Blacet Filthy Filtre dither trimpot

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diophantine
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Blacet Filthy Filtre dither trimpot

Post by diophantine » Mon Apr 24, 2017 7:29 pm

Has anyone with a Filthy Filtre messed around much with the dither trimpot in the VC Mode circuit? I know it goes from straight-up switching to some degree of dithering, and I'm wondering how useful people find it.

Does it provide actual crossfading between modes, or is it just the amount of overlap between adjacent modes?

I'm currently on the fence about picking up a Filthy at this point (though I may still get one down the road), but the VC Wave is perhaps the most interesting part to me. I'd be much more interested if the dither control provides cross-fading, and if that's the case I'd mod it with a pot on the front panel.

This seems to be one of the few trimpots settable to "user preference" that hasn't been discussed here as far as mods go.

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Tubeampguy
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Post by Tubeampguy » Mon Jul 03, 2017 9:26 pm

http://www.blacet.com/FilFmanualBasic.pdf

Page 5 explains calibration.
:tu::blacet: :tu:

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diophantine
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Post by diophantine » Tue Jul 04, 2017 8:19 am

I'm aware of the calibration details (that's how I found out about it), but it doesn't answer my questions.

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fracmonkey
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Post by fracmonkey » Tue Jul 04, 2017 8:50 am

"Does it provide actual crossfading between modes, or is it just the amount of overlap between adjacent modes?"

I think the answer is that crossfading and overlap are really the same thing.

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diophantine
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Post by diophantine » Tue Jul 04, 2017 6:49 pm

fracmonkey wrote:"Does it provide actual crossfading between modes, or is it just the amount of overlap between adjacent modes?"

I think the answer is that crossfading and overlap are really the same thing.
By "just [...] overlap" I mean that it is still just switching, just with an overlap, so during the entire overlap each signal is 50%.
Crossfading would go continuously from 100%/0% to 0%/100% during the overlap.

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fracmonkey
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Post by fracmonkey » Thu Jul 06, 2017 8:14 am

OK, lets say it is crossfading during the transition band.

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thee ghost ov n_phay
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Post by thee ghost ov n_phay » Thu Jul 06, 2017 3:55 pm

https://soundcloud.com/theda-electronic ... ering-demo
This is a middling pitch saw wave, fed thru the filthy filtre with middling cutoff and a little bit ov "q". The filter mode is swept by an LFO tri wave set to a (guess) middling speed. Hear the effect as the trimpot is slowly tweaked from fully CCW to fully CW and back again! Personally, I just set mine to about 1/3 of the way up and leave it there, works OK for me.

Filthy Filtre is a really good SVF, I think. Wd love it if JB made a nice 4-pole LPF to go w it.

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Cat-A-Tonic
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Post by Cat-A-Tonic » Thu Jul 06, 2017 6:39 pm

thee ghost ov n_phay wrote:Wd love it if JB made a nice 4-pole LPF to go w it.
or perhaps a revised 5-pole Final Filter with parts that are still available.

switchable to HighPass for bonus feature creep. :stardance:

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diophantine
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Post by diophantine » Thu Mar 22, 2018 9:43 pm

Somehow I totally missed this, thanks!! Sounds quite nice.

Just finished building a Filthy Filtre. Your dithered output sounds much smoother than mine (at any trimpot setting) - I get some noise/glitches at around 50% on the pot. Need to try it with a CV this weekend and potentially do some debugging with the schematics in front of me. Otherwise it seems to be working fine!

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Post by e-grad » Fri Mar 23, 2018 10:07 am

Cat-A-Tonic wrote:or perhaps a revised 5-pole Final Filter with parts that are still available.
My favorite VCF.

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