Waldorf Lector - Manual (Page 39)

Appendix
39 Lector User´s Manual
Appendix
What is a Vocoder?
A Vocoder is a circuitry to process the frequency content
of one signal with the frequency content of another signal.
This is done by splitting up the analysis signal (also known
as Speech signal) with bandpass filters into several
frequency bands. The volume of each frequency band is
then evaluated with an envelope follower and the
resulting envelope is used to control the volume of a
bandpass filter that processes the synthesis signal (also
known as Carrier signal). The synthesis signal therefore is
filtered by as many bandpass filters as the analysis signal
was so that each analysis filter finds its synthesis filter
counterpart.
This technique was already developed in World War II,
but the plan was to use it to encrypt speech when
transmitted by radio, rather than using it to create
musically useful sounds.
How to use the Vocoder in a musical context?
You should feed a Vocoder with speech, drum loops or
any other collection of external audio material you like.
The results will always be complex and interesting,
sometimes near to the original signal and sometimes far
away.
For the Vocoder, you always need two signals, a signal
that is analyzed and another signal that is used to be
processed by the synthesis filters. The analyzed signal
always comes one source, either an audio track or an
instrument track. The synthesis signal mostly will
delivered by the integrated synthesizer, but if you like to
use a different synthesis signal, you can route any desired
audio or instrument signal into Lector.
Use Cases
Lector in Latch Mode
This use case is great for quickly and effectively altering
the sound of a voice (especially “robot voices”) or
percussion, as the pitch would not be tracked or
controlled externally.
1. Choose a track where you would like the audio to be
processed. Alternatively you can choose a virtual
instrument track (e.g. sample player).
2. load Lector directly in one of the channel´s insert slots.