quadrature audio

[Paul Perry]

At 02:12 PM 14/04/99 +0200, Martin Czech  wrote:
>what could be usefull applications for a wideband audio quadrature
>circuit?  Ie. a circuit that offers some delayed versions of the input
>and where the outputs have (allmost) 90 DEG phase difference?
>
Isn't this required for frequency shifting?
(that is, adding an arbitrary number of Hz to each component of the
input signal, NOT generating a harmony)

paul perry melbourne australia