Yamaha PSS series keyboards.

nochtanseenspecht · August 28, 2008, 08:50:24 PM

NewBender · September 02, 2008, 09:41:09 PM

I just bent the PSS-20 as my first bend

There wasnt a lot of bending possibilities on it (as far as i could find anyway) but i did find one really interesting one, because the keyboard has an 'auto arpeggio' feature where you press any bkey and it will do an arpeggio around that key. I found a bend that speeds up whatever is being played so that when the auto arpeggio feature is on you basicly have a really interesting oscillator sound that moves up and down in pitch as you move up and down the keys. This sound can be altered loads by simply changing the speed of the arpeggio, the type of drum rhythm, and 'voice' selected.

The only other worthwhile bend i could find was a kind of distortion that makes a lot of the voices sound like a distorted trumpet.

Those sounds are really interesting but as i say they are the only worthwhile bends i could find on it.

zoomtheline · September 03, 2008, 01:32:44 PM

Wow! thanks very much nochtanseenspecht

I have been shockingly busy at work this week and gutted I have not had time to open her up again, But I will asap and let you know how it goes.

Thanks again!

nochtanseenspecht · September 03, 2008, 10:48:55 PM

you're welcome

hope you find some fresh bends

justindeloop · September 06, 2008, 07:01:40 PM

just a quick warning - i managed to fry my pss-140 within like an hour of opening it up - i guess theyre a lot more delicate than they look.. (or maybe im just unlucky!) ..so watch out our if youre prodding around the 'speaker side' of the board! it seems its probably safest to stick to the documented (data stream) mods unless you have a few spare or like living dangerously

computer at sea · September 06, 2008, 08:19:17 PM

Did you try to discharge all the capacitors? That may bring it back.

justindeloop · September 06, 2008, 09:00:27 PM

Quote from: computer at sea on September 06, 2008, 08:19:17 PM
Did you try to discharge all the capacitors? That may bring it back.

good suggestion, i didnt think of trying that...

..but still no luck unfortunately.

have you had that happen to you with this particular keyboard before then?

computer at sea · September 07, 2008, 03:54:23 PM

Not with a 140, but I've had other things come back to life that way.

Signal:Noise · September 07, 2008, 05:56:30 PM

Quote from: justindeloop on September 06, 2008, 07:01:40 PM
just a quick warning - i managed to fry my pss-140 within like an hour of opening it up - i guess theyre a lot more delicate than they look.. (or maybe im just unlucky!) ..so watch out our if youre prodding around the 'speaker side' of the board! it seems its probably safest to stick to the documented (data stream) mods unless you have a few spare or like living dangerously

I've done similar to the last two I tried to modify, though I didn't outright kill them, I fucked up the patches...drums would sounded fine, but the patches we very quite and through a lot of white noise.

hoffy · September 09, 2008, 01:31:19 PM

Ugh, i'm just about to mod my 140, thanks for the heads up

I don't intend to do anything fancy with it all (ie: I'm not going to probe for bends, unless i find another one

), just the data cut mod... which i'm already confused as hell about.

Thanks for the heads up

nochtanseenspecht · September 09, 2008, 08:45:38 PM

yeah, the datacut mod ! and you can make other shortcuts on the fm chip of the pss140 savely as well

Gleix · September 14, 2008, 10:00:46 AM

I picked up a PSS-200 today for cheap at a yard sale (I think UK members call it a car boot sale? I'm in the US)

I've found some really nice distortion bends on it and drum triggers, but I can't seem to find much else. If I was to locate the FM chip (Assuming the data cut method would work with this) I was considering the data cutting method but, (pardon noobish question) I'm a bit unsure on exactly how to do it. Should I just use a small blade and slice across the circuit board in the one area I'm supposed/add switches to correct spots to or is there more to it? only part I'm unsure about is the slicing.

Thanks in advance for any help :]

Circuitbenders · September 14, 2008, 11:22:20 AM

if you can find the datasheet for the FM chip you'll see 8 pins labelled D0-D7 or D1-D8. These are the 8 data line pins which wil connect to the main CPU via circuitboard tracks. You should just cut these 8 board trackss with a sharp knife and i usually prize up and roll back some of the copper track just to make sure of the cut.

Install switches accross the tracks you've cut so you can turn them on of off and there you have it.

Jing · October 08, 2008, 11:25:43 AM

Hi. I have a PSS-140 and PSS-270 on the way from EBAY. In the meantime I have been researching any info I can find on these. I plan on doing the data cut mod to them. I have read that the results when, for example, patch 1 is chosen, a data line is switched off, then patch 2 is chosen, will give you random results. Then i read this on the tablehooter site. http://weltenschule.de/TableHooters/WarrantyVoidFAQ.htm states in the "build your own FM synthesizer" section, "Solder at the soundchip side a pull-up resistor (each about 22 kOhm) to each data line and connect their ends to a single alternating switch ("0/1 switch") that pulls the resistors against GND or against +Vs. To use the instrument as normal, switch all DIP switches "on". (The pull-up resistors are necessary because the open data input lines would otherwise pickup EM noise and thus cause random results." Has anyone tried this, and also could someone dumb this down for me. I find it unclear exactly where/how to place the resistors.

hoffy · October 21, 2008, 11:55:29 AM

I've got a question about the pss-270 too;

I attempted the data cut mod, and i fucked it up. I soldered and re-soldered and did it all over again. I'm assuming now every pin on the CPU / Synthesizer chip is soldered to either another pin or somewhere else it shouldn't be.

The machine is impossible to use in "normal" operation.

I don't need to turn the switches on or off to get strange patches. i get a paranoid mess each and every time.

When in drum pattern mode, my machine spits a never ending stream of noise, static, giltches, and the occasional melody. At times, it's a drone machine. Other times it's silent. Other times still, the pss-270 will produce wonderful and strange melodies.

The best bit is, that in demonstration mode, it changes to a new random patch at the start of every measure. So if you find a sound you like, you press "stop", and the last patch in memory is still there for you to use/abuse/sample.

So my question is this: Does anyone know what the fuck i did? It's amazing, and i'd like to try do it again.

PS: Jing; I don't know what any of that tablehooters stuff means but if picking up "EM noise" and thus causing "random results" is what my machine is doing, i highly recommend it.