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EG and LFO Modulation Artefacts

Posted: Thu Feb 08, 2024 3:24 am
by SeedyLee
Hi everyone,

I’m coming from a Kronos and have recently procured both a Kross 2 and a Krome Ex (gotta catch them all!), both of which have the EDS synth engine as opposed to the Kronos’ HD-1, AL-1 etc.

Last night I was creating a simple patch with a single-cycle sawtooth wave, and an EG and LFO modulating cutoff on a 2-pole filter.

What I’m finding though is that the modulations, both the EG with a slow release which closes the filter, and the LFO, is creating artefacts. Not sure if these are aliasing artefacts, or quantisation artefacts caused by the resolution of the EGs and LFOs, but they’re quite noticeable. Particularly at higher frequencies.

Any ideas if these are avoidable or if anything can be done to minimise their effects?

Thanks!

Posted: Sun Feb 18, 2024 8:21 am
by SeedyLee
For those who may be interested, there are two things I’ve found useful for alleviating the problem. One is to use two filters in series, with a HPF to filter out some of the low frequency artefacts. The other is to use a key tracker to reduce the amount of LFO modulation at higher frequencies.

Posted: Fri Mar 01, 2024 12:23 pm
by Dan Stesco
Hi SeedyLee is true, the Krome/Kross subrate is different comparison with Kronos. For example if use the LFO sine wave and hi speed, the LFO waveform will be slightly modified. Become random.

Posted: Thu Mar 21, 2024 6:14 am
by SeedyLee
Thanks, Dan, that's interesting. Whilst I'm not using any high-frequency LFOs (is that even a meaningful thing to say?), that is indeed what it sounds like. I will need to compare to the Kronos with the same patch settings on HD1.

Out of interest, do you have a reference about the difference in control rates between EDS-X and HD1?

Posted: Wed Apr 03, 2024 1:58 pm
by Dan Stesco
Hi SeedyLee,
I don't have all the references related to the differences between the engines either. When we were working on sounds and found something suspicious, we would ask the engineers.
Also the PCM are different even name the same, could be compressed, or optimised at number of notes so that could be reflected on filter behaviour.

Posted: Thu Apr 04, 2024 4:12 am
by SeedyLee
Ah, that's interesting about the difference in PCM - I really wish companies weren't so opaque about such things. Though now that you mention it, it somewhat confirms my suspicions that the issue may be with the samples being stretch over a greater range, or more compression - that does sound like what I'm perhaps hearing.