Soundtracs Topaz 12 4 Manual -

The heart of the Topaz is the input channel.

The "12-4" designation refers to the console’s configuration: feeding 4 Subgroup Outputs . It is important to note that while the standard modules are mono, the master section usually supports stereo monitoring, effectively making it a 4-bus stereo mixer. Soundtracs Topaz 12 4 Manual