[sdiy] uLaw DACs in the modern era?

[Tom Wiltshire]

Hi All,

Over the last couple of days I’ve been studying early drum machines, mostly the Linn LM-1 and the Oberheim DMX.

Both of these machines use 8-bit memory, but manage a 12-bit dynamic range by using a u-Law coding and outputting samples via the AM6070 u-Law DAC. Datasheet here if you’re interested:

http://synfo.nl/datasheets/AM6070.pdf

Does anything like this exist any longer? It seems to me that the unusual DAC response is big part of the “thump” of these early machines, since it has considerable distortion, but manages to spread it to areas where it’s perceptually less noticeable (so higher level signals have less detail than lower level signals).
Alternatively, would it be possible to build such a device? The combination of a 4-bit value plus some gains and offsets doesn’t seem impossible to manage, but I’d be interested to hear people’s ideas for how you’d do it.

Thanks,
Tom

==================
       Electric Druid
Synth & Stompbox DIY
==================