[sdiy] Has anyone built a voice pitch tracker?

[Ingo Debus]

Buck Buchanan wrote:
> Ah, the joys of pitch extraction.  I've had exactly the same issue (I 
> think) when trying to extract pitch from an electric guitar signal.

I have built a pitch to MIDI converter for my flute. At the German DIY 
meeting in Bad Berka, Nils Pipenbrinck tried it with an electric 
guitar. The result was surprisingly good, almost better than with flute.

It's nothing fancy, on the analog side a preamp, a low-pass filter (fc 
about the highest frequency a flute can produce) and a 7413 schmitt 
trigger. On the digital side there's a processor with timer in capture 
mode. On every active transition of the schmitt trigger, the timer 
count is copied into the capture register. The processor calculates 
MIDI note and pitch bend information from this.

Ingo