Yamaha PSS series keyboards.

[Signal:Noise]

The keybaord's just getting better and better, keep on finding interesting points to add switches and stuff across, and it's no got a bright blue power on LED

[geigercounter120]

i've got a PSS-780 ready to bend.  does anyone know of what fun maybe had with this, possibly the least popular of the pss series!? 

[iqoruvuc]

Find the chip that controls the drums and there should be loads of bends.  I have never done one of these but I think most of them are a similar set up.  Two large chips side by side that control the fm, and one large chip on its own that is home to the PCM percussion.  You won't get much out the two chips side by side unless you really know what you are doing, though like in previous posts you can do the datastream mod if you know what you are looking for.  If not concentrate on that one single large chip - There are so many bends on this one chip you could do a patch bay if you like, and probably add few capacitors betwen the bends too.

[catweazle]

I've got a PSS-16 but it seems to be a "one chip wonder" only one IC inside. 
Anybody has an idea of possible bends? (except for CPU-Clock bend)

[iqoruvuc]

Hi I've got PSS-12 that I bent that wasn't fm just plain PCM.  That had just one main chip (I think).  I think it is a stereo version of the PSS-6 (which appearantly makes some good bends.  It's a curious keyboard because it looks totally crap but the sound quality is quite good.  I didn't find many bends on it though, no streams of noise just variations to some of the voices.  I imagine the Pss-16 will be similar no doubt bettet then the PSS-12.  The rubber pads at the bottom of the keyboard had turned into liquid on mine, and therefore the entite keyboard was covered in smearings of black tar when I found it - that was about the most interesting thing for this model!

[andy_wheels]

i'll dig my pss-6 out soon and see if i can give you the bend to get the random sequence. it would be interesting to see if it's repeatable.

[nochtanseenspecht]

i think to do the datastream mod with a patchbay instead of switches...
(pss 140) maybe interesting to mix up the data for even more possibilities.
Any opinions on that ?? by the way; thanks for all the nice info !

[Signal:Noise]

I'll be trying this, at the very least it'll look fucking cool. Just need to source another suitable PSS keyboard.

[andy_wheels]

hmmm, it might be interesting to try a patch bay with a pss. it has to be worth a try although i'm not sure you'll get any different bends to the switches.

[geigercounter120]

Find the chip that controls the drums and there should be loads of bends.  I have never done one of these but I think most of them are a similar set up.  Two large chips side by side that control the fm, and one large chip on its own that is home to the PCM percussion.  You won't get much out the two chips side by side unless you really know what you are doing, though like in previous posts you can do the datastream mod if you know what you are looking for.  If not concentrate on that one single large chip - There are so many bends on this one chip you could do a patch bay if you like, and probably add few capacitors betwen the bends too.

OK, i think i've found the PCM chip in my 780: it's conviniently partially-hidden beneath the 2nd, smaller circuit board.  i've gottn a few cool sounds out of it... but not much... i think this may be because one of speakers seems to be erratic at best.  do the drum sounds come from a different speaker to the keys? the speaker that's playing up is of the right hand side if yr looking down at the keyboard (in the normal. non circuit bending playing position!).  i dont know if it's a bad speaker or a bad connection, cos sometimes the speaker will let rip the odd skreech/crackle but is mostly silent...

cheers dudes!


Chris

[iqoruvuc]

Hi - I imagine the sound should come out of both speakers really, it certainly does on mine.  When I get home I will post a picture of mine with the back off.  Probably completely different circuitry but it might help.  If I can work out these mp3 sharing sites I will put up some sounds too

[andy_wheels]

i think to do the datastream mod with a patchbay instead of switches...
(pss 140) maybe interesting to mix up the data for even more possibilities.
Any opinions on that ?? by the way; thanks for all the nice info !

i was thinking about this last night (i really don't know why.... obsession?) and had a thought that a patch bay might not work very well for the data stream hack mod. the reason being that you mostly use the synth with the hack switches in the 'on' position, only turning them off to change patches and 'edit' the sounds. a patchbay would have to be set up so you had all eight of the streams connected for the majority of the time. not such a great idea. switches make more sense in this context.

[nochtanseenspecht]

Thanks for your reply, Andy
i think about what you say, i hope i get it right...
the idea of the patchbay is that i can not only put streams on and off
-wich is easyer with a switch- but also route the data to another point,
like mixing up several streams. i have no idea if it would give an interesting
result, what do you think ?
anyway, i just got my pss140 yesterday.i will first search for other bents
and think what i will do with the data mod...
unbended i found it a horrible keyboard by the way. just 3 or 4 interesting
patches. the 8 voice polyphony is nice .

[nochtanseenspecht]

yeah that's better! sick shit is coming out of the speaker. that's how i like it.
now i know what to do: i'm gonna put 8 pushbuttons (breakcontact) for
the datastream mod, and also a small patchbay, i found some shortcuts on
the fm chip also not bad. i guess there is plenty more to explore,
found also a resofilter type noise somewhere, but hard to control.
i realy start to like this keyboard !

[andy_wheels]

hehehehe, nice one 

the yamaha pss fm synths are lovely.