Alternative to MIDI-CV

Colin Fraser colinf at easter.euro.csg.mot.com
Wed Feb 14 09:24:51 CET 1996


The DAC in the TB 303 is made up of a R-2R network, of 1% tolerance
resistors.
If you think the tuning on a 303 is stable enough then you should be happy
with a cv convertor made the same way.

You only need 7 bits to produce the full range of midi notes (128), as long
as a change of 1 at the input = 83.333 mv, you'll get 1v/oct. If you used
16bits, you could have a lookup table to provide Hz/v outputs.


peace

Cf
On Feb 13, 11:43pm, J.D. McEachin wrote:
> Subject: Re: Re[2]: Alternative to MIDI-CV
> Thinking about the best DAC to use for MIDI-CV...
>
> Why not use a 16bit R-2R ladder?  Since linearity and clock rate aren't
> as crucial w/ CVs as for audio, couldn't you get away w/ an R-2R built w/
> 10k resistor networks?  Is there some reason R-2Rs don't work w/ 16 bits?
>
> JDM
>
>-- End of excerpt from J.D. McEachin





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