Uber-bender Pete Edwards of Casper Electronics shares his recipe for cooking up some tasty mods for Casio ‘SA’ series keyboards –
This is an engineered modification which works on most of the Casio SA series ( SA-1, SA-5, SA-7, SA-8 etc). There will be an Amplifier chip ( No AN8053 ) common across the SA series and a mask programmed CPU which will be made by OKI and have the part No M6387-xx where xx is the variant for the specific keyboard it is installed in, in the case of the SA-5 it is M6387-16. The different variant number accommodates different key / button layouts of the keyboard it is fitted into, the PCM sounds however remain the same. There are 5 interesting modifications that can be easily fitted:
1) Pitch Shifting
2) Power Crash
3) 5th’s Switch
4) Glitch Randomizer
5) Filter/ Feedback Adjustment
Oodles more info + sound samples available of @ Casper.