I went for the "low tech" option with my desk-top computer here.
I have the Line out feeding the auxillary input of a 1980's Philips "ghetto-blaster" radio/cassette unit (remember them?).
This has treble, bass and balance knobs and a knob that you can adjust the sound all the way from Mono through to "Spatial Stereo", this has to be heard to be believed.
They just don't make gear like this any more, what's more it didn't cost me a cent, it was going to be thrown out as it didn't work.
I soldered one of the secondary wires from the transformer back on to the main PCB and we were in business again.
Here's a picture of it: