Doepfer

> > Most of the features of that module can be realized with current Doepfer modules, but I appreciate that's not what you
> want to hear.
> >
> > A-119 for input, gain, comparator
> >
> > A-165 to invert/offset comparator output
> >
> > A-150 to switch between modulators
> >
> > You're only missing the treble boost which is rather important.
>
> Hold on, I thought the A-129-5 detected vowels vs. hissing white noise type vocal sounds, whereas the patch you're
> describing would be more to detect whether a loud enough signal's present at all..?  Or am I missing something?
>
> Thanks,
> Zoë.

Right, the A-129-5 is a bit more complicated. It is made of a treble booster followed by two filters in parallel: a 2kHz high pass
and a 1kHz low pass . Each filter is equipped with an envelope follower and a low pass (50Hz / 25Hz) for smoothing the output of the
envelope followers. The outputs of the low pass filters are processed by a comparator to generate the voiced/unvoiced gate signal.
The function is like this: whenever the level of the high pass branch  is higher than the level of the low pass branch the
voiced/unvoiced gate signal turns high. There are two internal trimming potentiometers to optimize the result: one to adjust the
bass boost in the audio input (only the treble boost is available from the front panel) and one for the level of the 1k low pass
signal.

Best wishes
Dieter Doepfer