The Cyndustries List

What is the quoted and/or typical tracking accuracy for the zeroscillator? I
assumed it would be five octaves or better. Also, does it use an internal
precision voltage reference or does its tuning vary with the power supply
voltages? I was just about to pop for one of these before the price increase.

Barry

--- In The_Cyndustries_List@yahoogroups.com, Richard Brewster <
pugix@...> wrote:
>
> My testing method isn't a problem. The output impedance of the source
> doesn't matter for the measurements I did. I adjusted to get 1.000
> volt, as measured at the 1V/oct input. (Measured at the output pin of
> the op amp in my mixer, the voltage would be 1.010 volts, because of the
> 1K/100K divider formed between the mixer output and the 1V/oct input on
> the ZO.) Tracking two oscillators isn't the main point here. ; It's the
> irregularity of the response of a single VCO over several octaves. If
> something was amiss with my test method, it would have shown up on the
> MOTM-300 too.
>
> -Richard
>
> John Loffink wrote:
>
> >Richard,
> >
> >For your testing, what is the output impedance of your Mixer-Comparator?
> >Unless it is the range of ~100 ohm or less, it may cause some of the error
> >you are seeing.
> >
> >An MOTM 820 VC Lag has a properly designed output for accurate 1V/oct
> >tracking. You may want to put your voltage source through that for your
> >measurements.
> >
> >For any broad tracking between ZO and other VCOs, I am thinking you
may need
> >to use a soft sync function between them. No matter how accurate the
VCOs,
> >there will be differences in beating through the audio range. Because one
> >VCO is used as a modulator, the beating may sound more prominent than
two
> >VCOS that are simply mixed in parallel.
> >
> >John Loffink
> >The Microtonal Synthesis Web Site
> >http://www.microtonal-synthesis.com
> >The Wavemakers Synthesizer Web Site
> >http://www.wavemakers-synth.com
> >
> >
> >
> >
> >>-----Original Message-----
> >>From: The_Cyndustries_List@yahoogroups.com
> >>[mailto:The_Cyndustries_List@yahoogroups.com] On Behalf Of Richard
> >>Brewster
> >>Sent: Sunday, February 26, 2006 6:27 PM
> >>To: The_Cyndustries_List@yahoogroups.com
> >>Subject: Re: [The_Cyndustries_List] ZO 1V/Octave calibration
> >>
> >>Thanks, Cynthia. I found the trimpot easily.
> >>
> >>I ended up with a setting close to the original factory setting. But I
> >>was not able to fix a problem of the ZO tracking sharp in the lower
> >>octaves of the high range. I started down this calibration road because
> >>I noticed that the ZO and the MOTM-300 being used as the FM source in
> >>the starter ZO patch were not tracking each other well. The beats were
> >>quite noticable. I spent a couple of hours taking measurements, after
> >>setting the 1V/oct trimpot. Here's what I found.
> >>
> >>I measured with a digital voltmeter and a digital frequency counter.
> >>For comparison I performed the same tests on the MOTM-300 VCO. The
> >>results were all obtained by the same method and instruments, using the
> >>same power supply. I created a 1V source by a mixer with bias (my own
> >>mixer-comparator) and measured for 1V at the 1V/oct input jack. For
> >>each reading I dialed up a frequency, applied 1 volt and recorded the
> >>new frequency, which ideally is double for the next octave. For the ZO
> >>I did this in all four combinations of High/Low Bias and High/Mid
> >>range. I only measured what I could dial up that started in the audio
> >>range. Each number pair below represents the HZ value before and after,
> >>so 30/60 means 30HZ/60HZ.
> >>
> >>Low Bias/Mid Range
> >>30/60 - right on
> >>60/119.8
> >>
>; >>Low Bias/High Range
> >>30/66
> >>60/123.2
> >>120/241.5
> >>240/480 - right on
> >>480/957
> >>
> >>High Bias/Low Range
> >>30/60.2
> >>60/120 - right on
> >>120/239.7
> >>240/478.4
> >>
> >>High Bias/High Range
> >>30/66
> >>60/124
> >>120/243
> >>240/482
> >>480/960 - right on
> >>960/1916
> >>1920/3825
> >>
> >>MOTM-300
> >>30/60 - right on
> >>60/120 - right on
> >>120/240 - right on
> >>240/480 - right on
> >>480/960 - right on
> >>960/1918
> >>1920/3834
> >>
> >>The ZO tracking isn't bad, but it isn't great either. The ZO starts out
> >>on the low end tracking more than one octave per volt (sharp), passes
> >>the sweet spot and starts going flat gradually. By contrast the
> >>MOTM-300 tracks perfectly over about six octaves and then also start
> >>going a little flat. Now this flatness on the high end may be by
> >>design, due to psycho-acoustic effects, I seem to recall. I'm not a
> >>music VCO expert. But sharpness on the low end isn't good.
> >>
> >>For my ZO the tracking is accurate over at best about three octaves.
> >>The lower octaves track better in the low range and the higher octaves
> >>track better in the high range. This was a useful finding. Of course I
> >>tested only my own ZO, so I can't say whether this is the general
> >>character of a ZO or not. Still, I would be interested to hear from
> >>other ZO owners whether they are able to replicate my findings.
> >>
> >>-Richard Brewster
> >>
> >>http://www.pugix.com
> >>
> >>
> >>
> >>
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> >>
> >>
> >>
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
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