Pure GMSN! Range

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: luketeaford, Joe., lisa, Kent

User avatar
GBR303
Common Wiggler
Posts: 145
Joined: Mon Jun 30, 2014 12:59 am
Location: Glasgow

Pure GMSN! Range

Post by GBR303 » Sun Jun 28, 2015 11:49 am

Hi guys, I've been working on a range for modules for the synth DIY group I run and I guess I should post something about them here :)

The thinking behind the Pure range is to strip everything back to the bare essentials. When people are just getting into synths the sheer number of features on some modules can be overwhelming. It's also all about Synth DIY so the boards are laid out cleanly making component population and soldering easier.

Full build docs will go up on the gmsn.co.uk website shortly, which will include step by step instructions with colour photos, schematics showing expected voltages and signals at various test points and a full explanation of how the module works. The aim is to share the knowledge and give people a good insight into the world of Synth DIY.

A rather rubbish demo video can be found here: https://vimeo.com/gmsn/puredemo

Here's some photos of the boards. The VCA one needed some updates, hence the air wires, etc:

Pure VCO:
Image

Pure Sine VCF:
Image

Pure VCA: (ignore the airwires, the PCB has been updated :))
Image

Pure LFO:
Image

They're all available as either PCB, PCB & Panel, Full Kit or Pre-built, tested and calibrated from gmsn.co.uk/shop

Grumskiz
Wiggling with Experience
Posts: 346
Joined: Thu Apr 03, 2014 12:51 pm
Location: Germany

Post by Grumskiz » Sun Jun 28, 2015 3:14 pm

That looks like a promising module series. I'm very interested in the filter and hope to see more!
Only a small bit of criticism: 9mm pots only seems limiting. I find 16mm to be easier to source and also usually much cheaper. Is there a possibility of a multi-footprint that can take both 9mm and 16mm pots for future designs?

User avatar
Shoggoth
Common Wiggler
Posts: 222
Joined: Sat Aug 10, 2013 6:51 am
Location: Richmond, VA

Post by Shoggoth » Sun Jun 28, 2015 4:03 pm

I said it in the Synth DIY FB group and I'll say it here: these look great! Those board layouts are really clean with ample space between components.

User avatar
ilya.n
Common Wiggler
Posts: 142
Joined: Wed Oct 01, 2014 7:57 pm
Location: Sydney, Australia

Post by ilya.n » Sun Jun 28, 2015 7:36 pm

Great stuff!

Coudn't find "add to cart" button on the website though. Is it just me or it's not working?

User avatar
GBR303
Common Wiggler
Posts: 145
Joined: Mon Jun 30, 2014 12:59 am
Location: Glasgow

Post by GBR303 » Wed Jul 01, 2015 2:07 pm

Grumskiz wrote:That looks like a promising module series. I'm very interested in the filter and hope to see more!
Only a small bit of criticism: 9mm pots only seems limiting. I find 16mm to be easier to source and also usually much cheaper. Is there a possibility of a multi-footprint that can take both 9mm and 16mm pots for future designs?
Hey, thanks. I went for 9mm as it's a bit neater behind the panel and means I can shave a couple of hp off. I didn't want to clutter the layout by having different options and Thonk have a good supply of them.

Thanks Shoggoth! That's very kind of you :)

ilya.n - There was an issue with the shipping on the website, but that's been resolved now. Let me know if it's not working.

BTW: Build docs will be added very shortly. I'll update when they're up.

autowitch
Learning to Wiggle
Posts: 8
Joined: Tue Aug 06, 2013 5:46 pm

Post by autowitch » Wed Jul 01, 2015 3:41 pm

These look pretty cool. I just ordered some. I'm still a bit of a n00b, so this is exactly what I've been looking for.

-aw

User avatar
GBR303
Common Wiggler
Posts: 145
Joined: Mon Jun 30, 2014 12:59 am
Location: Glasgow

Post by GBR303 » Thu Jul 02, 2015 4:46 pm

autowitch wrote:These look pretty cool. I just ordered some. I'm still a bit of a n00b, so this is exactly what I've been looking for.

