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Post by rodney on Feb 4, 2020 23:16:44 GMT
After listening to discussions about pros and cons of AE's jumper lead patching system, and doing a gig in a dimply-lit venue without my glasses on, I'm thinking about ways to better manage patching in a live situation. I'd like to be able to re-patch a few things on the fly over the course of a live set but I don't want to go all-out and convert my AE modules into bulkier Jack or Banana plug systems.
I loved the VCS3's pin matrix and am thinking how to emulate that in miniature form for the AE. That led me to thinking that a grid of tiny push-button or toggle switches might be the answer. Toggles have the advantage of showing their state without needing LEDs etc. so could be completely passive.
That, in turn got me to think about a more space-saving approach and I found these neat little 8 position rotary switches. They are about 16mm across so, a 2unit module could accomodate 8 of them with an option to buffer them as well (although, in the latter case, I'd probably do the switching with chips as well).
Each unit would switch between 8 different inputs and feed to one output. 8 of them would give a matrix where it is not possible to connect two inputs to the same output.
A 1unit module could fit 4, possibly 5 of them.
This would allow you to wire up a few different configurations in advance then switch between them on-the-fly while performing or recording.
I think this would be the cheapest way to get this much flexibility in this little space - and only 128 connections to solder (including the headers). It could be all panel-based with wire and no circuit-board (spaghetti hell) or a nice printed circuit board with no wires anywhere.
thoughts?  |
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Post by rodney on Feb 4, 2020 23:18:04 GMT
I have not given up on the pin matrix idea either but I imagine it would be a bit fiddly to use at AE scale.
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Post by NightMachines on Feb 5, 2020 10:36:56 GMT
Great idea! That reminds me of a similar project of mine for my Klangbau Köln Eurorack synth:  I designed a 19” rack panel with eight attenuators (four of them with additional mute switches), multiples (switchable between 5 and 10 sockets), four jack converters and two three-way switches (to mute and route a signal between two ins/outs). Klangbau helped me with the panel so that it came in the same style as their steel modules. Now that you mentioned your project, rodney, I think I’ll create myself a manual switch and attenuator performance module too! |
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Post by loopier on Feb 5, 2020 20:50:32 GMT
oh, yes. What a wonderful idea. I'll join in
I've already started building a 4x4 matrix mixer after Nicolas Collins' design. It's going to be a perfect partner for this kind of modules.
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Lugia
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Post by Lugia on Feb 5, 2020 23:03:16 GMT
Matrix mixer? Yeah, count me in as well...gets my thumbs-up.
Doesn't have to be all that complex, either. Take the example of the Pro-One...it has its version of a modulation matrix, quite simple, and yet that one bit unlocks a whole WORLD of crazy. Shouldn't be too much of a stretch to do an implementation along the same lines for the AE.
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vojta
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Post by vojta on Feb 6, 2020 1:35:24 GMT
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Post by lukylutte on Feb 6, 2020 6:22:32 GMT
Didn't know about the synapsis; Thanks! Waiting for more info for this rotary things as well  |
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Post by spacedog on Feb 6, 2020 10:21:02 GMT
Wow, a couple of those and a joystick and... |
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Post by loopier on Feb 6, 2020 10:22:16 GMT
oh, didn't know about this! Nice, thanks!
It's the same idea but with pots instead of buttons, and maybe a toggle or button per row for quick silence/trigger control.
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Post by slowscape on Feb 9, 2020 16:45:54 GMT
This is arguably the best idea in the diy forum to date. Continue. 😆👍
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Post by rodney on Feb 11, 2020 0:38:17 GMT
I'm talking to people in Shenzhen (from whence all goodness flows) but this item seems to be out of stock everywhere. It may have just been a limited run but I'm trying to track down something similar. Adafruit had the same item but is listed as out of stock, so I guess they have the same problem. Sending Adafruit requests about it might motivate them to get a batch made, if enough people are interested.
I may go with a purely electronic switching setup after all, maybe 8 x CD405xB-Q1 chips , 8x8 grid of LEDs and either 8 x rotary encoders to fill the role of the selectors or 16 little pushbuttons to select along the edges of the grid.
