Hello, I am struggling with the positive and negative spice syncing.
After a short answer from @DaveVenom I managed to sync both (pos and neg) spices. But only at a special frequency below the spice frequency. I could create a stable, good-looking sine only, if the main spice frequency is half of the positive/negative spice frequency.
And it depends on the sample frequency of VCV Rack.
Currently I use the octave switch of the module to set of -1 for the main spice. And i switched on Spice sync. That works.
Now my question: is this behavior by design, or does it surely depend on technical reasons?
The overriding driving force behind the design is the behavior of the FSS hardware that I am emulating. I spent a lot of time poring over the limited available literature for the Osc 2 Recombination Engine, as well as deep dive videos about it. I am pretty sure I have replicated the functionality pretty well.
I suspect much of your concern stems from the label of SIN for the positive and negative spice. As noted in the Spice Factory documentation, it is really a rectified sine operating at 1/2 the frequency of the other spice waveforms. Early versions (prototypes?) of the Osc 2 use the text Sine on the faceplate, but the current hardware sports graphic labels, which I think lessens confusion.
I didn’t want to mess with drawing and fitting in graphic labels. But perhaps I should change the faceplate to use maybe R-SIN for rectified sine, or something of that ilk.
Setting the frequency of the positive and negative spice the same, and the slice one octave lower, and activating spice sync is indeed the only way to generate a normal sine wave with the spice. But that is a very narrow special case. I wouldn’t worry about that. There are many oscillators that can generate a sine (including the slice sine output).
The main purpose of the positive and negative spices, combined with the slice switching, is to generate novel new wave shapes, not revisit traditional forms. Very often (maybe typically?) the positive and negative spices will have different frequencies. Ain’t no way that is ever going to generate a clean sine wave.
I can’t read the mind of Finlay from FSS, but I think the phase and sync relationships in the Osc 2 / Spice Factory make a lot of sense. With the spice sync enabled (and all phases set to 0 in Spice Factory), both the positive and negative spice waveforms start at 0V when they are first switched on by the slice. If the spice frequencies are an integral multiple of the slice frequency, then they will also end at 0V when they are switched off. This enables the module to be less “clicky”. Of course the ability to use sine or triangle as the switching slice waveform enables all spliced results to be smooth, regardless of phase and sync relationships. But with the square slicing waveform used by the hardware (and by default with Spice Factory), the sync and phase relationship design is very important.
i do not want to create a sin as the main result, I use a sine wave as base for further sound creation.
usually I start with sine waves and walk on. this is the reason I bought spice factory, because there are many possibilities without filter. currently I am on the path to create metallic bell sounds. with FM, additive synthesis or karpus-strong I got some good results.