-aw
Hey, can't see you're order in the system?

BTW: Pure GMSN! Build Doc is now online, complete with full colour step by step instructions and full test plan:

GMSN! Support Docs

User avatar
cane creek
Ultra Wiggler
Posts: 875
Joined: Sat May 26, 2012 1:12 am
Location: Middlesbrough UK

Post by cane creek » Sun Jun 05, 2016 2:57 pm

Just noticed the Pure Quantiser on modular grid

Image

User avatar
GryphonP3
Super Deluxe Wiggler
Posts: 1093
Joined: Tue Jan 29, 2013 3:20 pm
Location: Los Angeles

Post by GryphonP3 » Sun Jun 05, 2016 3:02 pm

cane creek wrote:Just noticed the Pure Quantiser on modular grid

Image
Wow, looks like a good one! All great value on these modules, the quantizer looks especially nice. I like the on board slew touch :)
My cat can eat a whole watermelon ...

User avatar
Bamboombaps
Wiggling with Experience
Posts: 398
Joined: Wed Sep 16, 2015 7:14 am
Location: Glasgow

Post by Bamboombaps » Sun Jun 05, 2016 7:10 pm

i reckon we wil see this one first http://gmsn.co.uk/product/gmsn-pure-sequencer/

:mrgreen:

User avatar
Bamboombaps
Wiggling with Experience
Posts: 398
Joined: Wed Sep 16, 2015 7:14 am
Location: Glasgow

Post by Bamboombaps » Tue Jun 21, 2016 1:53 pm

the main site has been updated with the new quantiser and sequencer. tidy wee cases too.

http://gmsn.co.uk/products/

User avatar
br1qbat
Common Wiggler
Posts: 81
Joined: Sat May 28, 2016 10:26 am

Post by br1qbat » Tue Jun 21, 2016 7:12 pm

YAY :nana: :nana: :sb: :party:

User avatar
trimix
Learning to Wiggle
Posts: 48
Joined: Fri Nov 20, 2015 3:32 am
Location: Nanoose Bay, Canada

GMSN Schematics?

Post by trimix » Sun Feb 05, 2017 1:46 pm

GBR303
Hey Rob - Sorry to hear about the troubles with the shop - I'm confused about whether it's running or not. Good luck!
I can't find any working links online, however. I've sat down to start assembling your Pure (is that a Weegie "Pure" or a "clean" Pure? ;))VCO and Pitch Quantiser modules and I usually use the schematics as I build SMD projects.
Do you have GitHub files or Eagle files with schematics I could use for those two boards?
Thanks mate!

Update: Schematics aren't too critical unless the board doesn't work for me...But I really could use the Firmware files, calibration procedures, etc.
Really wishing I had downloaded when I bought the PCBs

User avatar
brandonlogic
Super Deluxe Wiggler
Posts: 2671
Joined: Tue Jan 27, 2015 9:17 am

Re: GMSN Schematics?

Post by brandonlogic » Tue Apr 04, 2017 7:54 pm

Image

im looking for a bom and guide for this version of the pure vca.
does anyone have one by any chance?
the website only has the new version.

User avatar
Bamboombaps
Wiggling with Experience
Posts: 398
Joined: Wed Sep 16, 2015 7:14 am
Location: Glasgow

Re: GMSN Schematics?

Post by Bamboombaps » Wed Apr 05, 2017 8:53 am

trimix wrote:GBR303
Hey Rob - Sorry to hear about the troubles with the shop - I'm confused about whether it's running or not. Good luck!
I can't find any working links online, however. I've sat down to start assembling your Pure (is that a Weegie "Pure" or a "clean" Pure? ;))VCO and Pitch Quantiser modules and I usually use the schematics as I build SMD projects.
Do you have GitHub files or Eagle files with schematics I could use for those two boards?
Thanks mate!

