[sdiy] Fwd: Re: Flangelicious noises - some queries about NCO jitter and resampling and similar

[René Schmitz]

Should've copied this to the list as well...

-------- Forwarded Message --------

Hi Tom and all,

On 23.01.2020 12:51, Tom Wiltshire wrote:

> Does anyone have any ideas about how I might reduce the problems in this 
> design? I see various issues:
> 
> 1) Resampling of the LFO output by the NCO reset
> 2) Frequency stepping caused by the NCO minimum frequency step
> 3) Jitter cycles caused by the NCO
> 
> Any ideas appreciated. I’d like to do a “version two”, but it’s only 
> worth it if I can squeeze a little better performance out of it.

One approach would be to somehow(*) raise the frequency of the NCO and 
divide it down afterwards. If the chip can not do that directly, its no 
longer a single chip solution. But if you could generate the frequency 
say 3 octaves up, then divide by 8, you reduce all effects.

Best,
  René

(*) yeah, right :)

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