[sdiy] "Living VCOs" PCB in 2009 ?

[JH.]

>Is it the beating at the end that the VCOs are creating?

I think that demo is way too short to really demonstrate anything, except 
maybe a quick first impression.

> Out of curiosity, did you find something amiss with Elhardt's previous
> characterization and analysis?

Oh, I remember that heated discussion well that we all had on a forum called 
the gas station, which then swapped over to the analogue heaven mailing 
list. I remember it well because I defended the merits of very precise VCOs.

I did not go into the measurement stuff myself, and only followed Ken's 
measurements loosely. Because for me, it's obvious - simply from theory! - 
that you can emulate the behaviour of *any* real VCO, using an ideal VCO 
plus amplitude modulation and frequency (or phase) modulation. It's just a 
matter of choosing the right modulation signal. (Which, admittedly, may 
proove not trivial.)
I also remember I defended Ken against a personal attack from someone who 
tried to ridicule him for his measurements.
I noticed that this has caused the impression that I understood what he has 
measured.

In retrospect, all these discussions feel extremely painful. They have even 
been painful then, for me. (Even though I admit, and regret, that I've dealt 
out some fire myself.) It's hard to understand why such a simple matter as a 
VCO can polarize people so much, divide them into groups that oppose each 
other, and reduces the individual thoughts and contributions and theories of 
individuals to something that is apparently shared, and verified, by 
everyone in one such group.

The really funny thing is that I had just finished my JH-5 when these 
discussions took place. I liked what I had, like a child that is content 
with his new toy, because it had a certain character I'd been looking for, 
without being a copy of the instruments that inspired me. That gave me some 
confidence in my theories _without_ following the various measurement 
efforts too closely. I've never been the scientific type, really. I'm 
analyzing classic circuits up to the point where it gives me some 
inspiration what to try, I throw away my failed attempts, and I'm happy when 
something sounds the way I like it. Then I'm too bored to measure and 
analyze what I've accomplished, and - as it actually happened - I even 
displace my design documents for a few years and forget the implementation 
details. That's why I'm so happy I found them again. :)

JH.