[sdiy] harmonic generator

[media.nai at rcn.com]

>Can anyone recommend a harmonic generator circuit - I need about the
>first 10 harmonics of a given fundamental.

I've been trying to do this for awhile.  If anyone has schematics for the
Buchla 185/285 -- you let me know!!  Serge had one in their catalog, but I
do not know if they ever made one.

>1. Phase Lock Loops

I tried that.  You need to run the input through comparator, then through a
pulse divider into the PLL, then put another divider in the feedback loop
of the PLL, then shape it into sine.  You need one of these circuits for
each harmonic, although you can use logic to change the divider values.
Besides shaping the sine, the trouble is the lag of the PLL, which is quite
audible.

>2. Walsh function to sine

What's a Walsh function??

>3. Divider chains
>4. Look up tables
>5. Rate multipliers

How does a rate multiplier work??

>you could try using Jürgen Haible's wave multiplier for the x3,x5 and x7
>ones or the timbre section in the Buchla 208. the Buchla distorts the
>input at a variety of levels and then combines it back together to get a
>multiplied frequency. In the actual Buchla 208 it comes back a kind of
>odd shape, but it was using a sine as the input wave. With a triangle,
>you may be able to tweak it into submission;) You wouldn't need all the
>stages for all the multipliers either. Maybe you could try tweaking the
>break points. This could get ugly.

I guess I should look up JH's circuit.  I'm not familiar with the Buchla
208.  Is there a schematic on the web??

>the even numbers are a simple matter of full wave rectification. Then
>you need 10 tri to sine converters.

Wouldn't full wave rectification simply result in octaves??

>What you'd need is the electronic analog of a big
>gearbox that has output shafts at 1, 2, 3, 4, etc
>times the input RPMs...

LOL!!  Is there a transmission-diy list?? :)