The latter setup could also be voltage-controllable without too much extra fuss.
This would be an excuse for me to do a proper circuit-board design and get my feet wet with SMT chips etc.
... but, I'm hoping for a totally passive thing though, if these neat little switches re-appear.
While I wait, I'll concentrate on another project.
I definitely want to make this though, if the bits are available again.
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Post by rodney on Mar 10, 2020 1:27:04 GMT
The rotary thing is still out of stock AFAIK. The effect of the novel corona-virus on supply chains from china probably means that a lot of stuff will take longer to arrive than normal.
Then again, they tend to consolidate shipments anyway so things that normally take 21 days may still take about the same amount of time because items will sit idle in a warehouse until they get enough items to fill or backfill a container going to your city.
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Lugia
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Post by Lugia on Mar 10, 2020 3:08:50 GMT
One other point in favor of purely electronic switching: running it at audio rates. Manual and electromechanical can't pull that off, but the ability to "chop" in the audio frequencies opens up a new modulation possibility.
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Post by rodney on Mar 10, 2020 3:37:24 GMT
Good find! That link is dead but they still sell a few variations:
These are definitely in AE price range too and would take minimal cutting to AEify them.
That book that comes up in the search also looks interesting BTW.
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Post by rodney on Mar 10, 2020 4:25:22 GMT
Another idea I am toying with mentally is to have a matrix of magnetic reed switches then slide little magnets around on a thin steel plate above them (of course the plate must double as a theremin antenna! (it's a convergence thing, ya know?))
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Post by rodney on Mar 10, 2020 4:28:01 GMT
AND ... another approach would be to have 8 of these 8-position slide switches...
However, so far, I have only found dealers offering a minimum order of 1000 at about $200USD - good value, but I only want 8 for now thank you. 
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Post by rodney on Mar 10, 2020 5:21:49 GMT
Hey, I found a place in Greece that still has some of these little 8-way rotary switches in stock.
I bailed out because the shipping to australia was more than the price of the product (for 8 of them) but it might be a much better deal within the EU.
Let us know if you take the plunge and make a switcher with these. I'm so pissed I can't find an affordable supply of them yet.
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Post by NightMachines on Mar 10, 2020 6:36:07 GMT
Could you elaborate on the matrix idea maybe? I don’t really understand how you’d wire the eight switching pots exactly and what they’d do then.
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Post by rodney on Mar 11, 2020 9:41:50 GMT
Could you elaborate on the matrix idea maybe? I don’t really understand how you’d wire the eight switching pots exactly and what they’d do then. Ok, you have 8 x 8-way switches single pole 8 throw (SP8T) s1-s8
the throw of s1 is connected to output 1 the poles of s1 are connected to inputs 1 to 8
the throw of s2 is connected to output 2
the poles of s2 are connected to inputs 1 to 8
... and so on up to s8
So, it's not strictly a matrix as it makes sure that no output can be connected to more than one input at a time. However, one input could end up connected to several different outputs at once.
We could, of course simply plug inputs to the outputs and outputs to inputs instead, but this would lead to potentially harmful summing of voltages to above 5v, leading to possible magic smoke release events.
Although not a matrix, it would be a reasonably compact and easy to build passive routing module that you could use to quickly switch things around in a live gig without fumbling around with the patch leads.
I'd probably go the extra mile and buffer the outputs.
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Lugia
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Post by Lugia on Mar 12, 2020 3:51:07 GMT
Probably a good idea to diode-protect the inputs and outputs as well. Synths are like raccoons...you have NO IDEA how they can get into the situations they do, but by god, they DO. Best to out-think those things before they out-think you... |
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Post by rodney on Mar 12, 2020 9:19:16 GMT
Probably a good idea to diode-protect the inputs and outputs as well. Synths are like raccoons...you have NO IDEA how they can get into the situations they do, but by god, they DO. Best to out-think those things before they out-think you... You mean zeners to peg everything to 5v, no matter what happens? Very sensible.
that makes me think more about a proper matrix where nothing is forbidden but all is forgiven.
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