[sdiy] Bergfotron Re: Voltage Controlled Waveshape

[Cynthia Webster]

Just about my favorite VC Waveshape Oscillator combination is
Roman Sowa's Bergfotron Complex Oscillator

It doesn't seem to get any better than this!

http://hem.bredband.net/bersyn/VCO/vco_complex.htm

Unbelievable design!


The actual Wave Tweeking section is here

http://hem.bredband.net/bersyn/VCO/VCO%20complex%20waveshapers.gif

When I need inspiration go to Roman's site for another look

Thanks Roman!

Cynthia






on 8/2/03 8:35 PM, John Loffink at jloffink at austin.rr.com wrote:

>> right, but Don's are simple crossfades between 2 things, or on the 259
>> there are several CV ins to control several parameters, HOWEVER, what
> I
>> am refering to is sweeping accross several more or less unrelated
> things
>> with one voltage. That can be done with the interpolating scanner, by
>> putting whatever signals into the inputs.... however in this case it
> is
>> all waves from the same VCO that it's hardwired to.
> 
> I believe Wavemakers was the first to interpolate between VCO waveforms,
> in the 652 Dual Voice Subsystem:
> http://www.wavemakers-synth.com/652pg1.html, in 1980. In Wavemakers
> parlance this was a "lap circuit," short for overlap, much like the J.
> Haible scanner circuit.  This was used earlier in the Wavemakers Triple
> Bandpass Filter: http://www.wavemakers-synth.com/308pg1.html, mid 1970s
> time period.
> 
>> My guess, and it is only a guess, is that the Serge NTO was an attempt
>> to have the possibilties of the Buchla 258 plus something more in it's
>> waveshaper. That's why they have the sine between the saw and square.
>> Then you can set it up to sweep from sine to either, so it can be set
> up
>> as either of the 2 oscillators in a Buchla 258. Which had already
> proven
>> to be a valuable resource. You'd have to be really careful with the
>> voltage so you don't "oversweep " though.
> 
> Just to be clear, the Serge NTO does not use a scanner type circuit,
> rather the waveform is morphed through waveshaping to approximate the
> sine, square, saw and pulse waves.
> 
> John Loffink
> jloffink at austin.rr.com
> 
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com/
> 
> The Wavemakers Modular and Integrated Synthesizer Web Site
> http://www.wavemakers-synth.com/
> 
> 
> 
>