Lin detune,MS20 Core,Polysix/Trident

[Martin Czech]

In other words, an exponential VOLTAGE source (multiplying some reference
current at the same time) is recopmmended that will feed into a V/I
converter (servo loop precision source), before that some voltage can
be added or subtracted?

The initial offset voltage of components should not matter then, however
offset drift should be avoided.

btw. why not use a bipolar V/I converter (bipolar means +- current here)
in order to have a triangle oscillator (if your looking for a tri)?

m.c.

:::X-Envelope-Sender-Is: Juergen.Haible at nbgm.siemens.de (at relayer 
lizzard.sbs.de)
:::From: Haible Juergen <Juergen.Haible at nbgm.siemens.de>
:::To: Tony Allgood <oakley at techrepairs.freeserve.co.uk>, Synth DIY 
<synth-diy at node12b53.a2000.nl>
:::Subject: RE: Lin detune,MS20 Core,Polysix/Trident
:::Date: Thu, 19 Oct 2000 12:11:33 +0200
:::
:::	>So this effect can be done with a common expo generator with a
:::voltage
:::	>output driving the linear modulation inputs of normal VCOs?
:::
:::Exactly.
:::Keep in mind that the offset voltage of "vintage workhorse" opamps like
:::LM1458, TL072 or LF353 is too hight to use them untrimmed (too much
:::"lin detune" so to speak) - which I suppose is why most manufacturers
:::turned to current output expo converters driving the CCO core directly.
:::Korg used cheap opamps and trimmed them, I suggest using (nowadays
:::cheap also) precision opamps like the OP-07.
:::
:::JH.
:::