90 degree Filter for the Format Conversion from Stereo to Mono and Mono to Pseudo Stereo
The 90° filter produces a compatible mono signal by the application of a phase shifter from a stereo-signal. The 90° filter works with a phase shifts of one side of a stereo signal of 90° and summarizes both channels. The cancellations of the parts of signal that are out of phase existing in both stereo channels are prevented by this procedure. The mono signals which are formed with a 90° filter are of substantially better quality.
The device is fitted out with balanced and floating inputs and outputs and can process level up to + 30dBu in the frequency range. Transformer balanced and electronically balanced versions are available. The gain from input to output is 0 dB.
The V724 phase shifter is adjustable between 45 and 135 degrees. With a setting of 90°, almost no cancellation of signal interests takes place. The resulting mono signal also contains the parts of the signal that gets lost with a conventional conversion by cancellation. These are, first of all, the signal interests that include the spatial impression of a stereoscopic picture. With most well sounding mix a good part of the echo disappears with a conventional conversion. For the adaptation to the program material the phase angle can be adjusted in the range of 45° to 135°.
In the standard application the V724 from a stereo-input signal produces a mono signal. This effect can be also turned around. If one chooses the mode of operation MONO TO STEREO, assistance of the 90-degree filter from a mono signal lets itself produce a Pseudo-stereo-signal.
The V724 is a standard V700 module and fits into a standard frame.