[sdiy] Early Ensoniq Mirage DSK-8 schematics

[rsdio at audiobanshee.com]

I never owned a Mirage, but it blew my mind the way they combined dynamics-compressed 8-bit sampling with analog envelope modulation to get the most out of the limited technology.

I did buy the EPS, and have possessed three different serial numbers. Each one had a different schematic. If they published the EPS schematics, I wonder if they bothered to show every variation. Mostly they changed between 4-bit RAM and 1-bit RAM, and from 13 bits or more of memory bus, depending upon whatever RAM chips were cheapest at the time of manufacture.

The differences you're seeing in the DSK-8 seem more extensive than just the memory chips. Changing supply voltages and analog buffering (op amps) seems more like a feature change than cost-reducing generic memory.

Good luck! Let us know if you find schematics.

Brian


On Sep 9, 2016, at 8:00 AM, Rutger Vlek <rutgervlek at gmail.com> wrote:
> does anyone have schematics for the early Mirage DSK-8? I'm struggling with a sound generation problem. Basically, I'm not getting any from the voice mux (4051), before the CEMs. I swapped out the DOC chip for a 'new' one, but no luck.
> 
> I found a schematic dated 10-17-1985, but that seems different from the DSK-8 I'm looking at. It has a -8V rather than a -12V supply line. And it has double the amount of LM318 opamps for the conversion of the DOC chips DAC output (+sig and -sig), and double the LM318s for the volume feedback circuit from and to the DOC IC.