|Advanced Audio Recording|
Classical Sound Synthesis the Analog Way
Modern virtual analog modeling synthesizers pretend to emulate former old school analog synthesizers up to 100% but not all of them seem to have taken common problems and limitations into account the analog synthesis "suffers" from. Here you will find some typical problems of the "incomplete" VAM technique. Well one has to note that these problems are in fact existing, because the synthesis is "too complete", meaning the model generates a clean and most accurate sound which is considered to be "dead".
Regarding the classical SST-waveforms (sine, square, triangle) there are several options to generate them:
The clean way is easy to
implement at first sight but leads to a boring sound in the first
place. Furthermore it can introduce some unwanted errors. See the article
sound generation with DDS for some details. Regarding
calculation power and resource usage, different way appear more
appropriate for this:
Later the model was replaced by mathematical equations and optimized using the C-language based compiled models for the MicroSIM Design Center together with Visual Studio 4. The usage of C-language made it easy to move the model to a real DSP later. A first approach was done in 1996 with a TMS320-System from Texas Instruments comparing VA-VCOs and NCOs as well as some filtering. Also a mathematical model was used in the ABM-blocks with Micro SIM Cadence. These blocks offer analog behavioral model calculation. The next step was the implementation of the algorithm into the DSP 56301 based evaluation system from Motorola in 1998. This DSP was strong enough to create a larger number of self oscillating filters and also additional modules to create a fully working synthesizer with. Later this was moved to the Chameleon Sound System.
|© 2004 Jürgen Schuhmacher|