Yamaha PSS series keyboards.

[shimshon]

it looks like the pss-120 is virtually unbendable. i think it's sample based, not FM. shorting pins on the one chip inside, i only get sounds from the various instruments and drum presets. i did find one bend point which creates a feedback loop that's inaudible when the AC adapter is plugged in, but still combines with the instrument that you play and gives it a nice overdriven sound.

the keyboard itself has some decent sounds, but generally not worth buying if you're looking for glitchy goodness.

[shimshon]

anybody have any info on the yamaha psr-77? it's been sitting in my local thrift store for quite a while now (way overpriced, i'm waiting for them to pull it off the floor, knock down the price and then use my employee discount =]) but it looks pretty big and i generally stay away from the keyboards that are bigger than 25 keys for circuit bending... so has anyone tried one out?

[computer at sea]

Hell Yeah!

I found a beat up PSS 50 in the trash pile out at my practice space today.  The case is pretty destroyed but the keyboard seems to function as stock, though I can't really get my head around it just yet.  It has an 'ad lib' button, and it plays Hey Jude. 

Super jazzed to bend it tomorrow evening.  Details to follow.

[computer at sea]

Not so much success with the PSS 50...

I've found a couple of drum mods that aren't that special and nothing else so far.  I've been poking around with a 555 oscillator and that hasn't turned up anything either.

Speaking of PSS models and 555s, here's a link to a video of a PSS-6 with a 555 osc in it. 
http://www.youtube.com/watch?v=84VozcvseG8
€There's a diagram over here:
http://www.circuitbenders.co.uk/forum/index.php/topic,799.0.html (not really sure why I didn't post that in this thread)

[pudelko]

Is there anything that can be done with the PSS 80? Ive added an audio out cable in order to connect it to a mixer so far. Is there anything else worthwhile? Something similar to the PSS 140/270?

[computer at sea]

To check if there's a dataline mod available, look for a big chip connected to a smaller one by 8 traces.

[pneaveill]

lovely indeed !
i just finished my pss140, i did the 8 switches and also a small (8 point )
patchbay, i took some of the other pins on the fm chip for that. recomendable !!
it surely adds a dimension to the already insane sounds
it will make a nice couple with my evs1

Did I miss the pics on this? Sounds way  cool and would love to see what/when/where/how of it all please. 

[nochtanseenspecht]

hmm.. thats some time ago.. no pictures i'm afraid..
but looking back in my diary  i found :

xe 562b0 pin 16 connect to pin 11 on ym 2420 will transpose keyboard down (a few octaves if i remember well)
for the sweet fm bass
certainly there's more to explore apart from the datacut mod, it will crash, but not lethal if you stay on this chips
(i hope ) yes there's more, but i dídn't wrote it down that time.. just experiment !

and here is my killer advice to turn the pss140/270 into breakbeat riddim machine :

search for an electromagnetic buzzer, like the kingstate kss1206 or simmilar.
you might find it on an old soundcard or modem.
connect this in series with an 100 ohm lin pot and a trimpot, set at +/-50 ohm , between pin 11 and pin 12

now start a rhythm and slowly tweak the pot... suprise suprise  

you betta do it before s-cat reads this and run with the patent 

[Gordonjcp]

Y'know, you could probably graft a little microcontroller in there, to act as a "proxy" for the data to the YM2413 and mangle it in really complicated ways...

[computer at sea]

Goddamn you guys!  This is why I check this site four times a day!

[pneaveill]

Y'know, you could probably graft a little microcontroller in there, to act as a "proxy" for the data to the YM2413 and mangle it in really complicated ways...

I am a total newb who has dreamed of this stuff for years and as a middle-ager, am finally getting the courage to do this.  Would appreciate all the hand holding and whatever background info you could give on this. am surrounded by a bunch of older computer cards and such, so I have plenty of things to choose from and all that.

[Gordonjcp]

Well, the YM-series chips basically talk to the host CPU over an 8-bit bus (that's the data lines you fiddle with).  There are also a couple of control lines.  What you'd do is wait until a /WR pulse (goes low to tell the YM chip we want to tell it something) and latch the data that appears from the host CPU, and then buffer it in the microcontroller.  After mangling it in some suitable way (swap the bits around, switch bits on or off, make up entirely new values) you'd write it back out to the YM2413.

[pneaveill]

hmm.. thats some time ago.. no pictures i'm afraid..
but looking back in my diary  i found :

xe 562b0 pin 16 connect to pin 11 on ym 2420 will transpose keyboard down (a few octaves if i remember well)
for the sweet fm bass
certainly there's more to explore apart from the datacut mod, it will crash, but not lethal if you stay on this chips
(i hope ) yes there's more, but i dídn't wrote it down that time.. just experiment !

and here is my killer advice to turn the pss140/270 into breakbeat riddim machine :

search for an electromagnetic buzzer, like the kingstate kss1206 or simmilar.
you might find it on an old soundcard or modem.
connect this in series with an 100 ohm lin pot and a trimpot, set at +/-50 ohm , between pin 11 and pin 12

now start a rhythm and slowly tweak the pot... suprise suprise  

you betta do it before s-cat reads this and run with the patent 

Do you by chance happen to mean a kc-1206? I just happen to have an old modem here on my desk with one on it.

[nochtanseenspecht]

could be, it s a little black can with two leggs and a small hole on top.
but i guess my mod works with any magnetic buzzer..
they're nice to use in other bending projects too, because they act funny if not used as buzzer

[davethedoobie]

pss-790 geat bends and space to install a patchbay.  possibilities are endless with this.  I get mad d=b drums but by patching to others get great analogue type gated drums.  some sinister bass sounds and well modifying the awm sounds the uniqueness is endless - i did fry my first one so tread carefully.