The Cyndustries List

Updated! ZEROSCILLATOR TESTING PROCEDURE 

Version 2.0      August 4th 2006

This 2.0 is an updated version of the ZO Testing Procedure 1.1 document 
and addsmore advanced trimpot calibrationprocedures for the advanced 
user or electronic technician, as well as a little more clarity on subjects 
covered previously.

You will need two other oscillators and an envelope generator to fully test 
a ZO.  (These external oscillators are referred to as the "Modulation VCO" 
andthe  "Auxiliary VCO").  

1. Listen to the Triangle Wave Output of the Zeroscillator directly and be 
certain that no other plugs are patched into the Zeroscillator.
(If you have an oscilloscope, then it is helpful to also ~watch~ this same
waveform that you are listening to...)

Leave the Big TUNING Knob somewhere near the middle of it's travel...

2. Set BIAS, RANGE, and THRU-ZERO Switches into the upright position,
(please fasten your seat-belts :)  and center the MORPHASE Switch.


3. TEST: 10-Turn TUNING Knob & RANGE Switch

Turn the big knob and listen for the pitch to change accordingly.
Do the three-positions of the RANGE Switch work?

(Without a scope there may be some doubt about the low ranges actually
doing anything or not as the ZO becomes subsonic.  To verify subsonic
operation, simply patch the Triangle Out of the ZO into the exponential 
input of some other audio VCO, and listen to ~that~ to hear if the ZO is 
working in LFO mode.  After this, please  remember to return to the 
initial set-up by listening again to the ZO Triangle Output).


4. TEST: LOW FREQUENCY SYMMETRY  (Advanced Procedure!)

Low Frequency Triangle Symmetry may be checked by tuning the ZO
to the very lowest pitch possible, (Switches Up!) and observing the?
Triangle Wave Output on a scope.  The apex of the triangle should be 
centered with left & right slopes being of equal proportions.

The adjustment for this is the long multi-turn trimpot on the CORE Board
CYN109-A , (the central PCB in the 3-card sandwich).  It is the only trimmer
on that board, and the adjustment may be made by eye.  

[ALERT: ADJUSTMENT CAN CHANGE 1V /OCTAVE TUNING CALIBRATION]


5. TEST: BIAS Switch (Linear FM Summing Bias)

The BIAS Switch Up and Down settings should have an effect on lowering the pitch in two 
different increments when it is tried under the standard set-up conditions of Lines #1 and 
#2 above.

NOTE: it is totally normal to hear ~nothing~ when the BIAS Switch is
in the Center Position, (known as "zero bias", "bias off", or "bias free" operation).

Odd behavior is also possible when the BIAS Switch is at Center Off
and there is no LIN FM Input present such as ~noise generation~ by the ZO!


6. TEST: LEDS, BIAS, LINEAR SUMMING, & THRU-ZERO OPERATION

With the ~BIAS Switch Centered~ and the RANGE and THRU-ZERO
Switches UP, you should hear nothing... Until you plug the (sine recommended) output of a 
separate Modulation VCO into the LIN FM INPUT Jack, and open-up the LIN FM Knob above 
it... Suddenly you should have some sound that gets wilder and ever more extreme the 
more you turn it up!

At this point the RED ~and~ the GREEN LEDs should be going wild bouncing back & forth 
based upon the speed of your separate modulating oscillator, (Switching this external VCO 
between AUDIO/LFO rates etc)...

Now, if you ever wonder, "What's so special about all this `through-zero'
capability, eh?" (Ok wise guy, now turn off the THRU-ZERO Switch and just
listen to half of all that fun go away! Ouch!  

Please confirm that even the GREEN LED went dark with the Thru-Zero 
operation switch turned-off).  Ok, Please return your THRU-ZERO Switch to it's proper 
place of rest in the Upright Position. 
Ahhh, all is most groovy once again...


7. TEST: DYNAMIC LINEAR FM INPUTS & VCA

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

Listening to the Triangle Output, patch one external Modulating audio
VCO into the DYNAMIC AC Coupled Input Jack (Gray jack on Modcan format
is AC-Coupled type input) (AC Coupling meaning that the input will
recognize Bipolar AC type audio signals as an input). Turn the LIN FM knob
all the way off or CCW, (Counter Clockwise).

Now patch your ~second~ Alternate VCO into the FM INDEX INPUT Jack
and open up the FM INDEX knob full. You should find that the Zeroscillator
pitch or frequency is being modulated by one Modulation VCO, while the ~Depth~ of that 
modulation is being  controlled by your other Auxiliary VCO.

Switch these two external VCOs respectively into different Audio/LFO Range
combinations for tremolo effects, or (cool nasty!) amplitude modulation grunge.


