Operation Manual

2.1 Tutorial 1. A Simple Analog Synth 23
for woodwind sounds. The sawtooth wave contains all the harmonics, but its higher frequencies
are softer than in the pulse wave; it is good for brass-like sounds and strings. The noise wave, as
its name indicates, consists of white noise; it is good for unpitched percussion. Note that when a
pulse wave has been chosen, its shape can be changed with the PWM (Pulse Width) knob.
Before going on to the next step, go back to the Builder by choosing Show Builder from the
View menu or use the Ctrl-T/Apple-T shortcut.
Step 2: Adding a LFO
Description
To add some life to our synthesizer, we will use the output of a LFO (Low Frequency Oscillator)
to modulate the input of the VCO. A LFO is an oscillator which generates sine, triangle, square
and random waves with a frequency varying between 0.1 Hz and 35 Hz. The frequency of a LFO
signal is so low that it cannot be heard; a LFO, therefore, is not used to produce sound but rather
to generate control signals which modulate other signals. In our patch, we will use this signal to
vary the frequency of the VCO (i.e., to produce a vibrato effect).
Construction
• In the Generators section of the Browser, choose the LFO module and connect its output to
the first input of the VCO. This input is a pitch modulation signal. This means that the pitch
variation will follow the shape of the input signal.
Figure 9: Tutorial 1, step 2
Playing
Now switch back to the Tassman Player. To hear the effect of the LFO, turn the mod1 knob of the
VCO to the right and you will start to hear the frequency varying. The mod1 knob is simply a gain
knob that adjusts the effect of the input signal by multiplying it by a gain. When the knob is fully
turned to the left, the gain is zero, which means that the input has no effect. As you turn the knob
to the right, the amplitude of the modulation signal affecting the VCO increases so that you hear a
deeper vibrato. The frequency variations of the vibrato are relative to the settings of the coarse and