[sdiy] MOTM-800 clicks. Arg!

[Ian Fritz]

At 10:17 AM 10/16/2003, jhaible at debitel.net wrote:

>Interesting!
>Rounding the beginning ... raised cosine comes to mind. (Not that
>I'd propose using a raised cosine - just seeing the similarity
>of your description and the known advantages of the similar
>raised cosine shape.)
>I guess the perceived attack time would then be shorter than
>the actual time, with the initial rounded part being more like
>a little propagation delay than a rise time.

Yes, right.

It's perhaps interesting to look at the  electrical-mechanical analogy a 
bit here.  You cannot change the position of a body instantaneously, of 
course, but you can't change its velocity instantaneously, either.  This 
requires at least an impulse (m dv = F dt).  But in a single RC circuit, 
while the capacitor's voltage cannot change instantaneously, its current 
can.  So this means that a second order network is needed to get a proper 
physical analog.  Perhaps a starting point would be to just insert an extra 
RC between the driving signal (gate or FF) and the usual RC circuitry.

>Now what about this: Pre-processing the GATE signal with
>a fixed slew rate (linear integration), shaping this with
>a nonlinear circuit, and then using this instead of the GATE
>signal for the asymptode voltage in an ordinary RC-envelope.
>So anything longer than a few milliseconds would behave
>like a normal RC contour, and very fast attacks would be rounded.

Sure.  Maybe the nonlinear circuit could be a squarer with clipping.  Then 
only the leading edge would be affected.  The slew rate could even be variable.

Another thought would be to find a clever way to incorporate the right kind 
of response into a voltage-controlled EG.

   Ian