Analog modeling synthesizer
A virtual analog synthesizer emulation in a digital manner the behavior of the circuits of an analog synthesizer, by calculating the behavior.
The calculation can be on a computer ( as a software synthesizer), or on a specific hardware on which DSPs ( Digital Signal Processors) and a pre-installed software are to happen.
Virtual analog synthesizer came to the invention of the physical modeling - a synthesis of form, the physical vibration generating forms tries to imitate by digital models - in the late 1980s, and experienced in the 1990s, a boom, first as hardware solutions, then (from about 1997) is purely software based. Some well-known synthesizers of this kind, such as the Clavia Nord Lead and Access Virus, became cult devices. Also, companies like Waldorf, Novation or Oberheim able to establish on which the VA synthesizers sector.
Critics - mostly fans of analog synthesizers - complain that in this process the sound a loss would arise: Since the resolution (measured in kilohertz of frequency representation and in bits for the amplitude) determine the precision of the calculation process, is the sound only at very high resolutions realistic. In addition, is the property of analog synthesizers to produce unpredictable, but co-responsible for their sound character flaw, not replicable, and therefore the sound of virtual analog synthesizer " sterile " than the originals.
The counter-argument is put forward that in the today common resolutions ( 96 or 192 kHz / 20 or 24 bit) by the resolution -related differences for analog sound are as good as inaudible. Decisive so is the quality of the model used and the accuracy of calculation used, in which, due often compromises are made due to the limited computing capacity. Due to simplifications of the algorithms more votes may be calculated on synthesizers. On the other hand, in modern virtual analog synthesizers emulating the "error" analog devices are also increasingly addressed and implemented in the waves algorithms.
An existing problem is that in most synthesizers are controlled by the MIDI protocol, which has only 7-bit parameter and this is almost always applied especially at VA synthesizers on the internal parameters. This result in low values for the controlled eg the volume, vibrato or Filtergrenzfreqenzen comparatively coarse gradations. Then set a frequency-determining value for a filter, which is only at 50, be reduced by 10 %, but are available only 5 levels. Therefore, all must be smoothed artificially by the internal control group or external devices incoming change commands to avoid audible levels, while the parameter variable potentiometers are specified directly in the classic analog devices. This applies similarly for the MIDI -enabled ( retrofitted ) analog synthesizer, which only use the note information and for the control of the modules also have a potentiometer.