Update: Schematics aren't too critical unless the board doesn't work for me...But I really could use the Firmware files, calibration procedures, etc.
Really wishing I had downloaded when I bought the PCBs
does this page have what you are looking for?https://gmsn.co.uk/products/gmsn-pure-vca

User avatar
okelk
Wiggling with Experience
Posts: 456
Joined: Mon Jan 13, 2014 4:16 am
Location: Vienna, Austria

Re: GMSN Schematics?

Post by okelk » Wed Apr 05, 2017 4:46 pm

Bamboombaps wrote: does this page have what you are looking for?https://gmsn.co.uk/products/gmsn-pure-vca
The SMT versions may be slightly different...
The build manuals for the old though hole stuff aren't online anymore...

...just contact GMSN on facebook...I had the same problem with the VCO...he sent me the build manual on the same day...

workingklass0
Learning to Wiggle
Posts: 14
Joined: Thu Mar 23, 2017 10:53 pm

Build Instructions

Post by workingklass0 » Sun Apr 09, 2017 1:20 am

When are you planning on posting the build instructions? I am interested in building the Pure Sequencer.

User avatar
BillLynes
Common Wiggler
Posts: 114
Joined: Sat Nov 18, 2017 4:35 pm
Location: Everett WA
Contact:

Re: GMSN Schematics?

Post by BillLynes » Tue Dec 19, 2017 6:46 pm

brandonlogic wrote:Image

im looking for a bom and guide for this version of the pure vca.
does anyone have one by any chance?
the website only has the new version.
I have the same PCB. I think you will need a surfboard to mount IC1.

User avatar
BillLynes
Common Wiggler
Posts: 114
Joined: Sat Nov 18, 2017 4:35 pm
Location: Everett WA
Contact:

Post by BillLynes » Tue Dec 19, 2017 6:50 pm

This one should work with the THAT2181CS09 chip.

https://www.digikey.com/catalog/en/part ... ries/10390

User avatar
FetidEye
demonic space drone
Posts: 2100
Joined: Mon Dec 06, 2010 5:00 pm
Location: Red Zone
Contact:

Post by FetidEye » Wed Dec 20, 2017 4:58 am

I like these open source modules!
Very good for learning and trying stuff out! Thanks!!

Do you still have the through hole files of the modules somewhere?
I was planning to build the VCO (and adapt some idea's of mine into it. but I like TH better.

grtz. Martijn

User avatar
rsholmes
Learning to Wiggle
Posts: 38
Joined: Sat Dec 01, 2018 5:08 pm
Location: Syracuse, NY
Contact:

Re: GMSN Schematics?

Post by rsholmes » Mon Mar 18, 2019 5:56 pm

brandonlogic wrote:Image

im looking for a bom and guide for this version of the pure vca.
does anyone have one by any chance?
the website only has the new version.
I'm looking for the same thing — BOM for the Pure VCA 2.1 through hole. The website's gone of course, and the BOM is not at https://github.com/pixiemars/GMSNPure.

User avatar
rsholmes
Learning to Wiggle
Posts: 38
Joined: Sat Dec 01, 2018 5:08 pm
Location: Syracuse, NY
Contact:

Post by rsholmes » Mon Mar 18, 2019 6:11 pm

Ah, found it on the detestable Scribd: https://www.scribd.com/document/3441599 ... c-20150814

(I refuse to pay leeches.)

User avatar
khakifridge
Veteran Wiggler
Posts: 723
Joined: Wed Jun 11, 2014 2:56 pm
Location: UK

Post by khakifridge » Tue Mar 19, 2019 3:13 am

Is this less detestable?
You do not have the required permissions to view the files attached to this post.

User avatar
rsholmes
Learning to Wiggle
Posts: 38
Joined: Sat Dec 01, 2018 5:08 pm
Location: Syracuse, NY
Contact:

Post by rsholmes » Tue Mar 19, 2019 6:50 am

Much!

simoneno
1-Post Wiggler
Posts: 1
Joined: Fri Sep 06, 2019 4:52 am

Post by simoneno » Sun Sep 08, 2019 4:32 am

hello, does anyone know if there is also a guide for pure S&H?

Post Reply

Return to “Music Tech DIY”