[sdiy] Tuneable CV Quantizer

[Happy Harry]

I don't think the priority would work...
as the MSB dithers... so will the priority
encoder...

H^) harry


>From: Chris Crosskey <chris.crosskey at vicon.com>
>To: "SD (E-mail)" <synth-diy at dropmix.xs4all.nl>
>Subject: RE: [sdiy] Tuneable CV Quantizer
>Date: Thu, 27 Sep 2001 19:01:58 +0100
>
>Yo ucould still use the 3914 etc if you strapped a priority encoder on it
>
> > -----Original Message-----
> > From: Theo [mailto:t.hogers at home.nl]
> > Sent: 27 September 2001 17:26
> > To: Curtin, Steven D (Steven); synth-diy at dropmix.xs4all.nl; 'John L
> > Marshall'
> > Subject: Re: [sdiy] Tuneable CV Quantizer
> >
> >
> > The most common "VU" meter ICs are the LM3914, 15, 16.
> > These can be cascaded, so more than 10 steps are possible.
> > The LM3914 is not UV but linear and might be the best choice
> > for use as a
> > quantizer.
> >
> > However all these IC have a drawback.
> > At first sight DOT mode suggest that only one output at the
> > time is active,
> > however this is not true.
> > The "levels" overlap for a few mV, so when changing from one
> > level to the
> > next two outputs are active.
> > This limits the usability as a quantizer, because when your
> > input voltage
> > hits one of the "in-between" voltages the output is the sum of the two
> > levels.
> > Especially with slow changing inputs, this may cause unwanted effects.
> >
> > I tried to overcome this by using a feed back method, so when the next
> > output gets active it pulls the input voltage up.
> > This works, but I still got short peaks in the output.
> >
> > An alternate option is to use a simple 3 or 4 bit AD build from 4
> > comparators (opams, logic gates, whatever) and a multiplexer.
> >
> > Theo
> >
> >
> > From: Curtin, Steven D (Steven) <sdcurtin at agere.com>
> >
> > > Another thing that would work is the VU meter chip (don't
> > remember the
> > > number) with the LED outputs- you then run each output
> > through a pot and
> > sum
> > > them together.  This has been mentioned in this forum many
> > times as a good
> > > tunable quantizer/sequencer.  You're limited to 10 steps, however.
> > >
> >
> >
>
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