[sdiy] PLL examples

Scott Gravenhorst music.maker at gte.net
Fri Jan 6 00:55:20 CET 2006


Alwyn Lloyd <zarquin at ucc.gu.uwa.edu.au> wrote:
>
>Well,
>Funnily enough, i have one of those that i bought as a kit..
>it worked and made some awesome noises, though it didn't seem to track
>accuratly on a guitar... though i didn't have a compressor in front, which
>would have probably improved it quite a bit..   still quite fun to play
>with though :)

Guitars are notorious for trashy output signals.  What really confuses a PLL
is the fact that a guitar signal can have more then 2 zero crossings per wave
cycle.  Also a PLL, especially a 4046, likes a rather large signal.  The 4046
data sheet says it's best if it's rail to rail.  A guitar signal loses
amplitude over time as it rings, so while it may track fairly well when the
string is first picked, eventually it will die out enough that the PLL won't
have enough to work with and will get confused by the zero crossing thing.  

A PLL can be a useful tool when used with appropriate signals, the output of a
VCO is very easy for a 4046 to track over many octaves.


>
>Cheers,
>Alwyn
>
>On Fri, 6 Jan 2006, Loscha wrote:
>
>> That "Mini Synth" was a project in a series of educational projects "Dick
>> Smith Electronics" had in the mid/late 80s through to early 90s. They were
>> commonly available, and there would be several thousand of those in various
>> states of functionality across the country, I'm an Aussie, but, I've never
>> had the fortune to find one.
>>  I'm ready, though, cause I have the original book here. That's the only
>> muscial project in it, though, sadly :|
>> It is an interesting project, that displays a wide gamut of uses for the
>> 4046. If used correctly, I'm sure the 4046 could be a secret weapon of
>> synthesis, it's got a high bang-per-buck ratio.
>>
>> -ed
>>
>> On 1/6/06, David Moylan <dave at westphila.net> wrote:
>> >
>> > Yeah, I built this one on a protoboard.  A compressor in front helps a
>> > lot, but still I didn't have good luck with it holding pitches.  Noise
>> > from the guitar would gate the PLL tracking circuit and it would 'freak
>> > out'.
>> >
>> > Dave
>> >
>> > Colin Raffel wrote:
>> >
>> > > That one is a good example, but I personally like the slightly more
>> > > complex one here:
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%201.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%202.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%203.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%204.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%205.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%206.jpg
>> > > http://experimentalistsanonymous.com/diy/Schematics/Guitar%20Synth%
>> > > 20and%20Misc%20Signal%20Shapers/Mini%20Synth%20like%20Super%20DF-2%
>> > > 20Page%207.jpg
>> > >
>> > > It is an article from a magazine, and it has no distortion circuit
>> > > and lots of room for features and improvement.  I always thought it
>> > > would be interesting to put a pulse wave into the trigger in so that
>> > > it tracked at any rate-sort of like a sample-pitch-and-hold-it for a
>> > > guitar or any instrument.
>> > >
>> > > -Colin
>> > >
>> > > On Jan 5, 2006, at 1:54 PM, Loscha wrote:
>> > >
>> > >> A little unusual, but, the the Boss DF-2 uses a CD4046 to generate  a
>> > >> sine wave an octave or two above your input tone to simulare  feedback
>> > >> http://experimentalistsanonymous.com/diy/Schematics/Distortion%
>> > >> 20Boost%20and%20Overdrive/BOSS%20DF2.pdf
>> > >>
>> > >>  You should be able to Dx7 style FM with a couple PLLs, but, I  might
>> > >> be wrong on that one.
>> > >>
>> > >> On 1/6/06, amokan <amokan at gmail.com> wrote: Can anyone recommend  any
>> > >> 'quick and dirty' PLL examples related to music circuits on the  web?
>> > >>
>> > >> thanks.
>> > >>
>> >
>> >
>>
>

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