Note: this post is from 2009, outbound links may be broken.
AZ Audio releases Stempel
AZ Audio has released Stempel, a freeware vocoder VST effect for Windows PC.
Contrary to many other vocoder, it’s not processing in the analog way (using band pass filters and signal followers) but in the frequency domain (in opposite to the time domain). In the frequency domain the sound representation is no more ‘amplitude versus time’ but rather a bank of complex numbers representing the magnitude and the angle of each frequency component present in a small time domain buffer. Stempel operates with these complex numbers to reproduce the vocoder effect and then transform them back into time domain samples.
Additionally, Stempel features two other frequency domain effects : two linear frequency shifters and two morphable equalizers, and two time domain effects: a saturator and a chorus.
The name of the effect ‘ Stempel’ refers to the vocoding technique, which is also called ‘timbre stamping’.
Stempel is available as a freeware VST effect plug-in for Windows PC.
Visit AZ Audio for more information.