DSP Robotics Support

Hey, I've a general question for the gurus out there - nothing to with the ESQ-1 project.

I was going through an ancient SM schematic called UniRetro by Christoph Bielen that was on the old Synthmaker website and I noticed that throughout most of the actual audio path he seemed to avoid using stream prims in favor of code modules, for things like vcas and mixers/adders. Prims were used more often for control voltages, etc. So in my most recent finishing up of old projects and re-dos, I did the same and it seems that the sound is much smoother and cleaner/fuller. Is this possible, or just my imagination? Maybe it's mostly the replacement of most of the oscillators with Vicanek's low-distortion BLITs? And/or his re-tuned SVF filter? Just seems like everything I've wrapped up lately sounds better. Also much lower CPU loads.

I apologize for my ignorance on these things - any thoughts?

Should be just the same Kevin mate.
Multiplies is exactly the same, whether code or prim,
as is plus

I kind of figured that, since both are just shuffling bits around - must be Martin's oscillators (or my imagination ;-} ). Any idea why Bielen would have gone to the trouble of doing that?

Here’s my opinion Kevin…

You changed the filter for Martin’s, and that’s probably the only effect that’ll be audible. Also, with the new and improved filters AND his oscillators I would expect the CPU to be a lot lower.

Plus, did you do a proper A/B comparison? If not, you might have a cognitive bias going on. Like if you expend a lot of energy or money on something, you anticipate an improvement.

Cheers

Spogg

As a long-time audiophile I'm all too aware of how easily one can hear what one wants to hear. But you don't think Martin's BLIT oscs are cleaner than the SM stock ones? I think he claimed a significant degree of reduction in distortion.

Did he do some other filters? - the only one I'm aware of is his 're-tuning' of the SVF.

I don't think there's a difference between the sound of the stock oscillators and Martin's. None that I can hear anyway, but others may disagree. The huge advantage is with CPU useage, which can be a reduction to as little as 10% of stock.

Martin has made many filters; I think of him as the Filter King. If you need something specific he will probably have it or even make it for you if you ask him. You'll find many examples on this forum but they'll 'll all be in FSM format of course.

Cheers

Spogg

I found where I got that impression - a note inside his sine osc that says "some harmonic distortion (<90%)" - I think he means that distortion is <10%. Is this lower than the stock sine osc?

I don't know!
I would ask Martin because I don't know how to measure thd, sorry!
Or maybe someone here has a tool to do this...

Cheers

Spogg

PluginDoctor can measure THD of a VST plugin ... as well as other useful tests [freq response, phase, harmonics, compression curves, etc].

k brown wrote:a note inside his sine osc that says "some harmonic distortion (<90%)"

Sorry that should read "harmonic distortion < -90 dB". That's a negligible amount of distortion and, since it is harmonic, it would not be perceived as disturbing (as opposed to aliasing). The stock sine generator has (negligible) distortion, too.