The Cyndustries List

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