[sdiy] Hewlett-Packard Oscillator

[Travis Shire]

> The cool thing about the Hewlett-Packard oscillator is that you can
> hear it (or a clone of it) at the beginning of Frank Zappa's "Return
> of the Son of Monster Magnet", the last song on the first Mothers of
> Invention album "Freak Out" (1966).
>
> The clues are there if you listen closely... the oscillator is played
> over the 20-200 Hz range, the 200-2000 range, and the 2K-20K range.
> And each time he switches ranges, you can hear a little amplitude
> "bounce" as the feedback loop stabilizes around the incandescent
> lamp's thermal time constant.  This is a very unidentifiable
> characteristic sound.  FZ notices it, and starts using the range
> switch as a sort of percussion instrument.  And the oscillator is
> overdubbed, so you can hear two of them going at it in a sort of
> sci-fi counterpoint.
>
> While listening to this it helps to visualize FZ working the
> oscillator with both hands like a mad scientist, with his eyebrows
> going up and down.
>
>  -- Don
>

Nice sleuthin'. I don't know if I ever made it all the way through that 
"song". But I did notice the oscillator in it. He shoulda used an echoplex 
on it instead of overdubbing another osc track. That woulda gave him the 
space-sci-fi thing he was goin' for.