8. TEST: LINEAR FM SYNTHESIS

With the above arrangement from Test #7, please plug your external
Envelope Generator into the FM INDEX Jack instead of that second
external Auxiliary VCO... By Firing your Envelope Generator, you should be
hearing a great variety of new exciting types of metallic FM sounds emerging from your 
modular!

(just as tiny little changes to a couple of variables in a Mandelbrot fractal
equation are able to effect massive changes throughout the resulting universe it
creates...
So too are the timbres of FM synthesis wildly altered by simple changes in
the frequencies of both Modulator and Carrier and the Index of the Depth of
that modulation). The size of your temple bell, gong or glockenspiel should
easily mutate dynamically with these frequency and FM Index knob changes.

Now change your Audio rate INPUT SIGNAL from going into the DYNAMIC AC
Input Jack,  to now using the DYNAMIC DC Input Jack instead. Suddenly these
sweet FM sounds begin to sound a bit vulgar or klangorous, and as you patch your Input 
Signal back and forth between the Dynamic AC and DC Coupled Input Jacks - you can 
begin to hear a unique and subtle difference between them and that use of the Dynamic 
AC Input Jack results in sounds that are generally considered far more "musically useful 
than when using the Dynamic DC input. (Of course you can use them both!)

NOTE: in all but the banana jack versions of Zeroscillator, there is a dotted
line connecting the DYNAMIC AC Input to the LINEAR FM Input and Knob.
This is usually at rest in the fully off or CCW position, however some classic
FM Synthesis types of patches require a controlled amount of bleed-through, and the 
dotted line on the panel indicates a Switching Jack at the LINEAR FM Input that disconnects 
this controlled bleed-through ability when a jack is inserted into the LIN FM Input.

If you experience no change from the results of your Envelope Generator settings, be sure 
that the LIN FM Knob is fully off, (or the bleed-through will override the effect of the 
envelope).


9. TEST: RING MODULATOR

Unplug the Envelope Generator and plug that second Auxiliary VCO back into
the FM INDEX Input Jack and open up said such knob above the jack, ClockWise, (CW). Now 
listen to the MOD OUT Jack instead of the Triangle Wave Output...

Putting both of your External Modulation and Auxiliary Oscillators into their
AUDIO Ranges should give a resulting frequency output at the MOD OUT Jack.
Both inputs should have a say in the resulting output frequency of a Ring or
Balanced Modulator, so twiddling the FREQUENCY Knobs of ~each~ of your
two External Audio-Range VCOs should have an effect on the resulting output
pitch of the Ring Modulator. Flip these VCOs alternately DC or into LFO mode,
and you should experience some tremolo and amplitude modulation type effects.

NOTE: Please remember that this test #9 should have NOTHING to do with
the core of the Zeroscillator, you are just listening to and testing the RING
MODULATOR ~independently~ without even involving the Zeroscillator
that the Ring Modulator is mounted inside of. (Oddly, in this application
it took a while for me for this distinction to really sink in!)


10. TEST: RING MODULATION NULLING

Listen to the output labeled MOD OUT and place an External Audio VCO
(sine) into the FM INDEX Input Only, (no dynamic FM inputs). Open up the
FM INDEX KNOB and you really shouldn't hear much unless you go over
to your studio amp and crank it wayy wayy up in order to hear any whining.

Now unplug the External VCO from the FM INDEX Input Jack, and plug
it into the DYNAMIC AC INPUT JACK (Gray banana on Modcan format)...
and repeat the above. IF Only ~one~ of these FM INDEX or DYNAMIC AC
input jacks are used at any time, then you shouldn't hear any whining from the
External Modulation VCOs unless you crank the volume way wayyyyy up,
(careful, you could blow your speakers or your ears :)   


11. CALIBRATION: Ring Modulator Crosstalk Nulling (Advanced Procedure!)

(Advanced Users may eliminate balanced modulator crosstalk by adjusting trimpots VR202 
& VR203 labeled X-NULL and Y-NULL respectively for either the DYNAMIC AC or FM INDEX 
Jack inputs to be tested, and located on the top CYN 109C Modulator/ Power Board. (never 
plug signals into both inputs simultaneously if testing the nulling, and be sure to listen 
only to the 
MOD OUT when doing it).


12. EXPONENTIAL MODULATION

Listen to the Triangle Wave Output.

Plug your External Audio Rate VCO into the EXPO IN Jack and turn up the
modulation knob. Flip your External VCO into LFO Range and back to audio
and listen for the output of the ZO to react.

Leave your VCO in Audio Range and now unplug it from the EXPO IN jack and plug the 
signal alternately into one and then the other 1 Volt to the Octave Input Jacks, and the 
resulting pitches should be identical regardless of which jack is used.  This sub test is for 
"1V/Octave Input resistance matching".


