tracking has a long tradition on homecomputers such as the atari st and is still one of the most fun and alert ways of composing electronic music today. during the last twenty years many innovative musicians and programmers have pushed the ym chip to the max by writing incredible drivers and tons of impressive chiptunes. nowadays, the innovation is still alive and a few active composer enjoy the cream of improved tracker programs available. after all, sometimes we dream about things which are not available, even if these are only little things. dreaming is one, the other is to go straight ahead and start writing down the idea...

 

the idea:

since i'm not a programer, nor an engineer, but a captain of the soldering iron, i decided to go the hardware way to push my favourite soundchip a little bit. the idea is to build an effective tool that lets us intuitively play with the music after or during composing process. imagine the atari with its tracker and the built in ym chip as a cat we pet, untill it starts to purr ;]
ymixer is a realy basic project that can be built by any tinkerer. anyway, it's also a perfect live tool in association with stj.
actually i have no idea where this project is going to end... a sYMthesizer? who knows ;] as usual when you start working on a basic thing, you get into it more and more. further details and some schematics will be posted here sooner or later.

 

ymixer features:

- ym channel mixer [see name]
- individual mute switch
- panning [stereo pot for all channels]
- voltage controlled filtering [lp, bp, hp]
- analog switch selector for ym to vcf mode
- sound effect circuit [also used for control voltage]

 

pictures:


workbench

 


circuits

 


mega st

 


prototype

 
modules:

- mixer
- vcf
- select/mute
- sound effects

 
state:

prototype works good
prototype ok, improvement possible
prototype works fine so far
lazy mode, still not sure about that

example mp3:

first prototype [with all 3 ym channels in action]
recent prototype [with only 1 ym channel in action*]

* = during fiddle around, i killed one ym chip :.[ rest in peace.
ymixer sources & inspiration:

ym2149.pdf [the ym2149 datasheet]
modular synth [ken stone's d.i.y. site]
music from outer space [another loyely d.i.y. site]

 
other links:

stj [coolest dj software on earth by gwem]
ym rockerz [ym2149 chipmusicians united]
tracking.atari.org [news about atari tracking]