[sdiy] harmonic generator

[media.nai at rcn.com]

>When we say 2nd, 4th, 8th, etc. we are talking about harmonics, not musical
>intervals.
>Ex: fundamental = 100 hz
>2nd harmonic = 2x frequency, or 1 octave up (200 hz)
>4th harmonic = 4x frequency, or two octaves up (400 hz)
>8th harmonic = 8x frequency, or 3 octaves up (800 hz)

Doh!!!

So I guess I've been working on a "musical interval generator" by accident.

>My understanding is that a full-wave rectified (absolute value) sine wave
>contains an infinite even harmonic series. A square wave contains an
>infinite odd harmonic series.

Is that true??

>Rate multipliers one of the coolest logic circuits around. Look at 7497 or
>74167. I think these were only made by Texas Instruments. There are a
>>couple of CMOS rate multipliers as well. Think of a logic block with a
>>clock input, a binary select the rate out and output at the rate. For
>>74167; 1 clock in 10, 2 clocks in 10, 3 clocks in 10. The down side? The
>>clock rate output is not evenly spaced. It must be divided down to reduce
>>pulse "jitter".

Wouldn't that be a rate divider (in other words a counter)??  That would
multiply the frequency when placed in the feedback path of a PLL.

>But the 4046 and friens are not good oscillators if you aim for
>sine-waves.

You're right, they aren't, but at least they are fairly inexpensive.   Is
there a good PLL or V/F converter that produces a sine??

>285 is the Frequencey shifter/ ring modulator.  I think you want the
>148. As far as I know, there was no 200 series version.

You are correct.  I typed the wrong number.  Apparently, the 248 is the
Multiple Arbitrary Function Generator.

The Buchla 148 is described on their website as having a voltage input (ie.
it contained a VCO).  As far I can remember, the "harmonic generator"
described in the Serge catalog used a frequency input (which is why I
thought it might have been based on a PLL).  I don't know if the Serge
module was ever actually made, however I do know it was in their catalog,
because I saw it before I ever knew the Buchla module existed.



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