Polarity inverter stereo amp trick

There is a trick with analog and digital amps to make a mono signal to stereo putting two amps. one amp putting a polarity inverter at input and output of the amp for one channel and the other amps with no polarity inverters for the other channel.

this makes a really nice stereo effect without any ugly modulation.

would be great to have polarity inverter block or better yet amps with stereo option doing this trick internally