Here is a little guide for a free sound canvas emulation. It uses Timidity, a free soundfont and some configuration.
It can be used with all versions of Timidity.

1. Download DJ Tony's Roland SC-55 1.1 Soundfont and if needed, rename it to "DJ Tony's Roland SC-55 1.1.sf2" (Google should help)

Use my Attached configuration file.

Cannot really find v1.1 of that sound font, only v1.0.
But then again I have doubts anyways about to what extend it resembles real soundcanvas hardware.
Also MS Direct-X comes supplied with a softsynth and a licenced 22KHz soundcanvas patch set (gm.dls).

Updated Version