[sdiy] "Living VCOs" PCB in 2009 ?

[Simon Brouwer]

Ian Fritz schreef:
> At 03:38 PM 12/9/2008, JH. wrote:
>>... it's unlikely
>>that I would have turned the reverb off, because I never make any music
>>without room simulation.
>>
>>But I got your point: Before I sell anything, I better create dry
>> samples.
>
> Thank you.  That's a great sounding demo.  Is it the beating at the end
> that the VCOs are creating?  I agree that demos should usually be done in
> a
> musical context to show off what can be accomplished.
>
> Out of curiosity, did you find something amiss with Elhardt's previous
> characterization and analysis?  I've only been able to get one sound file
> of an early Moog VCO, and it was an mp3 recorded at fairly low level.  I
> didn't hear anything special about it though.

If the character of such a VCO is determined by small amounts of jitter
and drift then it would not be apparent when listening to one VCO on its
own.

I wonder if a comparable jitter effect could be easily achieved in an
ASM-2 VCO by injecting a small noise current into one of the inputs of
U102, by connecting it via a decoupling capacitor and a large resistor to
a noise generator output.
See http://www.elby-designs.com/asm-2/vco/vco1-cco-asm2-cct.pdf

Drift could be achieved by FM modulation with a slow random signal.


-- 
Vriendelijke groet,

Simon Brouwer
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