[sdiy] Generating a large number of CV outputs

[mskala at northcoastsynthesis.com]

On Thu, 7 Dec 2023, Danjel van Tijn / intellijel wrote:

> Let's say I wanted to generate 100 outputs with an update rate of a few kHz
> and an equivalent bit depth of 12 or 16 bits.

Which is it, 12 or 16?  You've got your work cut out for you if you really
want 16-bit absolute DC voltage precision on even one output.  The number
of outputs isn't your biggest concern when that's a serious goal.

> Now that DACs are cheaper, is it better to chain a bunch of 8- or 16-channel
> DACs? 
>
> Or would it make more sense to use an FPGA and create a giant multi-channel
> 1-Bit DAC?

Using an FPGA is going to require you to solve for yourself a lot of
problems that would be solved for you if you used ready-made DAC chips.
I wouldn't be eager to do that.  I also don't think 1-bit DACs are
well-suited to generating precise DC voltages; as I wrote at length in my
recent Web log series (https://northcoastsynthesis.com/news/dacs-and-bit-count/
et seq.), they reproduce signals, not voltages.

However, if you do put in the effort to make it work, the FPGA would
probably be cheaper.

-- 
Matthew Skala
North Coast Synthesis Ltd.