A lot of the wavetables in the Virus have a tendency to sound very bell-like, I'm wondering what is required to minimise this.

God, I hope they put more energy into the Virus again sometime soon. There's been a rennaissance in keyboards the last few years, the world's moved forward, and Virus Control could do with an update.