Rationale for small offsets in output?

Algorithm development and general DSP issues

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Digital Larry
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Rationale for small offsets in output?

Post by Digital Larry »

For example, here are the last few instructions of the GA_DEMO_WAH.spn program:

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sof	1,0.02
wrax	dacl,1
sof	1,-0.04
wrax	dacr,0
DACL is shifted up by 0.02, then DACR is shifted down by -0.0008.

As far as I can tell, this puts a very small DC offset in the output. I can't understand why you would want to do this. I thought that perhaps it was to defeat limit cycles, but I don't think there is any recursive path in the given algorithm that would be affected by it.
frank
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Post by frank »

Good question, I wish Keith was still around to ask him. It may have to do with the first silicon of the FV-1, there was a minor birdie issue and small DC offsets can remove them. The DAC was fixed prior to release so the birdies went away but we forgot to remove the offset from the code. Won't hurt anything to leave it.
Frank Thomson
Experimental Noize
Digital Larry
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Post by Digital Larry »

Works for me Frank. Thanks!

I wish Keith were still around too, and I didn't even know him.

DL
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