New module, fractal gain sequencer

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CLee
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New module, fractal gain sequencer

Post by CLee » Sun Sep 15, 2013 4:46 pm

UPDATE 8.3.15
Here is a new video demo

[video][/video]

the panel shown below is out of date and lacks newer controls

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Here is some info on a new module I'm working on. I'm getting very close to a functioning circuit. I call it a Fractal Gain Sequencer (or maybe Arbitrary Wave Multiplier). It takes an input signal and steps through one of 8 pots, the higher the voltage the higher numbered the pot. The pots control the gain of a balanced modulator. 12:00 is zero gain with positive gain CW and inverting gain CCW.

With input set to INA/CV the pots will modify the waveform input to CV. Input B can be +5, set like that the output will be like a sequencer. With input B set to EXT the pots will control the gain of a second waveform, much like a ring modulator.

The Fractal control will cause the 8 pots to modify a smaller range of voltages, and the pattern of the pots will be repeated.

Here is a messy mockup of a front panel. Gate outs will go high with the corresponding pot and could be left off if you use the module as a waveshaper.

Image

Here is a video of an early test,
[video][/video]

The signal path (VCA and Pots) is fully analog but is controlled by a PIC chip.

I haven't tested the circuit much to see how the DC accuracy is, and still have a ways to go. But I think it's cool...
Last edited by CLee on Thu Sep 03, 2015 9:05 am, edited 3 times in total.

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diablojoy
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Post by diablojoy » Sun Sep 15, 2013 5:01 pm

ooh that is really cool
will be watching the development of this one
It probably wont happen today but if it does it definitely wont go smoothly.

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Post by falafelbiels » Sun Sep 15, 2013 6:30 pm

I find comfort in the fact that 4U is just eurorack sideways...
It sounds great and I want it!

Funny connectors we can work on.

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numan7
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Post by numan7 » Sun Sep 15, 2013 6:41 pm

:party: oh how cool!

i hope i get to build one or two of these...

cheers
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vurma
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Post by vurma » Mon Sep 16, 2013 1:21 am

This should be a very useful tool for messing up LFO signals. Id really like to hear the "Fractal" being CVd by a sequence.
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GrantB
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Post by GrantB » Mon Sep 16, 2013 1:38 am

Wow more stunning original work :hail:

feedback patch?

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andrewF
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Post by andrewF » Mon Sep 16, 2013 1:40 am

Great idea, love what it can do to the waveforms!!

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Kent
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Post by Kent » Mon Sep 16, 2013 4:53 am

I want one in my Buchla. Now! :clap:

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vurma
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Post by vurma » Mon Sep 16, 2013 4:58 am

GrantB wrote:Wow more stunning original work :hail:

feedback patch?
The feedback! Indeed, the feedback! Imagine what this could do as a spice to any generative patch.
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Post by oberkorn » Mon Sep 16, 2013 7:06 am

very original idea. so good we have seen a upsurge in interesting sequencer ideas (fonik et al), this raises the bar. please sign me up for a PCB :)
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jgb
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Post by jgb » Mon Sep 16, 2013 7:44 am

Great idea!

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Post by frozenkore » Mon Sep 16, 2013 7:56 am

Sounds great and it's a really interesting idea!
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mush
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Post by mush » Mon Sep 16, 2013 11:45 am

I'd love a pcb for this one. I could see the eight "sequence" pots replaced by sliders for a euroversion though.

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Post by FetidEye » Mon Sep 16, 2013 11:57 am

wow!
i would also like a pcb!!
looks super useful

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CLee
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Post by CLee » Mon Sep 16, 2013 6:23 pm

Thanks guys. The circuit is working, now I just need to get it working well. I hope to get some more samples up soon.

Craig

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lvoemachine
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Post by lvoemachine » Mon Sep 16, 2013 6:53 pm

yeah, I'll definitely want a pcb of this as well. Looks super interesting.

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raisinbag
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Post by raisinbag » Mon Sep 16, 2013 9:33 pm

wow that was a super cool demo, the kids liked watching the fractal shapes on the Oscope. Hopefully I will have some bread when you release the PCB.

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arrmcbain
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Post by arrmcbain » Tue Sep 17, 2013 7:04 am

That looks amazing!

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Girts23
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Post by Girts23 » Tue Sep 17, 2013 1:53 pm

Great idea! I'd be interested in PCB, as well.

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theabsent
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Post by theabsent » Tue Sep 17, 2013 2:40 pm

I want one pcb!
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logicgate
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Post by logicgate » Tue Sep 17, 2013 3:40 pm

in for a pcb :party:

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spotta
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Post by spotta » Tue Sep 17, 2013 4:17 pm

Now THAT's what I'm talking about!
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bananeurysm
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Post by bananeurysm » Tue Sep 17, 2013 5:33 pm

I'd build one!

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terrafractyl
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Post by terrafractyl » Tue Sep 17, 2013 5:56 pm

I'm in for one (of course!)
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Post by wavehead » Tue Sep 17, 2013 7:23 pm

i want one. seems pointless in even saying it... who isn't going to want one of these?

interested to see what a smaller, non-seq panel would look like.
in buchla it should be a really nice fit.

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