MODULATION CONTROL
The MASTER MODULATION control manages the total level of modulation applied within the Hertz Donut. A
single CV input and knob provides easy performance control of modulation amount. Try patching a snappy envelope
into this input for classic FM bassline effects. If the MOD control is at
zero, you will not hear any effect while changing the slider positions.
MODULATION MIXER
The four sliders on the panel represent the modulation mixer. It is
a 3 * 4 matrix mixer that routes the three modulation sources to the four
destinations. To use the mixer, first press the button of the modulation
source you wish to select (OP A, OP B, or EXT). The LEDs on the four
sliders should turn off. Now, adjust the large “MOD” knob to maximum.
Adjust the sliders to add modulation to each destination. The slider’s LED
will light as it is changed for the first time. This means that the LED, if
lit, shows that the physical slider position matches the programmed mix
value for the currently selected modulation source.
Use care when manipulating the OPERATOR FREQUENCY slider when
it is active on both OP A and OP B sources. Circular modulation of this
type often results in unpleasant, less useful sounds. Use small amounts
of OPERATOR FREQUENCY modulation for best results.
DESTINATION LIST
AUXILIARY OUTPUT TECHNIQUES
The AUX output has a user-selectable behavior in the OPTIONS menu. You can select either operator A or B, the
sum of them both, or the digital XOR of them (resulting in a harsh sound similar to ring modulation.)
DUAL OSCILLATOR SETUP
You can use the Hertz Donut as a dual oscillator by restricting your usage of certain features. Use the MAIN
OSCILLATOR on its own, modulating the FOLD parameters as necessary. Do not use the MOD bus to affect the MAIN
OSC FREQUENCY. Use Operator A as the second oscillator, using the FINE TUNE and 1V/OCT controls. Use the
Operator menu to set Operators A and B to “Free”. You can use the MOD bus to have operators A and B modulate
each other in some way. When configured this way you have two tone generators with a different type of timbral
modulations: Phase Modulation (on the main oscillator) and Frequency Modulation (on the Operators A/B block) each
with their own output. Set the AUX OUT MODE to your desired setting. Operator A only is suggested for a "series" FM
algorithm. Operator A+B gives a "parallel" algorithm. Use the "A-B LINK" option in the Operator Menu to have operator
B correctly follow Operator A in this arrangement.
OP A:
Slider 1 -> Main Oscillator Frequency
Slider 2 -> Operator B Frequency
Slider 3 -> Phase Distortion amount
Slider 4 -> Umbrage amount
OP B:
Slider 1 -> Main Oscillator Frequency
Slider 2 -> Operator A Frequency
Slider 3 -> Phase Distortion amount
Slider 4 -> Umbrage amount
EXT:
Slider 1 -> Main Oscillator Frequency
Slider 2 -> Operator A Frequency
Slider 3 -> Operator B Frequency
Slider 4 -> Phase Distortion amount
