The Cyndustries List

John Loffink wrote:

> My results.

many thanks for that efforts, John!
It would be interesting to see if two or more ZOs track the same.
(But AFAIK there's noone running more than one ZO)
To me that's even more important than the absolute precision.
I'd be willing to adjust my other VCOs to the ZO(s) if I achieved better 
tracking this way. But my applications may differ.

     Michael.


> I used the preferred ZO setting for accuracy per the manual. I did not
> adjust the ZO 1V/oct tracking trimmer.  It is at the factory setting.
> 
> Range switch: Lowest setting
> Bias switch:  High
> Tuning Knob in middle of range

> ZO data
> 
> Desired Voltage	Input Voltage	Desired Frequency	Actual Frequency
> Error (Hertz)	Error (percent)
> -1	-1.0007	15	14.812	-0.188	-1.25%
> 0	-0.0034	30	30.16		0.160		0.53%
> 1	0.9940	60	60.308	0.308		0.51%
> 2	1.9915	120	119.99	-0.010	-0.01%
> 3	2.9887	240	238.16	-1.840	-0.77%
> 4	3.9862	480	472.2		-7.800	-1.63%
> 5	4.9837	960	934.25	-25.750	-2.68%
> 6	5.9820	1,920	1841.7	-78.300	-4.08%
 >
> MOTM-300 data
> 
> Desired Voltage	Input Voltage	Desired Frequency	Actual Frequency
> Error (Hertz)	Error (percent)
> -1	-1.0007	15	14.965	-0.035	-0.23%
> 0	-0.0034	30	29.958	-0.042	-0.14%
> 1	0.9940	60	59.954	-0.046	-0.08%
> 2	1.9915	120	119.96	-0.040	-0.03%
> 3	2.9887	240	239.89	-0.110	-0.05%
> 4	3.9862	480	479.68	-0.320	-0.07%
> 5	4.9837	960	958.23	-1.770	-0.18%
> 6	5.9820	1,920	1912.1	-7.900	-0.41%
> 
> For comparison, Synthesizers.com VCO data from their web site, not measured
> by me, uses 128 Hz as based frequency.
> 
> Desired Frequency	Actual Frequency	Error Hertz	Error
> Percent
> 32		32.07		-0.07		-0.22%
> 64		64.16		-0.16		-0.25%
> 128		128.2		-0.20		-0.16%
> 256		256.2		-0.20		-0.08%
> 512		511.9		0.10		0.02%
> 1,024		1023.2	0.80		0.08%
> 2,048		2046		2.00		0.10%
> 4,096		4094		2.00		0.05%
> 8,192		8236		-44.00	-0.54%
> 16,384	16778		-394.00	-2.40%
> 
> I hope the ASCII tables don't become too jarbled.
> 
> 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
>>
>>
>>
>>
>>
>>
>>
>>Cynthia Webster wrote:
>>
>>
>>>Hi Richard!
>>>
>>>First, please be quite certain that it is the ZO and not rather
>>>that another oscillator (or keyboard) in your system being slightly
>>
>>off...
>>
>>>The Zeroscillator 1volt/octave trimmer is located on the top
>>>board where the power plugs in.   If you locate the logo
>>>saying Cynthia CYN109-C and rotate the ZO so that this logo is
>>>reading right side up, then the trimmer is the first one to the left,
>>>(right after the Tempco).  It is a multi-turm trimmer laying flat.
>>>
>>>The other two trimmers next to it are for shaping the sine wave.
>>>
>>>We also have a precision Volt to the Octave Calibration Gadget
>>>in the works as a new product which should help tune-up all of
>>>the oscillators and keyboards in any system.
>>>
>>>We're planning a revision to the manual soon to include more
>>>infoon the power connector, and the trimmers etc, but we've been
>>>way busy building Zeroscillators night & day instead!
>>>
>>>Best Wishes!
>>>
>>>
>>>Cynthia
>>>
>>>http://www.cyndustries.com/
>>>
>>>
>>>Richard Brewster wrote:
>>>
>>>
>>>
>>>
>>>>I've discovered my ZO is a little bit off on the 1V/Oct tracking.  It is
>>>>more apparent at lower frequencies.  It would be handy if the manual
>>>>pointed out the location of the 1V/Oct trimpot.  I haven't tried looking
>>>>for it yet, but I will.
>>>>
>>>>-Richard Brewster
>>>>
>>>>http://www.pugix.com
>>>>