Cgs synth

I've got a lot of the out of stock boards back in again, though no doubt the
new and more popular boards will vanish quickly.

There are a couple of new additions - the Sawtooth frequency shifter which
makes a great wave mangler, and a basic logic board.

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Hello Ken.....and all. Sorry Ken...You must HATE me always jumping in
like this BUT!!!! This is NOT a Sawtooth FREQUENCY shifter circuit.
It's a Sawtooth PHASE shifter circuit. I can already hear people
writing in "I built the thing but the frequency doesn't change when I
sweep the voltage. What am I doing wrong?"

This circuit idea; if my memory serves me, was published in
Polyphony magazine back in the 80's.

On a side note I'm working on the "Mother of all" Analog sequencers.
CPU's, MPU's and PICS need not apply yet it'll do swing like an 808,
tied notes ala 303 Glide, random, up/down, variable note legnth and
gate time PER STEP, and will be expandable from 2X16/4X8 up to almost
any size (two 4 rack space cabinets will house an 8X16/16X8
sequencer).

I'll keep everyone posted as it progresses.

T.T.F.N......Dean

>Hello Ken.....and all. Sorry Ken...You must HATE me always jumping in
>like this BUT!!!! This is NOT a Sawtooth FREQUENCY shifter circuit.
>It's a Sawtooth PHASE shifter circuit. I can already hear people
>writing in "I built the thing but the frequency doesn't change when I
>sweep the voltage. What am I doing wrong?"

You are thinking of the waveform multiplier, which is a phase shifter. That
circuit was also in Elektor, Electronotes and ETI.

When used as specified in my article, this circuit causes the output
frequency of the primary sawtooth to shift - the result is the addition of
the frequency of the two input sawtooth waveforms. The result remains
constant too - a steady tone of the higher frequency. Yes, this circuit
requires TWO oscillators or an oscillator and an LFO both of which are
generating a sawtooth wave.

Feed it a sine or triangle wave in the second input, or "sweep the voltage"
as you suggest, and sure, you'd be back to a phase shifter of sorts. In
fact, I am puzzled that Bernie never saw the potential of his circuit for
this application. BTW, I came at my design independently, and realized the
similarity later.

I hope this clears things up.

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>