The U790 is a stereo phase shifter with a wide adjustment range that makes it possible to adjust the phase difference between the input and output of stereo signals. Very interesting tonal effects are also possible which are not producible with equalizers; the phase difference between channels can create spatial effects in the stereoscopic picture of a complex music signal.
The device is fitted with balanced and floating inputs and outputs and can process signal levels up to + 30dBu in the frequency range.
The U790 makes it possible to change the phase displacement between the input and the output. A phase difference of 10 degrees between both stereo channels will lead to a recognizable deterioration of the signal quality (signal smearing). On the other hand, interesting spatial effects can be achieved by adding phase displacement in the stereo signal.
If the phase angle is much bigger than 360 degrees between input and output, another effect occur which can certainly be identified by the human ear. The separate spectral components of a complex audio signal are delayed by phase displacement differently. Because the ear interprets a sound on the basis of the transients and recognizes a relevant phase difference between input and output by the different movement of the phase of the separate harmonious changes to each other, the composition of the signal in the transients and with it the sound impression. Whether and to what extent this effect is audible, depends, on one hand, on the amount of the phase difference, and on the other, the structure of the signal is of crucial importance in this effect; More concise transients, will result in bigger change. With a soft, single note it will not be possible to hear the effect, however, with a more complex music signal astonishing changes, which can cause an improvement, or a deterioration of the subjective sound quality will occur.
The phase angle between input and output can be adjusted with a potentiometer in the range between 0° to 720°. A phase displacement between both stereo channels has an effect directly on the stereo basis and on the spatial impression of the stereoscopic picture. A pot enables the adjustment of the phase difference up to 90° between both channels. This effect is strongly dependent on the program material. In every case the mono compatibility must be checked constantly when applying this function. Dependent on the phase relations between both channels in the original program, interesting smear and widening effects can be achieved. This function is also useful for the production of Pseudo-stereo signals from mono sources.
The U790 is a standard V700 module that fits into a standard frame.
