CGS01 Sub Oscillator Questions [RESOLVED]

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Flareless
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CGS01 Sub Oscillator Questions [RESOLVED]

Post by Flareless » Wed Jan 20, 2016 8:11 am

PREQUEL:

I have posted the following questions on Electro-Music's Ken Stone forum, however, after over 220 views have received very limited support. I am re-posting it here hoping to wiggle an answer out of some of the knowledgable builders on this site. :hail:

NOTE: I understand now that the empty holes of which I will speak are for strain-relief. The other questions are the real show-stoppers for me.

___________________________________________________________

I'm nearing completion of my CGS01 but I've run into several questions which have put the brakes on the build. First I must apologize if I'm missing something obvious as I'm a new DIY builder with VERY limited electronics knowledge;

My first questions is about the jumper leads. I have installed the one below the 4030 and one by the ferrite bead. When I look at the build diagram on Ken's page, however, it appears there are more that are required...

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On the right side of the board it looks like one should be installed at the IOUT and LEVEL* locations. Additionally there are what appear to be jumpers required in the centre of the board at Channel A (1,2,3) and below that at 0,7,6,5,4. There are also a pile at the mixer section. What confuses me is that on the underside of my PCB there are no solder pads at most of these locations. Only holes.

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The IOUT and LEVEL* sections do have 2 available pads (left side of the photo), however, they are separated by holes without pads as well. Do I require more jumpers? If so... where?

My second question is What's up with all those holes?!? They seem to serve no purpose?

My final question involves the potentiometers. My intention is to wire the Version 2 board with 8 potentiometers and 3 toggle switches. The trouble is that the diagram indicating wiring of the potentiometers does not match the version of the board I am using.

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In the centre of this diagram the switches are wired to "Channel B". My PCB and the above PCB diagram have this labelled as "Channel A". Even the right side of this diagram has different resistor values; 2x1K and 1x47K versus 1x330R and 1x47K. Do I wire the \1, \2, \4 and \8 pots only? Is the centre label on this diagram wrong and these are actually Channel A pots? My intention is to wire MOLEX connectors to the potentiometer connections so I can more easily remove the PCB from the panel should there be a problem (plus I feel it's tidier and more sturdy) so I want to make sure I put them in the right place.

Thanks for reading this and I would greatly appreciate any help you can provide. I apologize again for my naiveté as a builder.
Last edited by Flareless on Thu Feb 04, 2016 8:06 am, edited 1 time in total.
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Post by kindredlost » Wed Jan 20, 2016 9:06 am

I will attempt to offer a very limited response on this one.

It has been years since I built these modules. I do know the "holes" are looms for the wire to have some stress relief. Ken does this on almost all his boards. You pass the wire through, bend it back down to the solder pad hole and solder it to the pad as usual. Be careful of the fragile pads on these boards. They are notoriously thin and can be damaged easily.

The wiring scheme is another ballgame. Since I am at work and don't have access to my own module for reference, I'll stay clear of any definitive answers to your wiring questions for now.

I do remember crossing all these ideas as well on my journey to build this module. For a starting module you have picked one of the hardest to do. The Sub-oscillator is a wonderful module though so if you have the persistence then it will pay off. I have used mine to make quite a few pleasing patches over the years. I built three of them and sold two. My builds were quite messy and didn't use the rotary switch, mixer or multiplier pots. I opted for the "alternate layout" described by Ken. It was much easier to build and works great.

Here is a panel layout I designed and Ben Marshall at Re:Synthesis builds and sells for this...

http://bigbluewave.co.uk/resynthesis/re ... panels.htm

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...and here is an old video after I first put it to use. This is an example of the "Harmonic Sequencer" function.

[video][/video]

Good luck with your endeavor. It is a truly one of the most under-rated and less known but completely unique modules ever designed.

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Re: CGS01 Sub Oscillator Questions

Post by keninverse » Wed Jan 20, 2016 9:55 am

As you stated earlier the extra holes are just used as strain relief to pass through wire from under the board. Disclosure...I've never built the board but I've built many of Ken's projects.
Flareless wrote: In the centre of this diagram the switches are wired to "Channel B". My PCB and the above PCB diagram have this labelled as "Channel A".
The wiring diagram looks like it was labelled incorrectly. I'm sure Ken is aware of this and you may want to contact him directly but if you take a look at the schematics and follow the traces on Ch. A's 4024 you'll find the wiring diagram should be labeled "A".
Flareless wrote: Even the right side of this diagram has different resistor values; 2x1K and 1x47K versus 1x330R and 1x47K. Do I wire the \1, \2, \4 and \8 pots only? Is the centre label on this diagram wrong and these are actually Channel A pots?
The wiring diagram was possibly designed for an earlier version of the board. I'm sure Ken just posted this diagram just to show an example and he states later: Wiring for the earlier version of the board is essentially the same, though the pads will be in different locations. Follow the board revision's BOM and you should be fine.
Flareless wrote:My intention is to wire MOLEX connectors to the potentiometer connections so I can more easily remove the PCB from the panel should there be a problem (plus I feel it's tidier and more sturdy) so I want to make sure I put them in the right place.


