[sdiy] synth and flute, was: New here

[Ingo Debus]

Hi Thomas,

welcome to the list.

Am Dienstag, 27.01.04 um 16:37 Uhr schrieb Thomas Dunker:

>  Personally I hope to come up with ways to play my flute through some 
> of
> the synth and make some interesting spaced out sounds that way. I 
> figure
> I'll be needing some kind of envelope follower, audio input to 
> gate/trig,
> waveform clipper etc. I figure a flute is well suited for "synthing 
> up", since
> it's "monophonic" anyway. If anyone has experimented with something 
> like
> this, I'd like to get in touch with them.
>

I play the flute too, and I built a pitch/volume-to-MIDI converter for 
it. Pitch recognition works ok-ish as long as no other sound sources 
are around (i.e. it's impossible to use that thing in a live band). The 
pitch recognition is pretty much staightforward: preamp, low pass 
filter, Schmitt-trigger, period measurement done by the timer of a 
microcontroller. The volume recognition is done by an envelope follower 
(full wave rectifier and peak detector straight out of "The art of 
electronics") and AD-converter. If you want I can send you the 
schematics.

For volume recognition it's important that the distance between the 
flute and the microphone does not change. I use a headset microphone. I 
tried placing a tiny electret mic inside the flute too, but this didn't 
work well at all. I plan to glue small magnets to the keys and place 
hall sensors next to them so the keys' positions could be read by the 
microcontroller. Thus the pitch recognition only has to tell which 
octave I'm in (for non-flutists: the fingerings for most notes in the 
low and the middle octave are the same). This way I'm hoping the thing 
will be less sensitive to environment noises. It would probably get 
faster too.

On the 2002 Synth-DIY meeting in Bad Berka someone tried the thing with 
an electric guitar. It worked surprisingly well, monophonic of course.

Ingo