Getting started building CGS modules [Build Thread]

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

I've been planning out my next diy project and have been absolutely enticed by CGS modules. Every single module seems to have tons of extra features, and I'd like to start building them, but how do you make the pcbs? most other diy synth sites such as MFOS and Yusynth have images for the pcb traces so you can etch them at home, I haven't been able to find such files on the CGS site. Normally I'd be fine buying pcbs, but most sites seem to be out of stock of many modules, and most sites are missing certain pcbs entirely. Worst scenario I suppose I'll have to perf-board some modules, which isn't too bad.

I've also been considering documenting my CGS build here if that is okay. I've started designing the panel graphics and layout for a few of the modules. I'm planning on building it into an aluminum suitcase.

The attachment (which I hope worked) is what I have so far for my panels. It's going to be in the eurorack format, powered by +/-15v, with the visual style of buchla modules. That's the plan anyway. For some reason when I exported the file, the text changed. The actual text will be slightly more bolded and italicized, much more reminiscent of buchla text.

CGS PANEL.pdf

Description:

Download (listen)

Filename:

CGS PANEL.pdf

Filesize:

349.02 KB

Downloaded:

1187 Time(s)

gabbagabi · Posted: Tue Oct 03, 2017 8:51 am Post subject:

hi,

MFOS and yusynth had decided to share there pcb artworks, others for some reasons not. thats quite common.
if you look one the huge amount of modules to buy where u will never see even a schematic - u can be quite happy to have at least the schematic available- at least you could choose to do it on stripboard or design pcbs on your own (and may get the permission to share them, if u need a permission, iam not shure in this point).

You have done well to start with designing the panels, it very helpfull to have a fixed reference point to avoid problems later when you are in the board building phase.

I guess everybody would be happy to see the documentation of your build here, the hard work from others is often a precious source of inspiration.

good luck for your build!

PHOBoS

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

Thanks for the feedback. I've started redesigning the VCO pcb with the same layout as the original. It's going to take quite a while to do this with all the pcbs I plan on making, but I can make them downloadable once I'm done, as long as that's okay with Ken Stone anyways. I'll probably be perf-boarding the more simple modules such as the Utility LFO. This build will likely end up being a long, drawn-out project since I'm in school and don't have too much time. Here's a list of all the modules I'm planning on building so far:
2x VCO
1x Bi-N-Tic (I don't really understand this thing, but it sounds cool)
1x Triple Wavefolder
1x Dual Utility LFO
2x VCA
1x DUSG
(maybe) 1x ADSR
1x Sequencer/Programmer
(maybe) 1x Infinite Melody
1x Digital Noise (may substitute it for a different noise module)
1x Mixer/Phaser
1x reverb
(maybe) 1x VCF of some sort, maybe the Dual Wasp
As mentioned, it will be built with eurorack dimensions, so I may end up buying a touch plate keyboard such as Sputnik's to use with it.

It's a pretty ambitious list, so I may end up trimming some things. If there are any "must have" modules that I am missing, or ones that could be cut from the list, feel free to chime in.

gabbagabi · Posted: Wed Oct 04, 2017 1:46 am Post subject:

hm,
i guesss u will spend some time with that list Smile

Thanks for reminding me on the BNTIC, which is now back on my radar.

You will make the pcbs panelmount?

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

^ The pcbs will have the exact same layout, so all of the designators and wiring diagrams will still be relevant, they will have mounting holes, but will not have the pots and jacks soldered directly to the board if that is what you are asking.

wackelpeter · Posted: Wed Oct 04, 2017 6:52 am Post subject:

Heavy stripboarding addicted here... I have build many of the CGS modules on stripboard and well it's a lot of work but rewarding.

If i can amke some suggestions i would Switch the bi-ni-tic VCf for a serge 1973 VCF which sounds really cool, haven't heard the Bi-Ni-Tic yet, but some say it's okay but not impressive... perhaps a point of view and preferences.

Also i would left the LFO out and replace it with an DUSG or VCS, same for the ADSR...

