Cwejman RES-4 individual outputs mod

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macumbista
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Cwejman RES-4 individual outputs mod

Post by macumbista » Mon Sep 21, 2015 6:51 am

A client wanted individual outputs for each filter in his RES4, so I brought those and the power bus to the breakout cable. He'll make four buffered outputs from there on. It's a very worthwhile mod and easy to do once you've found the right pins of the ICs, so I thought I would share it here.

EDIT: original second photo showed wrong IC pins tapped. New image shows correct modification.

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Buffers will be standard op-amp config, like this CGS DC mixer without the attenuators since the RES4 already has them:

Image
Last edited by macumbista on Tue Apr 05, 2016 5:38 am, edited 2 times in total.
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flo
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Post by flo » Mon Sep 21, 2015 7:40 am

That's pure madness :eek: :woah: I'd never dare to do that

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Post by Dogma » Mon Sep 21, 2015 8:06 am

That was my initial thought too but worth it yes?

OP: Would you be up for the famed VM-1 mods?
look up!

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Post by macumbista » Mon Sep 21, 2015 8:19 am

Dogma wrote:That was my initial thought too but worth it yes?

OP: Would you be up for the famed VM-1 mods?
I'm usually up for anything! Do you have a link to the mod docs?
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Post by BugBrand » Mon Sep 21, 2015 8:21 am

Why wouldn't you just use standard non-inverting opamp buffers as the outputs? (simply use a single TL074) Or were you wanting to have it so you could easily switch phase/inverted?

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Post by macumbista » Mon Sep 21, 2015 8:23 am

BugBrand wrote:Why wouldn't you just use standard non-inverting opamp buffers as the outputs? (simply use a single TL074) Or were you wanting to have it so you could easily switch phase/inverted?
I suppose that would be simpler, yes. CGS diagram was just handy to send.
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Post by listentoaheartbeat » Mon Sep 21, 2015 9:30 am

flo wrote:That's pure madness :eek: :woah: I'd never dare to do that
We neither, which is why I asked Derek to tap the SMD circuit.. :)

Will post audio as soon as it's up and running!

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Post by echoplex » Mon Sep 21, 2015 11:22 am

listentoaheartbeat wrote:
flo wrote:That's pure madness :eek: :woah: I'd never dare to do that
We neither, which is why I asked Derek to tap the SMD circuit.. :)

Will post audio as soon as it's up and running!
also show pics of the breakout modul please once you got your modified res-4 back :tu:

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Post by M6live » Mon Sep 21, 2015 11:47 am

Redacted.
Last edited by M6live on Mon Nov 27, 2017 12:12 am, edited 1 time in total.

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Post by Summa » Mon Sep 21, 2015 1:16 pm

Oh, I want that! macumbista you're PM'ed!

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Post by Spunny » Mon Sep 21, 2015 1:39 pm

:woah:

a VM-1 with an envelope breakout would be fkn swell ..

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Post by echoplex » Mon Sep 21, 2015 2:05 pm

Spunny wrote::woah:

a VM-1 with an envelope breakout would be fkn swell ..
okay, now I want my BLD to have a CV input for the cutoff :yay:

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Post by listentoaheartbeat » Mon Sep 21, 2015 3:25 pm

echoplex wrote:
listentoaheartbeat wrote:
flo wrote:That's pure madness :eek: :woah: I'd never dare to do that
We neither, which is why I asked Derek to tap the SMD circuit.. :)

Will post audio as soon as it's up and running!
also show pics of the breakout modul please once you got your modified res-4 back :tu:
Picked it up today, now ordering parts so I can finish it all next week. Will definitely post details.

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Post by qu.one » Mon Sep 21, 2015 3:31 pm

echoplex wrote:
Spunny wrote::woah:

a VM-1 with an envelope breakout would be fkn swell ..
okay, now I want my BLD to have a CV input for the cutoff :yay:
isn't it already paired with another input?

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Post by Dogma » Mon Sep 21, 2015 4:00 pm

Yup thats the mod :)
i emailed Wowa - surprize never got back to me

VM-1 s such a great module but ts so non modular and t has a great EG section
look up!

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Post by echoplex » Mon Sep 21, 2015 4:36 pm

qu.one wrote:
echoplex wrote:
Spunny wrote::woah:

a VM-1 with an envelope breakout would be fkn swell ..
okay, now I want my BLD to have a CV input for the cutoff :yay:
isn't it already paired with another input?
unfortunately not :waah:

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Post by qu.one » Mon Sep 21, 2015 4:43 pm

echoplex wrote:
qu.one wrote:
echoplex wrote:
Spunny wrote::woah:

a VM-1 with an envelope breakout would be fkn swell ..
okay, now I want my BLD to have a CV input for the cutoff :yay:
isn't it already paired with another input?
unfortunately not :waah:
i haven't owned one in a while, but i went to look at the manual... i thought i controlled mine with an external inout.

