Yamaha PSS series keyboards.

[nochtanseenspecht]

cool ! never saw it before...

[MagpieIndustries]

I can report success with a PSS-170, there are 5 lines going between the two main chips that can be shorted out and produce a range of new squeaks and bleeps. I havn't tried cutting these lines yet, but I suspect it could be done, and wire them to each other. No pitch bend, and I've yet to find a bend that effect the drums.

[nochtanseenspecht]

i bent a pss 780 last weekend : (simmilar to pss680)
with the pcm drums/ rhythms some freaky things can be done,
loads of distortions /overdrives on the FM sounds
strange enough i didn't seem to get real access to the FM chip... it crashed everytime
at least i found a kind of random arpergiator wich mixes up the fm tones....

but a bit disapointing after all.
expected a bit more from this former yamaha flagship...
it is a nice keyboard anyway ; midi, synthparameters witch can be changed, rhythm pads
see if i can get rid of it 

for me, the pss390 remains the best from this series

[iqoruvuc]

How did you get distortions overdrives on the fm sounds?  I have only managed to bend the rhythm chip on this range of keyboards.  The random arpegiator sounds good too.   I have heard the pss-790/795 is quite good fun all 'AWM' synthesis so loads of randomness appearantly.  They tend to go for a little bit too much on eBay though 

[nochtanseenspecht]

hmm, i don't remember exactly...didn't connect the distortions after all...
but i think it was a shortcut between the points where the keyboard flatcable comes in the main
circuitboard and one of the opamps...  at least 5 differend distortions orso. some quite nice in fact,
a kind of flanging distortions. yeah i like the pcm rhythm chip on this one. pitty i wasn't able to
modulate the fm with the rhythms, like with the older yamaha fm keyboards, but maybe
i'm just not smart enough (or lucky)
or , could we say that later generation yamaha fm chips are not so bendable  ? (dataprocessing
and fm together in the same chip ?)

[AttDestroyers]

Sorry I'm dumb, but does anyone know which of these 2 chips has the data lines that go to the big chip? yellow or red?

http://i96.photobucket.com/albums/l169/justindeininger/Whichchip.jpg

thanks

[Griffin]

Probably the yellow, as it is right next to the big chip. Turn it over and follow the lines out of the yellow chip, they should run right into the big chip

[AttDestroyers]

Aight. Thanks. I'll start cuttin

[Griffin]

Voltage Drop for the PSS-270 - how is this setup and what items do I need? Gonna start on this bad boy this weekend as I've put it off for too long.

[noisefactory]

I am close to completing a bend of a PSS 270. I hav been following the tutorial by Kevin Rees at http://www.circuit-bent.net/pss-270-tutorial.html and im stuck, can anyone help me? Iv tried contacting him but iv had no reply so far. He explains how the green dots on the diagram provided indicate the four solder points that should be de-soldered. He goes on to connect a wire to each of these point but then I am confused as to where these wires go. He says to 'put wires through to make the connections for pin 17 and 18'. Does that mean to solder the other ends of the wires to pins 17 & 18 on the chip? This would mean that three wires would be soldered to pin 17 & 18 of the chip. Is this right? It may seem like a stupid question but its pickling my head - help!

Nick

[earthstandstill]

Heh, new poster to new poster...

Look at the next photo below. He has removed the 2 jumpers (bare wires) and used the now empty holes to attach the wires for the switches. The 2 brown wires to the switch for pin 18, 2 green for pin 17. It's just easier than soldering to the IC, plus, no traces to cut through.

[noisefactory]

So does that mean i solder the 2 brown wires to the same switch as the wires for pin 18 (meaning that 4 wires will be soldered to that one switch)? and the same for the green wires but using the switch for pin 17?

[earthstandstill]

No, not 4 wires on one switch. The browns are for one switch, and the greens are for one switch. The traces from the jumper holes connect to the IC pins.

Or, just solder your wires to the IC pins (blue dots and red dots), and cut the jumpers.

[noisefactory]

So how many switches will i end up with all together? From the pic provided it appears that it should be 8, but i have 10 pairs of wires which would obviously result in 10 switches. This is waht could be confusing me. Iv got this far under the impression that i will end up with 8 switches, only to find now that i should have 10. Is this right? 10 or 8? Thanks.

[earthstandstill]

Eight. The far right two red dots on top ARE the same connection as the top two green dots. The two far right blue dots ARE the same connection as the bottom two green dots. It's just an easier solder job to pull the jumpers and use the green dot pads.