13. TEST: Pulse Width Modulation PWM

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

Listen to the output marked or labeled with a square wave or PULSE wave jack.

Plug a slow LFO Waveform (or a fast one, who cares?) into the PWM Input Jack and turn the 
PWM Knob back and forth. You should hear the resulting phase changes in the output. We 
made this Pulse Width Modulation knob much more full-ranged than most as you can take 
the PWM all the way from silence at once extreme - through 50%- all the way to silence at 
the other extreme. This allows natty, buzzy little sonic textures to exist right at the bitter 
edge of the PWM.  (No "padded-cell" technology ~here~ Will!)


14. WAVEFORM SAFARI

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

This is a good time to listen to all of the other Zeroscillator waveforms!
Listen to the SINE Wave Output, it should sound a little bit more muted, or just
a little softer than the TRIANGLE Wave Output, (because it has fewer harmonics).  

(Advanced uses can observe the SINE Output on a scope adjusting 
both SINE SYMMETRY and SINE DISTORTION Trimmers VR622, & VR621
located on the top modulator board CYN109-C diagonally opposite the power
connectors). We highly recommend adjusting the sine wave to the ear, so 
ultimately in this case, a scope is actually not necessary for this calibration...

Brace yourself for a louder sound now and switch now to the two Sawtooth Outputs, (many 
more harmonics and thus rather raspy! ) While one of these Sawtooth or Reverse Sawtooth 
outs ~sound~ the same, they of course do not ~modulate~ the same. Flip the RANGE 
switch of the ZO into LFO mode and modulate and listen to another oscillator using these 
SAW Waves and one should make swoopy up glissing type sounds, while of course 
modulating that external VCO with the other SAW Output should now make swooping 
down types of pitches instead of up going ones).



15. TEST: SAWTOOTH SYMMETRY (Advanced Procedure!)

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

If you see an obvious kink in the sawtooth waveform on an oscilloscope
then adjust Trimmer VR641 (labeled SAW TRIM and located on the edge
of CYN109-B the bottom waveshaping circuit board in the three-board 
sandwich)


16. TEST: QUADRATURE  (Advanced Procedure!)

[ALERT: ADJUSTMENT CAN CHANGE 1V /OCTAVE TUNING CALIBRATION]

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

Turn both the MORPH_A and the MORPH_B Knob to full CCW or closest
to the TRIANGLE Icon next to the knob.

Have look at the MORPH_90 Output on a scope and adjust trimpot VR501
(labeled QUADRATURE and located on the end of CYN109-B the bottom
PC board in the three-board sandwich). 

Play "pin the top on the mountain" with the trimpot until the triangle looks 
complete.


17. TEST: QUADRATURE MORPHING

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

Listen to the MORPH_90 Output with the MORPHASE Switch centered.
The MORPH_B Side knob should continuously alter the shape (and the amplitude) of the 
waveform. Plug an LFO range waveform from your External VCO into the MORPH_B 
Modulation Input Jack and open the knob to see and hear your control voltage having an 
effect on the resulting MORPH_90 Output. Listen (and watch on your scope) the MORPH 
270 Output jack also...

Now Flip the MORPHASE Switch either way Off of Center.
The effect of the external voltages should stop, unless you try turning the Morph Knob on 
the other side... the MORPH_A Switch! Flip the MORPHASE Switch to see the difference in 
knob rotations, L-to-R vs. R-to-L... A control voltage into the MORPH_A Input Jack now 
will start the morphing again and you can test this by trying these changes now while 
listening to either the MORPH_0 or MORPH_180 Jacks too!


18. TEST: VARI-SYNCH

Please Return to the Initial Set-up Conditions above in lines number 1 & 2.

Open the VARI-SYNCH Knob all the way CW.

Insert an External Audio VCO signal into the SYNCH Input Jack and sweep the
External VCO up in pitch until the ZO has a very strong sonic reaction.
At this point, turn the VARI-SYNCH Knob down, if the resulting octave jumps
and harmonics disappear, well then Vari-Synch is working!


19. TIME REVERSAL

Take the above external VCO and plug it into the TIME REVERSAL Input Jack
if the Zeroscillator jumps suddenly up in pitch or phase, then it's working!


20. CALIBRATION 1/Volt to the Octave  (Advanced Procedure!)

[ALERT: ADJUSTMENT CAN CHANGE 1V /OCTAVE TUNING CALIBRATION] Right!

After the unit in question has been powered-up in a consistent environment 
for at least 20-minutes, adjust multi-turn trim potentiometer VR303 (labeled 1V and 
located on CYN109-C the board with the power connector at the top 
of the three PCB sandwich) until you achieve correct 1v/Oct keyboard tracking.

Congratulations you are done testing your new-fangled Zeroscillator type gadget!

Best Wishes!

Cynthia