Understanding the WSG schematic

t1d · Joined: Apr 04, 2017 Posts: 11 Location: Alabama

I am not accustomed to seeing a particular type of notation that Mr. Wilson used on his schematic. They appear to be nets/traces that do not terminate to a component, or a pad. Are they simply names for the nets?

A sample has been highlighted with red circles. Please tell me what is going on. Thank you.

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gdavis · Posted: Mon Apr 10, 2017 9:55 pm Post subject:

If you look at the pictures of the boards on the MFOS site it looks like those labels correspond to pads on the board for connecting the pots and switches. The pads have the same labels silk screened by them.

So, for example:
R1 pin 3 would connect to the pad WK1A
R1 pins 1 and 2, S1 pin 1 and S2 pin 1 connect to pad WK2A
S1 pin 2 connects to DPSA
S2 pin 2 connects to WSWA

and so on.

It's a little confusing but I think it minimizes the amount of wiring between the board and panel.

t1d · Joined: Apr 04, 2017 Posts: 11 Location: Alabama

Thank you, gdavis, for your reply. That was my conclusion, as well. However, I find things that make me continue to question the idea... Mainly that there would be various pads missing, for the off-board wiring.

For example, the Wacky Frequency pot and the Wacky Too switch are wired off-board and return to the board at pin #1 of the Wackiness switch. There is not a pin labeled for this return, if this is the correct interpretation of the labeling convention.

t1d · Joined: Apr 04, 2017 Posts: 11 Location: Alabama

Hmm... Maybe I see it better, now... WK1A serves all three, the pot and the two switches...

t1d · Joined: Apr 04, 2017 Posts: 11 Location: Alabama

What about the circle with "ODD" inside? Might that be a network flag?

gdavis · Posted: Tue Apr 11, 2017 12:32 am Post subject:

Grumble · Posted: Tue Apr 11, 2017 12:36 am Post subject:

My guess is that it's an input for a second unit.
There is another thread on this forum about this module: http://electro-music.com/forum/topic-42077.html

and/or read: http://musicfromouterspace.com/analogsynth_new/WSG2010/wsg_page2.html

gdavis · Posted: Tue Apr 11, 2017 10:54 am Post subject:

t1d · Joined: Apr 04, 2017 Posts: 11 Location: Alabama

Thank you, to all. Very good information...

I am wittlin' down the schematic. The off-board components will only be annotated. The reason to need to do the thinning is that I am working in KiCad... And, KiCad makes associations between what is in the schematic and what is on the board. So, if it's not going to be on the board, it does not need to be an ("active") item on the schematic.

If someone would help me proof my work, I would be willing to post the KiCad schematic, on this forum, for others to use. It would save them a world of work. I am close to having it completed. I can provided it as a pdf, so having KiCad would not be necessary. Any takers?

My brother and I are retired and have taken up electronics to keep our brains sharp. We built a Reflow Oven and I will be doing this project with SMD components. Kewl!, as the cool kids say...

elmegil · Posted: Wed Apr 12, 2017 10:10 pm Post subject:

Ray had no objections to people making their own PCBs in whatever fashion, stripboard, CAD, etc, but I do believe he drew the line at public posting of CAD that could just be shipped off to a fab to do mass PCB runs. Not that such is your intent, I think you're clear about that, but if you post the CAD publicly, someone who is less scrupulous may well take advantage of that.

Synthcube arrived at an arrangement with Ray's estate to keep his PCBs in print, so if someone wants an off-the-shelf PCB they ought to be able to go there to purchase one, and part of that money goes back to Ray's family. He has them in stock right now for $15:

http://synthcube.com/cart/music-from-outer-space/noise-boxes/mfos-weird-sound-generator

And for a little more you can get a panel to go with it.

I don't want to discourage you from working with KiCad on this, that sounds like a great project in several dimensions. But I would suggest it would be better not to post the CAD files.

elmegil · Posted: Wed Apr 12, 2017 10:12 pm Post subject:

OH, and if you're doing it SMD, small format, you might talk to Synthcube to see if he wants to pay you for the layout Very Happy

I think there are people who would be quite interested in a Euro-compatible WSG for example (though you might want to incorporate some of the CV-able mods that are mentioned on Ray's website for that to be really compelling).