Waldorf Largo - Manual (Page 70)

Appendix
Largo User´s Manual 70
tube that can contain a certain amount of air. The player
blows air through the tube in a way such that the air starts
to vibrate. This vibration is almost completely
symmetrical, resulting in a hollow timbre.
The Pulse Wave
The Pulse Wave is the most versatile wave in a classic
synthesizer because its shape and therefore its harmonic
content can be changed in real time. This is done by
changing the width of the upper and lower portion of the
waveform cycle. These portions are called pulses, hence
the name pulse width. The width of the first pulse is used
to distinguish between different pulse waves and it is
measured in percent. The following picture shows several
pulse waves with different pulse widths:
Additive components of Pulse wave with different pulse
widths
The first thing you probably observe is that the lower part
of the wave has a narrower excursion. This is because the
energy of the wider pulse is higher than the one of the
narrower pulse. If this were not compensated, the overall
signal would have an unwanted DC offset.
As you have read in the previous chapter, the harmonic
content of a 50% pulse wave is a special case. It has a
1 3 5 7 9 11 13 15
1 3 5 7 9 11 13 15
1 3 5 7 9 11 13 15
1 3 5 7 9 11 13 15
50% Pulse
(Square Wave)
25% Pulse
<1% Pulse
(Impulse)
33% Pulse