stereo vectorscope

Using two UAAl 70 LED voltmeter ICs it is possible to construct a novel type of stereo indicator which gives a display determined by the amplitude and phase relationship of the two inpu t signals. ICI is fed with the left channel signal and drives the rows of a 4 x 4 LED matrix , whilst IC2 is fed with the right channel signal and drives the columns of the matrix. At r any time one LED in the matrix will 1../ be lit depending on the instantaneous amplitudes of the two input signals. Since AC signals are being fed to the circuit the display will be continuously changing, the pattern produced bei ng dependent, not only on the amplitude but on the relative phase of the two signals