Vintage Simmons Drums (UK) Users Group

Steve Ridley skrev:
> 
> 
> 
> A few years ago I had a distortion problem with an SDS1000, and
> I came up with a useful trick for checking the system out.
> 
> I bought a 28 pin IC socket - same size as a Simmons EPROM
> and connected 8 wires from address line A0 to data line O0,
> from A1 to O1 throught to A7 to O7. Eg, pin 10 to pin 11,
> pin 9 to pin 12 etc. The wires just push into the socket.
> 
> You can get a 2764 EPROM pinout here.
> 
> http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-2.html 
> <http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-2.html>
> 
> As the SDS1 counts through the EPROM, it counts up the data
> and you get a staircase sawtooth wave sound out. Look at the
> SDS1 output on some sort of wave editor or audio oscilloscope
> software on your PC and look for a smooth regular sawtooth
> wave with 256 steps. If you get big or uneven steps, you've
> got a faulty SDS1. (My SDS1000 turned out to have a faulty
> DAC.)

Splendid tip - that goes into the "good advice-folder".
Thanks!

-- 
electronically yours, jesper
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