I used to put headers on everything but there's nothing wiring direct to board. The connection is direct which translates to fewer points of failure. But there's nothing wrong with headers. Just be really careful when pulling off the header...it's really easy to lift pads on these boards. Maybe consider using a header that does not use a friction lock.

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Post by Flareless » Wed Jan 20, 2016 3:11 pm

Thank you so much for the tips guys!

I found the module itself was not too tricky to build up to the point where I got to the off-board wiring. I plan to use the panel design which Ken has listed as Version 2 at the bottom of his build page. It's slightly different than the one from Re: Synthesis (which is very nice!).

So far I've built a PAiA 9700, Oakley Dual LFO, Ring Modulator and Multimixer, Moogah SEM VCF (SMD = Fun :eek: ) and Yusynth Minimoog Filter. I have to say this module is the trickiest build yet! While the design is great, the board quality isn't as great as I hoped for. I might just take Keninverse's advice and wire directly to the board.

Thanks for the video and the tips Kindredlost! I saw that video already and it helped me decide on the board. The module really has some great features.

Once again thanks so much for your quick and helpful responses. I'm off to the wiring pit to see what I can do. I'll keep you posted!
Last edited by Flareless on Thu Jan 21, 2016 10:22 am, edited 2 times in total.
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Post by kindredlost » Wed Jan 20, 2016 4:54 pm

Sounds as if you are on your way here. Great!

I started building synths with the PAIA P4700J Kit. I also have built some of Oakley modules and Yusynth stuff. I really like the Minimoog filter. Did you opt for the matched transistor ladder or the chip? I built both and have noticed a difference. I made a comparison video but you can find it among the YouTube list on my channel.

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Post by Flareless » Thu Jan 21, 2016 10:34 am

I built the matched transistor version. Lots of fun building a transistor matcher and sifting through a pile of 547s :roll:

Great comparison video. Funny.... I didn't realize how many of your videos I had already watched. Very inspirational! Subscribed now :tu:
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Post by Flareless » Thu Jan 28, 2016 9:39 pm

@Kindredlost - I was wondering if you had any diagrams or photos of your wiring for the panel you designed. That's the version I was planning on building as well. I like your design for the "alternate" panel better than the version on Ken's site.

Unfortunately RE Synthesis isn't taking orders right now so I'm going to have the panel screened myself.

I've used Ken's diagram to install the flying wires for the Input and Output jacks as well as the two switches listed. I'm not quite sure how to wire the third switch in and which wires on the diagram go where for this style of build.

Building and wiring the panel so far hasn't been a big problem for me. It's just interpreting the design. I really have to work on my schematic reading skills! If you have any more details I'd really appreciate it.
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Post by Flareless » Wed Feb 03, 2016 2:42 pm

SUCCESS!

I figured out the wiring for the Alternate version of the CGS01. It's all wired up and it tested out ok. Wow!!! I only tested it for a couple of minutes but it produced some cool sounds and patterns. I can't wait to work with it for some time.

Unfortunately I need a panel :cry:

I've done a slight modification on the design produced by Kindredlost and I'm going to have a screen made so I can produce the panel myself. Once that's done I'll mount the board in the panel and start playing.

I don't like messing around with boards too much when they're in this state...

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I'll keep y'all posted!
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Post by Flareless » Fri Feb 26, 2016 10:13 pm

Well it's been a few weeks but today I received the silkscreen with my panel design for the CGS01. As I mentioned earlier it's a modification of Kindredlost's design (thanks man!) coupled with Ken's Version 2 design from his website.

My first experiment with silkscreening didn't go perfectly but what I produced works ok for my own personal prototype version. I also learned what mistakes I made during the screening process so I won't make them a second time. These included leaving a millimetre between the screen and the panel, not using consistent pressure from top to bottom and not adequately securing the panel. Fortunately the screen itself cleaned up nicely and I'll be able to make more panels more accurately.

I also have to replace the screws which mount the panel to the board with black ones plus I have to replace the knobs with 25mm versions.

As for the CGS01 itself... holy crap!!!! I only spent a little while with it using some of Ken's suggestions for use but in that time I learned a lot about it and can see its potential as a damn cool module that I will use often. This weekend I'll spend some more time with it and post some sounds.

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Re: CGS01 Sub Oscillator Questions [RESOLVED]

Post by smartwentcrazy » Wed Jun 24, 2020 6:01 pm

I have recently bought a parts kit for one of these same CGS units - thanks so much for your thread here. It seriously gives me more info than anything I have found in weeks of looking for info on the web. Like you, I am someone with very little experience with these things (and, apart from just understanding lines, I can't really understand a schematic to save my life). Here's hoping my build goes well. It's a true DIY with a piece of aluminum I will be drilling in for the front panel. I'm hoping to mount the finished unit off rack in a small cigar box or something. Fingers crossed.

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Re: CGS01 Sub Oscillator Questions [RESOLVED]

Post by Flareless » Wed Jun 24, 2020 6:35 pm

Check out this article. It contains even more details than this thread.

Good luck with your build!
Rich

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What can this strange device be? When I touch it, it gives forth a sound - Neil Peart

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