Simple time delay circuit?

[Mark Hammer]

Depending on what it is you're trying to acheive you might also want to look into all pass filters, or even the Blumlein shuffler:
http://www.audiosignal.co.uk/Resources/Stereo_shuffling_A4.pdf

One of the things that I suspect led to the demise of the BBD-based stereo image enhancers was that the surface noise of vinyl and cassette tape is almost exclusively channel specific.  So when you derived what was unique to each channel, and cross-fed a bit of it to the other channel, you were effectively increasing the overall amplitudeof surface noise from the playback medium.

Of course, use of shuffling in the studio would be on near pristine equipment and otherwise low-noise media.  When applied to what end-users had i their hands, it could prove annoying unless one took scrupulous care of your recordings.

But, reading the Blumlein/shuffling document, it would seem that the image-enhancers simply took that one step farther by adding the short delay element.