[sdiy] Imperfect VCO

[Czech Martin]

Well, using a state var band pass or low pass with resonance
is again filtering. If the poles are too far out, you won't hear
the ringing, in spite of the fact that it is clearly visible
on the scope.

I think high frequent wave oddities like ringing with 100kHz
or glitches with 10us width are NOT audible on a saw wave signal.
And also not on a tri wave. 
It might be different on a sine wave...

m.c.

-----Original Message-----
From: Scott Gravenhorst [mailto:music.maker at gte.net]
Sent: Donnerstag, 31. Juli 2003 17:19
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Imperfect VCO


Hmm.  What I'm thinking about is waveshaping using some distortion producing
element, such as an OTA with no diode bias and a large input signal, or a 4069
"linear" amplifier to warp the ramp.  My hope is that I can get a fairly good
amount of distortion by subtracting the original waveform.  For simplicity, I
thought I'd use an LC circuit to make some ringing from the reset transient. 
It would be nice if the ring generator could be made frequency voltage
controlled.  Can a VC state variable filter do this (make freq VC ringing)? 
These signals could then be mixed with a VC mixer.

"Michael Ruberto" <frankentron at hotmail.com> wrote:
>What about waveshaping synthesis? altering the amplitude of the wave based 
>on a transfer function which changes the wave based on the overall amplitude 
>at the input. of course it will create the same ugly curcumstance I had with 
>Aztec and it's amplitude eating but there is always a work-around.
>
>My geeky synthesis book explains this as thus "Waveshaping is the distortion 
>of the amplitude of a sound in order to produce an alteration in it's 
>waveform." as wacky as it might sound I think I could design something that 
>does this. however, PLEASE PREVENT ME FROM REINVENTING THE WHEEL. if you 
>have made this I would LOVE to know about it.
>
>I could also just cop out and buy another Miniwave from Blacet and make some 
>custom EPROMS ;-)
>
>~M
>
>
>>From: harrybissell <harrybissell at prodigy.net>
>>To: Rude 66 <r.lekx at chello.nl>
>>CC: music.maker at gte.net, synth-diy at dropmix.xs4all.nl
>>Subject: Re: [sdiy] Imperfect VCO
>>Date: Wed, 30 Jul 2003 22:25:46 -0400
>>
>>Imperfectionizer ???
>>
>>Great idea for a BBD !!!
>>
>>(except the circuitry will be pretty complex to get it only fairly 
>>imperfect)
>>
>>:^P
>>
>>H^) harry
>>
>>Rude 66 wrote:
>>
>> > >
>> > > An "Imperfectionizer"...
>> > >
>> > > Any schematics?  Ideas?
>> >
>> > some instruments react very well to lowering the amount of power. it's 
>>used
>> > in circuit bending and with he guitar pedals crowd.. this might not work 
>>on
>> > 'normal' synths or modules, but maybe on ones with a wall wart for 
>>power.
>> > it's even named as a tb303-trick to get some whacky patterns.
>> > or buy a crumar bit one, the old keyboard version. 90% of these i've 
>>seen
>> > have 'problems' with the parameters, resulting in impossible values, 
>>which
>> > creates some crazy sounds. almost empty memopry batteries will do the 
>>same
>> > with patches on a synth..
>> >
>> > ruud
>> >
>> > www.bunker-records.com/rude66
>>
>
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