LOW PASS FILTER has two audio
inputs marked OSCILLATOR LEVEL
and NOISE LEVEL, The CUTOFF
frequency is controlled manually,
transient generators AR and AHR and
by CUTOFF pre-patched to FM2 CV
input.

http://www.cwejman.net/bld-webb2.pdf

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Post by listentoaheartbeat » Wed Sep 23, 2015 2:34 pm

A couple more photos showing the wiring. I had to re-route the wires to the other side of the module so the breakout would fit my case, taking care to not put any leverage on the solder joints that tap the SMD circuit. Scary shit! :eek:

Hats off to Derek for the solder job - I would have crapped my pants doing this, and how he managed to do it so neatly is beyond me. :tu:

I added a cable relief by mounting a zip tie to the plain PCB Wowa adds to the back of his modules, in addition to securing the wires at the power socket. This should keep any leverage away from the solder joints.

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Post by Iamsofaking » Wed Sep 23, 2015 3:04 pm

Following :)

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Post by sempervirent » Wed Sep 23, 2015 10:54 pm

Modding the :cwejman: ... !?

Looking forward to audio... interesting to think of modulating the individual outs or sending through different effects sends and then mixing them back.

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Post by BugBrand » Thu Sep 24, 2015 3:39 am

Quick thought -- guessing these are probably 12db SV Filters, so I'd imagine there would be possibility to tap HP and LP from each core too.. Usually takes 3-4 opamp stages and 2 VCA stages (the 2181 - I see 2 per row, so tallies). HP is usually the input opamp sum, BP is the first integrator (opamp with cap between - and out) and LP is the 2nd integrator.

Saying that.. there is something great about sticking with the original design - one of the challenges of module design is where to draw the line with regards to possible features -- it is way too easy to add several kitchen sinks and some porta-loos too, but that can quickly lead to over-blown (though sometimes you want multi features --- it is all swings & roundabouts)

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Post by listentoaheartbeat » Thu Sep 24, 2015 6:30 am

sempervirent wrote:Modding the :cwejman: ... !?

Looking forward to audio... interesting to think of modulating the individual outs or sending through different effects sends and then mixing them back.
Yeah, I am looking forward to feedback modulation from the individual outputs, it's one of the applications I had in mind for this. And folding three stages individually with the TWF for wavefolded chords. :)
BugBrand wrote:Quick thought -- guessing these are probably 12db SV Filters, so I'd imagine there would be possibility to tap HP and LP from each core too.. Usually takes 3-4 opamp stages and 2 VCA stages (the 2181 - I see 2 per row, so tallies). HP is usually the input opamp sum, BP is the first integrator (opamp with cap between - and out) and LP is the 2nd integrator.

Saying that.. there is something great about sticking with the original design - one of the challenges of module design is where to draw the line with regards to possible features -- it is way too easy to add several kitchen sinks and some porta-loos too, but that can quickly lead to over-blown (though sometimes you want multi features --- it is all swings & roundabouts)
I agree, it's a fine line. Originally I wanted individual inputs, too, but we decided against it since it is tricky to do. Kinda glad about this, don't want to turn the concept inside out. For the same reason, I wouldn't want other filter modes. I'd start to use it more as a filter then and in my system it is primarily a sound source. Individual outputs are something I always wanted for waveshaping by feedback patching and folding of the individual channels. It covers some functional gaps in my small system in a neat way, without buying more stuff. :)

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Post by flo » Thu Sep 24, 2015 8:25 am

listentoaheartbeat wrote:Originally I wanted individual inputs
That was my first thought when I've seen the thread, something I wished for much more often than individual outs.

But, if you're honest, the problem in the end is just that you don't have the space for a QMMF4, isn't it? :hihi: ;)

Cheers :guinness:

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Post by listentoaheartbeat » Thu Sep 24, 2015 9:23 am

flo wrote:
listentoaheartbeat wrote:Originally I wanted individual inputs
That was my first thought when I've seen the thread, something I wished for much more often than individual outs.

But, if you're honest, the problem in the end is just that you don't have the space for a QMMF4, isn't it? :hihi: ;)

Cheers :guinness:
Haha, kinda.. The QMMF-4 would be overkill for my system. I've been using it at a friend's place, it's basically a complete synth. I think I prefer Res-4 + TWF. Pretty much the same size, too.

A Res-4 with individual inputs, outputs, and fine tune would be perfect. But on the other hand, who wants perfect. I think it's more interesting to work around limitations sometimes. Many of the sounds I've made with the Res-4 would not have happened if it had all those extra features.

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Post by Navs » Fri Sep 25, 2015 3:16 am

listentoaheartbeat wrote:blablabla
Stop posting here and finish that mod so we can hear what it sounds like! :lol:

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