Having 6 VCS and a DUSG i would say you can't have enough of them and they are capable of most of the duties of the aformentioned modules...
I use them insantly as LFO and EG and also as a less accurate VCO... Then you can use them as divider, VCF and, and, and.... it's something like a swiss pocket knife in the synth world.

P.S. Regarding the Reverb i don't like the Sound of mine that much, it's not strictly the CGS Version but uses the same branch of digital reverb... therefore i would go ahead for a real spring reverb.

Here's a list of my favourite CGS modules:
VCS of Course
DUSG
Serge 1973 VCF
Smooth & Stepped Generator
Analog Switches
CV Processor
Serge VC ADSR
Serge Resonant EQ
Phaser
Psycho LFO
Gate Sequencer
Pulse Divider
Burst Generator
Negative Slew
Serge 1973 EG
CV Cluster
and of course Mixers... a lot of them...

Also have the Slope Detector (which i rarely use), Master Divider, Gate to trigger (10 or so) and the VC Clock Divider, BPF, Joystick Controller, Steiner VCF, Wasp VCF, Serge Noise, Comparator, Gated Comparator, guess i still forgot something

Yep, i forgot the VCA... it's a nice VCA, beside the Thomas Henry VCA1 one of my favourite VCA's

Skrog Productions · Posted: Wed Oct 04, 2017 10:47 am Post subject:

Hello

I have built a few CGS modules over the years most were pcb's bought from Ken Stone with the odd build on veroboard Smile

.

Dual steiner vcf's http://electro-music.com/forum/topic-61646.html

Dual gate sequencer http://electro-music.com/forum/topic-61572.html

psycho lfo / burst generator / analog switch matrix / digi-noise gen / cynares cymbal snare drum too .

Study the build documents over and over before starting as there are different options on some of the projects for inputs / outputs.

Good luck Smile

Dave.

PHOBoS · Posted: Wed Oct 04, 2017 12:13 pm Post subject:

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

^^ Very nice builds Skrog Productions That's a pretty crazy DIY modular you have built, I just glanced through those threads now but I'll take a more careful read through them later. It's nice to see what features other people choose to implement!

And thanks for the suggestions wackelpeter. Do you find that the extra features on the VCS makes it worth building over the DUSG? I watched a few demos of the 73 VCF and it sounds really, really nice (I'm a huge sucker for different filter types). I still want to build a Bi-N-Tic out of curiosity, so might just have to do both. Also, thanks for the heads up on the reverb, I was a bit curious about that as I haven't seen that kind of compact reverb before. I have a spare spring tank lying around that I pulled from an organ, so I may build a MFOS VC-Spring Reverb.

I should hopefully have the VCO pcb image done by tonight.

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

wackelpeter · Posted: Wed Oct 04, 2017 1:16 pm Post subject:

Regarding the reverb i remember thant Fonik also did a module with that Kind of reverb... as far as i remember that sounded a lot better than mine...

But maybe i'm a bit too biased on this Topic as i heavily fell in love with my reel to reel tape delay... A Philips i modified for different tape Speeds and thus different delay times...

here's a link: https://www.youtube.com/watch?v=pwSgzowymQE

Well the VCS has the advantage that you have simultaneously individual and separate control over rise and fall times... At the DUSG you can Control either fall, rise or both with only one CV Input were you select with a Switch one of these 3 Options.

Also the VCS has swithces for linear or log Operation... btw. when designing your own Panels i have also brought the inverted end of cycle output to the panel... that's the one spare part of the LM3900 unconnected in the schematics...

and when Building the phaser... maybe try out on breadboard first to power the vactrols with Scott Stites Control section for his vactrols in his Phaser and Mutant filter... Got very good results with only consuming 2-3mA and it's much easier to build and afterwards a bit trimmable and saves you the hunt for obsolete CA3046 or CA3086.

wackelpeter · Posted: Wed Oct 04, 2017 1:21 pm Post subject:

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

I've never needed so many mixers in my MU modular, but I can see how having more cv generators and modifiers here in serge would require them. I'll make sure I have more than two mixers. I'll take a look at the Buchla Timbre/Crossfader circuit. I've already checked about the CA3046 and CA3086 and smallbear has both, so I'm not too concerned about those.

