VirtualMIDISynth is a free, lightweight (only 1.5MB!) and efficient SoundFont player for Windows (only).
It is implemented as a Windows multimedia user driver, so it is directly accessible as a standard MIDI Out device.
Note that VirtualMIDISynth can also convert Midi files to .mp3. This way you can easily get a JJazzLab backing track as an audio file. See the FAQ for more info.
Download JJazzLab-SoundFont.sf2 from the Musical Artefacts web site
Download and install VirtualMIDISynth from the CoolSoft web site (accept all installer default settings)
Load the Soundfont in VirtualMIDISynth
Click on the pen icon if you need to adjust the default volume (0-500%) of the SoundFont.
In the Midi Options/Preferences, set VirtualMIDISynth as the JJazzLab out Midi device
Go to the Output Synth Editor and apply the preset ‘VirtualMIDISynth’
This setup has to be done only once, the settings are restored automatically when you restart JJazzLab.
The Midi Configuration Wizard will automatically perform steps 4 (if VirtualMIDISynth is installed) and 5 if you choose to use the JJazzLab SoundFont.