The Cyndustries List

Hi all,

I want to thank John Loffink for his observations and help with the
Zeroscillator.  We have had and are still having fruitful discussions
off-list that will better enable us to help you with your ZO.

The volts/oct trimmer on any VCO is always up for grabs as far as its
fine adjustment is concerned.  I'm sure many people have to adjust the
VCOs they purchase to match their keyboard or the other oscillators in
their system(s).  If any of you notice tracking problems against your
other VCOs and you believe the ZO is being operated correctly, don't
hesitate to try a v/oct calibration to bring things in line.  Please
attempt only if you have done this sort of thing before.  I suspect
I'm speaking to a savvy crowd here and most of you should have no
trouble with this.

--Mark Barton




--- In The_Cyndustries_List@yahoogroups.com, "John Loffink"
<jloffink@...> wrote:
>
> OK, I pulled out my ZO and recalibrated to get the following much much
> better results.  I would say there is a five octave range that is
very good
> by analog VCO standards.  I estimate the scale trimmer per the factory
> settings was off by 1.5 to 2 revolutions.
> 
> After final recalibration. ZO High Bias, Medium Range, Tuning in mid
range,
> base at 239.97	
> Desired Voltage	Input Voltage	Desired Frequency	Actual Frequency
> Error (Hertz)	Error (percent)	Desired Cents	Actual Cents	Difference
> Cents	
> -1	-1.0006	15	14.641	-0.359	-2.39%	-3398.25	-3440.19
> -41.94	
> 0	-0.0033	30	29.638	-0.362	-1.21%	-2198.25	-2219.27
> -21.02	
> 1	0.9941	60	59.627	-0.373	-0.62%	-998.25	-1009.05
> -10.80	
> 2	1.9916	120	119.710	-0.29	-0.24%	201.75	197.56	-4.19	
> 3	2.9888	240	239.970	-0.03	-0.01%	1401.75	1401.53	-0.22	
> 4	3.9863	480	480.530	0.53	0.11%	2601.75	2603.66	1.91	
> 5	4.9837	960	960.140	0.14	0.01%	3801.75	3802.00	0.25	
> 6	5.9820	1920	1911.000	-9	-0.47%	5001.75	4993.61
> -8.13	
> 
> Compared to my MOTM results from yesterday:
> 
> MOTM VCO	
> Desired Voltage	Input Voltage	Desired Frequency	Actual Frequency
> Error (Hertz)	Error (percent)	Desired Cents	Actual Cents	Difference
> Cents	
> -1	-1.0007	15	14.965	-0.035	-0.23%	-3398.25	-3402.30
> -4.04	
> 0	-0.0034	30	29.958	-0.042	-0.14%	-2198.25	-2200.68
> -2.43	
> 1	0.9940	60	59.954	-0.046	-0.08%	-998.25	-999.58	-1.33	
> 2	1.9915	120	119.96	-0.040	-0.03%	201.75	201.17	-0.58	
> 3	2.9887	240	239.89	-0.110	-0.05%	1401.75	1400.95	-0.79	
> 4	3.9862	480	479.68	-0.320	-0.07%	2601.75	2600.59	-1.15	
> 5	4.9837	960	958.23	-1.770	-0.18%	3801.75	3798.55	-3.19	
> 6	5.9820	1,920	1912.1	-7.900	-0.41%	5001.75	4994.61	-7.14	
> 
> I can get slightly better results for the ZO in the bass registers,
to -5.98
> cents at 60 Hertz.  But that occurs at the expense of the higher
registers,
> and it is the higher registers that are more sensitive to tuning
errors.  I
> doubt that tuning at 15 or 30 Hertz is relevant.  The ZO is now
calibrated
> to track the MOTM to within about 3 cents over a five octave range.  You
> can't expect much better than that.
> 
> The error (Hertz) difference shows what would be the beat frequency.
 This
> is what might cause beats and clangorous tones.  Worst case beat
frequency
> is about 2 Hertz, which shouldn't cause the artifacts with indexed
FM that I
> described in previous posts.  Mark is working with me offline to
understand
> other causes for this.
> 
> John Loffink
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com
> The Wavemakers Synthesizer Web Site
> http://www.wavemakers-synth.com
>