[sdiy] Keyboards good for scrap / repurposing?

sleepy_dog at gmx.de sleepy_dog at gmx.de
Mon Feb 19 00:03:36 CET 2018

Hey Tom,

 > old electronic organs

yes, those organs, but, they are so damn bulky & heavy!
Alas, if someone gives it away for (almost) free, they would be very 
angry if I came, took the keyboard, and left. The transport of those 
things would make it expensive again, nevermind getting it up here...
Hmmmm, then again, if I pick one up when it's good weather, I could 
dismantle it in front of the seller's house, probably irritating some 
passersby, and put it into my (not so huge) car piece-wise.
Would you have an idea as to how quickly those behemoths are usually 
disassembled? How much air is in there, or are they really packed full?

While this probably does sound like a lot of effort to get 2 small 
keyboards, I have to say, I am rather curious about taking apart one of 
those monsters, I have never directly seen one inside. So it would 
actually be fun by itself :D  (If only I had the room, I might even keep 
the "enclosure" (more like furniture) and put different electronics 

- Steve

Tom Wiltshire wrote:
> Just don’t try and use the keyboard from a dead Korg Polysix or Poly61! They use hopeless rubber dome contacts that really aren’t reliable. Probably like those dodgy Pro-one keyboards already mentioned - I wouldn’t know, my Pro-One has the J-wire keyboard - a bit clunky but always works.
> Personally, unless you want velocity sensitivity, the cheapest source of reliable full-size keyboards is old electronic organs. They often finish up costing £20/€20 or less for a couple of decent 49 key keyboards, even if there’s nothing else worth salvaging. The nasty transistor-based Hammonds from the 1970s are basically worthless, but nonetheless have very well built keyboards with multiple contact busses with some non-corroding wire on the contacting surface.
> HTH,
> Tom
> ==================
>         Electric Druid
> Synth & Stompbox DIY
> ==================
>> On 18 Feb 2018, at 13:12, sleepy_dog at gmx.de wrote:
>> Hey, thanks for the details!
>> Yes, I'd use my own firmware.
>> rsdio at audiobanshee.com wrote:
>>> Most keybeds have a local PCB with the raw electronics for a scanning matrix. That means it will be wired for Rows and Columns, each of a specific bit width, and diodes to prevent ghosting. I assume you’ll want support for Velocity, which simply means twice as many switches (although there are some clever ways to share either Row or Column between the two switches for each key). I’ve never seen a keybed with sound generating electronics on the same board, so you most likely won’t have to rip out anything that you won’t use.
>>> My question is whether your projects will have a CPU, and whether you’ll be programming the firmware. If yes to both, then it should be fairly easy to allocate the appropriate GPIO pins to the Rows and Columns from the keybed and then pick a scan rate and allocate some bits to key state so you know when to generate Note On or Note Off messages, with Timers or something to measure the switch timing for Velocity.
>>> The only other challenge might be finding a connector that matches the connector from the keys. I’m assuming that you’ll make a custom PCB for your project that will include everything but the circuits on the keybed. If that’s true then just plan for a matching connector on your board.
>>> If you’re not using a CPU or writing your own firmware, then maybe something like the MIDIbox or some other MIDI kit could be hacked to connect to the keyboard.
>>> Brian Willoughby
>>> Sound Consulting
>>> p.s. There are the old, non-Velocity designs with J-wire mechanisms. Those could possibly be adapted, but they might be disappointing compared to the more modern standard switch-based keyboards.
>>> On Feb 17, 2018, at 7:28 AM, sleepy_dog at gmx.de wrote:
>>>> Are there some known models of keyboards (MIDI or with sound engine, no matter) which would make sense to look for in "broken" condition to get them cheap, to use the keys for DIY synths? I.e., they should lend themselves well to ripping out the keybed/keys without damaging the needed parts. I guess you'd always have to build new switches PCBs, as such keyboards would have everything (I dont' need) on one PCB, right? (I never opened such a thing)
>>>> I am interested in both, quality, and "usable enough to have some fun" types for different purposes ;-) And it's not restricted to short keybords generally, just right now in particular I'm after a cheap 37..43 key one.
>>>> - Steve
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