[sdiy-interim] Fwd: PLL (4046) for pitch tracking?

[David Moylan]

I built a circuit from an article I found online.  I can't remember
where I found it.  It's 7 scanned pages that describe a dual 4046 pitch
tracker with 1 octave up/down switching on each that I think was
available as a kit.  It has some basic gating circuitry to hold the 4046
pitch when the signal gets too low.

I've used it with guitar and it has a little glitch at the beginning of
a picked note, not too much octave jumping, but it sucks during the
decay.  It doesn't have enough signal pre-treatment for a guitar and
it's simple hold scheme isn't sufficient (mostly in figuring out a
proper gate).

It does however do cool things to non-harmonic percussive sources - like
electronics drums and cymbals and would probably work well on some
woodwinds where the player can cut the notes off quickly.

I have an almost complete board for Craig Anderton's Rocktave Divider
which I'd like to pick the fuzz signal off of (should be a reasonable
square at fundamental freq.) to try to drive the PLL.  The Rocktave has
a fair amount of LPF followed by a compressor which smooths the input
and makes up for higher notes being rolled off.  (note the NE570 also
used in the Boss)  I think it would give a much better signal to drive
the PLL.  It also has an output VCA which follows the input level, so
the octaves fade out as the signal is fading towards a point it can't
track.  Using a PLL in a sort of effects loop in the Rocktave might work
well.

Oh, just remembered.  The Rocktave article and the "mini synth" (PLL)
article can both be found at generalguitargadgets.com.  Search 'synth'
to find the mini synth.

Dave

Loscha wrote:
> Don't believe the manual!
> It functions in it's pitch tracking mode over quite a wide range ---
> it outputs a toothy wave to the "tuner out" port on the back in pitch
> mode.
> 
> http://www.loscha.com/fidgety/rps10-master-schematic-450dpi.gif
> 
> This is my scan, from a schematic I purchased, hope it helps some people out.
> I have the rest of the manual, if anyone needs a hand to get their
> RPS-10 calibrated.
> 
> On 3/29/07, Andre Majorel <aym-htnys at teaser.fr> wrote:
>> On 2007-03-28 23:57 +1000, Loscha wrote:
>>> On 3/28/07, Gorka Garcia <torpedo at demadrid.com> wrote:
>>>
>>>> Has anyone tried a PLL (4046, for example) for pitch tracking?
>>>> Maybe to make a pitch to CV converter for a theremin or a mono
>>>> played guitar
>>> Boss RPS-10,
>>> has a pitch tracking input in the back for it's pitch shifter mode.
>>> Uses the 4046.
>>> Tracks quite well, has a good enough range to use of the majority of
>>> the guitar's neck (the highs are filtered by the input stage, I
>>> haven't opened it up, but, I imagine it would only get better as you
>>> ascended into double digits of kilohertz.
>> The manual says C5 through C7, C6 being the neutral point. That's
>> 500 Hz through 2 kHz.
>>
>> --
>> André Majorel <URL:http://www.teaser.fr/~amajorel/>
>> Do not use this account for regular correspondence.
>> See the URL above for contact information.
>>
>> _____________________________________________________________________
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> 
> 
> --
> www.loscha.com
> 
> 


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