Operation Manual

2.1 Tutorial 1. A Simple Analog Synth 24
fine knobs on the VCO panel. The speed of the vibrato can be adjusted with the frequency knob on
the LFO panel, the oscillation of the red LEDs on the panel giving you an indication of the speed
of the vibrato. As with the VCO, the shape of the output waveform of a LFO can be varied with
the wavetype selector. Try the different waveforms and you will hear how the frequency variations
of the VCO follow the modulation signal.
Note
The mod2 knob is a gain knob for the second pitch modulation input of the VCO. This input works
exactly like the first one, which means that you can use two signals to modulate the pitch variations
of the VCO. The resulting modulation signal is the sum of the two inputs. The third input signal
modulates the pulse width of the pulse wave relative to the setting of the PW knob. Try connecting
the output of a LFO to this input and then vary the frequency of the LFO to hear the change in the
waveform.
Step 3: Adding a Filter
Description
Filters are important elements of synthesizers. They are used to color the sound by altering its
harmonic content. Now, instead of sending the output of the VCO directly to the Audio Out, we
will first filter it with a low-pass filter. This type of filter, as the name suggests, filters out high
frequency components from a sound so that only frequencies below a so-called cutoff frequency
are able to escape.
Construction
• In the Filters section, select a Vlowpass2 filter and drag it into the construction area.
• You must now disconnect the VCO from the Audio Out. To do so, click on the correspond-
ing wire to select it and then delete it by pressing on the Del or BkSp key (delete key on
Mac) of your computer keyboard.
• Place the filter between the VCO and the Audio Out and then pull one wire between the
VCO output and the first Vlowpass2 input and another one from the Vlowpass2 output to
the Audio Out input.
Playing
Vlowpass2 stands for “variable second-order low-pass filter”. This means that the cutoff frequency
of the filter can be controlled with an external modulation signal. It can, however, also be adjusted
with the cutoff frq knob on the filter panel. Launch the Player and move the cutoff knob to the right