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Lofi Mat frequency tuning


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#1 Zer0 Fly

Zer0 Fly

    Guruh Motha Fakka is Levitating and Knows Everything About Renoise Member

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Posted 28 October 2017 - 02:12

So its a mellow day's night again, and I'm sitting down to try to find a tuning formula for the Renoise 3.1.1 Lofi Mat device, so I could abuse it in one or another interesting way.

 

I found the Lofi Mat has broken tuning. Tuning its rates to match certain frequencies - it will display a different frequency than its decimator is actually working at. This could be circumvented, but even worse, the tuning seems also to be slightly dependent on the master sample rate, so tunings to match a frequency I found at 48khz are no longer valid at other rates.

 

Can this be fixed? I just made a nice instrument using the chorus decimator, having it tuned keytracked. Sounds very digital. Would have liked to use the lofimat though, much grittier sound and extra noise.



#2 ffx

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Posted 28 October 2017 - 10:49

Slightly off topic, but I would love to see a "real legacy dac mode" in the lofi device:  So that it was not aliasing as hell, but doing a proper downsampling, e.g. to 32k (Korg M1 / 01W) or 28k (Amiga).  Since now, the device adds lot of aliasing due only providing no interpolation, or linear interpolation. Those DACs from the 80s of course had much more sophisticated interpolation already. Currently target of the lofi device is the first DAC ever made in a laboratory, which is nice, too. But on low sample rate it is just aliasing purely. Compare with amiga playing a sample at 8000hz, or even the korg m1 vst. It still sounded smooth somehow, due some more advanced interpolation (maybe just spline interpolation)?


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