Casio SA-1 & PT20

[BazTraD]

Hi, I'm new to this, and have aquired 1 of each of the Casio keyboards (SA-1 & PT20).
Does anyone know how bendable these are as I'm desperate to give it a try?
I opened up the SA-1 and started touching the solder points and managed to tune into Talk Sport,
which was hilarious. I did manage to corrupt it a few times that sent it on a crazy random drum path which
was really cool, but I'm not sure how to do something purposeful that I can mess around with.
The PT20 went over my head a bit as the circuitry is pretty vast for such a wee thing.

If anyone can give me some hints or tips on what can be done, it would be greatly appreciated.

[Circuitbenders]

Try a voltage drop crash on the SA-1, they are the kings of this bend. Check the tips pages on the site for details of how to do this.

Never opened up any casio PT so can't help with that one

[djsynchro]

Heya. just joined & excited! Is there anything else that can be done to an SA-1? (I noticed 2 switches on it)

Cheers. 

[Circuitbenders]

errrr, as far as i recall on our SA-1's one switch turned on some kind of wild feedback oscillations and the other was a low pass filter or 'top cut' switch. Not entirely sure though, i'll have a look around and see if i can find any notes.

[djsynchro]

I'm just asking cuz I've never bent anything before, is it safe to poke around in it?

Don't mind finding bends myself just worried to break it.
It came in the post today, I love it! Will install the voltage drop crash tomorrow.
What's a good place to solder the pot in?
Can it be done without cutting a circuitboard track?

[Circuitbenders]

As i recall theres a jumper wire on the far right of the circuitboard (back off face down, keys towards you) that can be cut and a 1K or 470Ohm pot soldered across the gap for the voltage drop crash. I think thats where both the battery input and the external PSU input reach a common point. The Sa-1 is a difficult one to break so you should be fairly safe.

This is all from memory though so i could just be making it up 

I've heard that lazer sound on loads of things, its a brilliant noise.

[djsynchro]

Hey man, thanks a milliion!
Still didn't get round to doing it, been sampling it just in case...
Been feeding Ableton Live with SA-1 grunge all day - WOW.

[djsynchro]

been staring at the PCB till I got a headache.... still don't see it.

There are two jumpers (guess I could try cutting them can always solder them back if it's wrong.)

Also there's a diode around there as well (presumably for protecting against wrong psu polarity). That's the only place where I can see the vbattery & the PSU come together. But it's tricky some of the tracks run under the keyboard rubber contact strip.

?

[Circuitbenders]

That jumper wire just to the right of the word SPEAKER is the one i'm talking about. Cut that and wire a pot accorss the gap.

I can't remember where that image came from but its from some circuitbending site so if it belongs to someone who recognises it, let me know and i'll credit it to you.

[djsynchro]

Wow! I thought you meant that one ("far right") but wasn't sure....

I just Googled my @$$ off but no joy, finally checked back here...
This must be  good karma for helping noobs on the Ableton forum. 

Thanks a million!

[djsynchro]

Ha! It's working! 

[BazTraD]

Hey guys,

Thanks for the responses, and the good advice.
Sorry for taking so long to get back to my own thread, I got disconnected for a while there.

I did get the SA1 to do some funky random stuff by taking an open ended piece of wire from one of the solder points on the jumper you mentioned and touching an end of a resistor. I think it was one of the first resistors after the first IC. It would sound as it was crashing but then it would start a cool random drum sequence. Tha was a god laugh.
Unfortunately I think I may have wasted it now though. I'll need to see if I can fix it somehow so I can try that jumper you mentioned.
The PT20 is being used for my college project at the moment so when i've finished with it there ill see what I can do with it.
If I was able to post up an image of the PT20's circuitry would anyone be able to identify stuff on it I could mess around with? As I said before the circuitry on this is far more complicated than the SA1, which is scarily simple in comparison.
The PT20 only has 7 voices, but it seems it's more designed for using the chord acompaniment as it has a few chord keys to the left.

Anyhows I'll see if I can get a digi cam and upload an image of the circuit.
cheers

[GrooveCriminals]

Hi guys, bit late on this post but I've got the Sa-1 that Paul bent.
If it's okay with you Paul I can post a couple of pix of the inside.

[Circuitbenders]

I'd be quite interested in that picture seeing as i've managed to lose the notes for the SA-1 

Post away............

[GrooveCriminals]

Right here we go - photoshop is not one of my strong points so sorry if it's a bit basic 

This should be a photo of the chip to the right of the board (looking at Sa-1 with keyboard to the top and speaker to the left)