The University of Iowa makes available over 3Gb of multisampled instrument aiff files for free use. You can get them from their website. sfz doesn't handle aiff format files, so the first thing you need to do is convert them to WAV or OGG. There are various tools that can do this (WinLAME and dbPowerAmp are free - I used the latter). Optionally, you could normalise the converted files and remove the "volume=..." opcode from the mapping files.
I haven't used sfz's relative paths to samples so you need to put these mapping files in the same directory as the instrument samples. You can use a different directory for each instrument if you want.
Please remember that sfz currently loads all the samples referenced in a sfz format mapping into RAM when you load the .sfz file. For example, the complete piano will use about 2.6Gb of RAM! I've annotated the RAM usage estimate for each file. (The download size, of course, is a matter of a few Kb.) Because of this, I've provided a few different versions to let you pick the one best suited to your use.
There are more mappings on the way: I'm currently working on the Bb Clarinet - see the "work in progress" mapping below!
Other sfz format mappings
Last updated: 1 August 2004
Bb Clarinet work in progress mapping uploaded
16 June 2004: Initial version