I just finished the VCO pcb, I haven't built it yet so it may have a few mistakes (hopefully not). I just messaged Ken to make sure he's cool with it.

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

The Buchla Timbre/Crossfader circuit looks really cool. I may decide to incorporate that into each VCO to make it more like a Buchla system. I just want to make sure I'm looking at the right circuit, is this it? http://modularsynthesis.com/lanterman/timbre-crossfader/timbre-crossfader.htm

Here's the CGS VCO pcb for you to etch at home, I don't know how to make it a pdf so that it's in the right scale, so you may have to play around with it for a bit to get the image the right size. I haven't tested it myself yet so there may be mistakes (hopefully not).
Edit: Mistakes corrected

CGS VCO pcb.jpg

Description:

Filesize:

445.28 KB

Viewed:

650 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

Here's the CGS DUSG pcb. Again, there may be mistakes as I haven't tested it yet (I'll get around to etching and building these all myself once I've finished all the pcbs I plan on doing). What do all of you think about starting a separate topic specifically for all the pcb layouts, so that people won't have to sift through this build thread?
Edit: Mistakes fixed

CGS DUSG pcb.gif

Description:

Filesize:

51.32 KB

Viewed:

674 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.

gabbagabi · Posted: Mon Oct 09, 2017 6:46 am Post subject:

wow, thats looking good!

You can make a PDF document with all the pcb layouts and put it in your first post.

edit: it really would be good if you can make pdf's. Normally every Layout program can printout the pcb layout, ether directly or you install first a pdf printer (eg PDF24), or use the microsoft xps printer option, (from xps to pdf it is only a few clicks)

haebbmaster · Posted: Mon Oct 09, 2017 7:10 am Post subject:

This ist great work you're doing here. Thank you.
I already did 3 USGs on perfboards, but I will use your layouts now.

I don't think you should make another thread, so we have all in one place here

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

haebbmaster · Posted: Sat Nov 04, 2017 1:09 pm Post subject:

Thank you!!!!
It Works!

vco1.jpg

Description:

Filesize:

104.24 KB

Viewed:

565 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

!!!! I'm really glad that it turned out good. Looks great Very Happy

On a side note, sorry I haven't posted anything lately. I did start experimenting with silk-screening panels, but haven't got any near satisfactory results, nothing worth posting anyways.

haebbmaster · Posted: Sun Nov 05, 2017 12:00 am Post subject:

For those about to build:

There is a wire jumper that is not mentioned in the building instructions (at least I couldn't find it) and I didn't understand what it means when I looked at the picture. There are no holes for this.
Without this, nothing happens at all!

Perhaps you could insert a track here in the pcb (after checking wheter I'm right, please)

sergetp.jpg

Description:

Filesize:

105.46 KB

Viewed:

26460 Time(s)

sergetp1.jpg

Description:

Filesize:

15.17 KB

Viewed:

26460 Time(s)

sergetp2.jpg

Description:

Filesize:

52.13 KB

Viewed:

26461 Time(s)

Hubaswift · Joined: Jul 06, 2016 Posts: 91 Location: Canada

Yea, looks like a mistake on my part. Thanks for the heads up. I went back and edited the post to include this track.

haebbmaster · Posted: Sun Nov 05, 2017 10:20 am Post subject:

No, it's a problem of the original PCB. Thanks for correcting.

haebbmaster · Posted: Sun Nov 05, 2017 11:44 am Post subject:

So, for the DUSG:

You have to make two cuts on your PCB. The original of Ken Stone is a bit confusing here. Looks like he made these cuts afterwards too.

You can check for shorts with the fill function of your paint program.

Hubaswift DUSG.jpg

Description:

Filesize:

696.85 KB

Viewed:

613 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.

DUSG 5.11.2017 19.jpg

Description:

Filesize:

118.37 KB

Viewed:

519 Time(s)

This image has been reduced to fit the page. Click on it to enlarge.