DIY CV Keyboard using salvaged keybed (Help?)

cds56 · Joined: Jan 13, 2011 Posts: 18 Location: Canada

The other day my Yamaha PSR-500 Died Sad

.

Sadly irreparable, its keyboard is in fine condition.
So I decided to spare it in case it might be useful to give me a 1V/oct keyboard...

So would it be possible to use this keybed with with one of ray's designs, to interface with my Soundlab?

Another thought is I could buy the OEM version of the Doepfer A-100 Keyboard and connect it to the keybed (saving me 250 euros!)
Pics coming, also other info can be provided if needded..

Feifer · Joined: May 16, 2012 Posts: 54 Location: San Diego

It's possible but in my opinion not ideal. That is if I understand it correctly to turn it into a single buss ie resistor chain keyboard. Those kinds of keyboards have a type of conductive plastic contact switches under the keys that have a resistance of around maybe 250R when closed, which if (big if) they are all uniform you won't notice as long as you only hit one key at a time. If you happen to hit two at a time you drop too much voltage in the switches and get a lower, sour note. I think this is why Ray recommends using reed switches and magnets. So you might want to look into that (I have not). I've found there are easier ways to control a synth. Like a cheap, used midi keyboard and a http://www.midimplant.com/ midi to cv. Just my 2 cents though. Hope that helps.

cds56 · Joined: Jan 13, 2011 Posts: 18 Location: Canada

Thanks for the reply, I have seen the midi implant before, but that was when I had no idea what it was other than some Midi > CV converter with no jacks :O

Now I guess to use it I'd have to wire it into my soundlab somehow.. ( the issue)... and I already have a midi keyboard, so that would be an easy solution.

I would need a Midi jack right?

dylar · Joined: Apr 25, 2011 Posts: 55 Location: iowa

I built one out of an old Casio and it works great--perfect over four octaves. I created a "how to" thread on here somewhere. As previous poster said, however, if you hit two keys at once you get a sour note. If I had the cash I'd do midi-->CV, but I didn't have it at the time and had already built Ray's mini keyboard controller so all I needed for parts was a handful of resistors.

analog_backlash · Posted: Mon Sep 10, 2012 6:10 pm Post subject:

Hi,

I built a 'flightcase synth' based mainly on Ray Wilson designs, using an old 49-key organ keyboard. What I did was to fit some small PCBs under the keyboard, which contained the resistor chain and a series of SPST tactile switches, positioned so that the keys depressed the tactile switches. It was a bit fiddly, but it worked fine. Depending on the keyboard design, you may need to add some glued on flat pieces of plastic (etc), in order to engage with the switches. I (thankfully) didn't need to do this. I have attached a diagram of my PCB designs (not done on CAD, so they're only rough). They show the top view (component placement), foil view and how they are all wired together.

It's one way of doing it anyway,

Gary

Tactile Switch Keyboard.jpeg

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