Pitch/Voltage converter board ready at EFM

[harrybissell at prodigy.net]

If you're an experienced hacker it might be worth a try... as far as "off the shelf"... no.

The problems I noted were these (I tried a simple plug in a mic test...)

1) There is no input filtering, and the human voice usually has many harmonics. If the fundamental frequency
isn't reasonably pure a garbled output will result.

2) When a note decays it takes several cycles for it to stop. If these drift in frequency, or if the last two detected cycles get chopped up, the sample hold will latch the wrong value.

3) Higher notes have a greater chance of mistracking for reason #2. If you consider that the voice stops in (oh...) 5mS regardless of pitch... then a 200Hz input would be gone within 1 cycle, and the right value would still be latched. But at 1KHz 5 cycles would occur, and the chances of latching bad data would increase.

There is a latch input that can be driven by a positive signal... you could use a footswitch, or output from an envelope follower to latch the sample/hold before the decay of the note. Then with careful singing it would work...

I want to do vocal tracking also. It will need additional circuitry. Its not as easy as Guitar which will only need a little processing... because the vocal note could get louder at any time (guitar always gets quieter on the average...) I made this board with the intention of have a reliable module to experiment with. The parts that are sure NOT to change are there, the squaring circuits, the ramp, sample hold, and antilog converter. If you experiment you MUST have these functions... and the "Ramp" type P/V converter is always faster than the "tachometer" type.

H^)

 


 ---- On Feb 25 fleischwolf <hannes.langeder at ufg.ac.at> wrote: 
> does it make sense to go in with vocal sound ?
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