Circuit bending my Yamaha PSS-280.

Nixot · November 17, 2010, 05:12:46 PM

Hey everyone.
I am in possession of a Yamaha PSS-280 that I plan on circuit bending. I've already made a few test bends and have found 21 bend points, and am therefore going to create a patch bay.
The sounds I have found are awesomely varied - dirty distortion, insane drum glitches, dark moody tones, wacky chirpy sounds and a lot more.

I'm going to be updating this thread with details about what I have done and finally an audio demo. I just want to say, before I begin, have any of you circuit bent one of these before, or a PSS-290 (they're the same)? I'd like to get as many bend points as possible to create a vast array of sounds. If you want, I'll share mine as well.

Updates will be delivered as they occur.

electoyd · November 19, 2010, 12:00:54 PM

hey i've done one of these bad boys it is a whacky item indeed, a much neglected bending target i feel. I would take a photo but i think this bent keyboard is up in my attic, if i get the chance i will get up there open it up and post a photo. I thought you may be able to do the fm chip mod on it but the circuit board is multi layer and looked impossible to trace.

Nixot · November 19, 2010, 02:09:00 PM

Cool, if you can get it from the attic and take a look that would be awesome.

Nixot · December 04, 2010, 11:26:11 PM

The patch bay has been soldered with wires! Now to solder the other ends of the wires to the connector!

electoyd · January 10, 2011, 12:10:36 PM

hey Nixot

against all odds, i dragged my bent pss280 out of the attic. Now i just have to open the fecker up and get some details for you cant guarantee it will be that soon, but it is within easy reach now so that must be progress.

cheers

ian

electoyd · January 13, 2011, 10:28:21 PM

Nixot

here's the points i used, hope they are of some use

XG214BO (64 pin chip)
pin 51,52,53,54,56,57 --> each other and the 2 rows of metal jumpers to the side of it

AN90B22 (18pin chip)
Pin 18

YM7116 (18pin chip)
Pin 9,11,12,13,14,15,16,17,18

as far as i remember they can all be mixed up, though i dont think the metal straps can be mixed with each other you would need to try it has been a long time since i did this.

warning this information may mysteriously vanish! only jokin

Nixot · January 14, 2011, 10:27:15 PM

Thanks a lot for that info. I'll try and find the sheet that had all the pins I noted down on it (it's "mysteriously" disappeared, meaning I will need to tear my room apart looking for it). Then I'll compare. I noticed you found a bend point on the AN90822 chip, which I thought was unbendable. I'll certainly have a look at that. Thanks again!

electoyd · January 17, 2011, 10:25:18 AM

it's prob just a ground pin on the AN chip or summat its been so long since i did it and have no notes i just opened it up. I like the crazy sound of this machine quite blippy and glitchy, felt like re-doing it actually sure i could make a much better job of it now and its all soldered with the dreaded lead free solder so i expect it will fall apart and need re done at some point anyway