[sdiy] more pitch shifter thoughts

[Chris CROSSKEY]

Pitch should settle down in a couple of wave cycles..... chords aren't 
really a "bass" thing so a fractionally not quite instantaneous attack on a 
VCA/VCF after the polybox should solve the problem....

chrisc
----- Original Message ----- 
From: "Scott Gravenhorst" <music.maker at gte.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, January 10, 2005 5:00 PM
Subject: Re: [sdiy] more pitch shifter thoughts


> Grant Richter <grichter at asapnet.net> wrote:
>>You can build one with just a top octave chip and a CD4046. The TOC just
>>need a high frequency clock phase locked to a reference VCO square wave. A
>>switch can select the high or low C from the TOC and give and octave above
>>or an octave below the reference VCO. (IIRC with a 50240)
>
> Being a 4046 PLL kind of guy, I have wondered about stability and tracking
> when doing this.  I have a PLL module that uses a divide by 12 counter in
> the loop and it works just fine.  But the MK50240 has a range from divide
> by 239 to divide by 478.
>
> What kind of problems, if any, will there be with such large counters?
>
> I would think that proper VCO capacitor selection is important.
>
> Over/undershoot?
>
> Does a large counter affect lag very much?
>
> My own circuit has adjustable damping for the loop filter and allows me to
> adjust it so that frequency changes are so immediate that I do not hear 
> any
> over/undershoot or lag.  But then, my PLL has only a divide by 12 counter
> in the loop.
>
>
>>> From: Steve Ridley <spr at spridley.freeserve.co.uk>
>>> Reply-To: spr at spridley.freeserve.co.uk
>>> Date: Mon, 10 Jan 2005 18:32:05 +0100 (CET)
>>> To: synth-diy at dropmix.xs4all.nl
>>> Subject: Re: Re: [sdiy] more pitch shifter thoughts
>>>
>>>
>>>>> EML PolyBox
>>>
>>>> Any idea how they did it?
>>>
>>> Schematics are available at the yahoo EMLSynth group.
>>>
>>>
>>> Steve
>>>
>>>
>>>
>>>
>>> -- 
>>>
>>> Whatever you Wanadoo:
>>> http://www.wanadoo.co.uk/time/
>>>
>>> This email has been checked for most known viruses - find out more at:
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>>
>
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