[sdiy] Sid's experience on breadboard vs. perfboard

[Aaron Lanterman]

On another note... another of my students, Sid, who did an incredibly 
complex variable slope 4-pole filter with SSM2164s, said his final 
soldered version behaved better than his breadboard version. He had lots 
of trouble with the filter freaking out at high resonances - at some 
cutoffs you'd get a nice sinewavey sort of oscillation, but at some point, 
it would go ultrasonic with a really high amplitude. You couldn't hear it, 
but you could see it on the scope, and it would eat all your headroom and 
your audio would start to disappear. He had to do a lot of tweaking 
(thanks in particular to Ken for suggesting clipping circuits) to get this 
tamed down... but it was still a problem.

Sid said his perfboard soldered version was better behaved in this regard. 
That didn't surprise me, given stray capacitances and other weirdnesses on 
the breadboard...

- Aaron

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Dr. Aaron Lanterman, Asst. Prof.
and Demetrius T. Paris Junior Prof.  Voice:  404-385-2548
College of Electri. and Comp. Eng.   Fax:    404-894-8363
Georgia Institute of Technology      E-mail: lanterma at ece.gatech.edu
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