[sdiy] How much DMM accuracy do you need?

[David G. Dixon]

> For guys like me who are
> musically challenged (I know, a weird hobby for one with little musical
> talent/skill) it's the best (maybe only) way to tune. For this, you need a
> high count meter that will give you sub-milivolt precision and accuracy in
> the +/- 5.0000 volt range.

Not true!  If you have a reasonably accurate CV keyboard and one other
oscillator which can keep oscillating at the same frequency for more than
five minutes at a time, then that's all you need to tune.  Well, that and a
scope with at least two channels.  Eliminate the relative motion of the two
waves on the scope at two different octaves in the low frequency range
(100's of Hz), and you're tuned.  Repeat the performance in the high
frequency range (1000's of Hz) and your HF trimmed.  This may require some
iteration.  The advantage of this method is that you end up tuning to your
keyboard, which may not be generating exactly 1V/octave, but will at least
drive your oscillator in tune.

(Bring on the flames...)