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new voodoo
Joined: May 06, 2013 Posts: 94 Location: RVA USA
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Posted: Mon Jul 01, 2013 6:52 am Post subject:
adding a keyboard/attaching bent keys to 40106CMOS synth Subject description: Ideas on how to use a keyboard from toy to control freq or pitch on analog synth made from 40106 chi |
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Ideas on how to use a keyboard from toy to control freq or pitch on analog synth made from 40106 chip?
Ive got a keyboard with 2 octaves (16 keys) and it already has a system of tactile switches and wires coming from each key.
Ive gotten this far:
-i figure I can use a bunch of resistors, calculate values corresponding with specific intervals, and if I send the signal into the switches, whenever one is pressed, it will go through that particular resistor and alter correspondingly (different for each, hopefully in a uniform fashion)
-Problem with this: if this even works, I will only be altering the pitch, but
the keys wont turn the overall sound off/on like real keys would.
Anyways, Im hoping someone here has either tried this before or seen it done, or even knows a link to a page or tutorial or schematic describing a similar effort.
Thanks in advance for any help you can provide.
ps-before you ask, I dont have a schematic of the synth, I started sketching one, but it got fairly complicated and became way too messy to be of use (essentially its two 40106 chips, with 4 sources from each, with individual AND combined outs as well as a mixer, preamp, various low-rent effects like clipping and pt2399 delay and ht8950 modulation as well as a section with 9-pole rotary switches (x2) with 18 various capacitors, LDRs, sliders & softpot, illuminated pots w/led corresponding to modulation, etc etc..so its a mess. But really neat I think (24 switches, the 2 rotary pots, 18 other pots, 2 sliding pots, one softpot strip, 2 thumb joysticks, etc)
anyways, please help if you can, I would greatly appreciate it!
TNV |
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Mon Jul 01, 2013 9:59 am Post subject:
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A 40106 oscillator isn't voltage controlled so it can be difficult to control. You might want to consider changing to a VCO instead.
Otherwise, you could try the top octave method instead. You tune 12 40106 oscillators to your top 12 notes, and then use 12 4040 dividers to divide down for the rest of the notes. Then you use the keys as switches to toggle the specific notes into the mixer. This is what pq is currently working on:
http://electro-music.com/forum/post-386114.html#386114
And I did one as my first diy project:
http://www.jacobwatters.com/c-monster.php _________________ JacobWatters.com |
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new voodoo
Joined: May 06, 2013 Posts: 94 Location: RVA USA
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Posted: Wed Aug 28, 2013 10:06 am Post subject:
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well i did it. doesnt seem theres too much interest in the topic but if anyone wants to know how or see photos etc just pm me. |
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Wed Aug 28, 2013 10:09 am Post subject:
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I'm interested, and I am sure that others will be too. Could you post a pic and/or schem and explanation of how you did it? _________________ JacobWatters.com |
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new voodoo
Joined: May 06, 2013 Posts: 94 Location: RVA USA
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Posted: Wed Oct 02, 2013 5:59 pm Post subject:
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well, basically I just did what I thought I might.
I used a keyboard off a toy piano-type thing and it used a ribbon with 14 wires(i think it was 14 maybe less), one ground & then one for each key and I just ran the pot & joysticks to that so that the signal, after going to one trimmer, was going into all of them and then when I pressed one, it would go out the one wire, and then I attached a diferent resistor to each one with 10k difference between each resistor value. Then you could tune with the trimmer and it would basically go an octave or so. Worked really well, but it was the sorta seat-of-the-pants type of nonsense I normally come up with and not scientific or whatever at all..just asshattery that ends up, oddly enough, coming out ok.
ill post pics tommorrow morning. |
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