How To | Control Standby of SPA amp via GPIO of a Core

Learn how to use a GPIO port to control the standby state of a SPA amplifier.

Updated at June 8th, 2023


It is possible to control the QSC SPA amp's standby (STBY) state with a Core's GPIO Output (also from an IO8-Flex GPIO Output).  The SPA typically expects a simple contact closure on its STBY pins, however the Core 110 and the IO8-Flex do not have contact closure outputs.  They do, however, have Digital (TTL) outputs which can be used.  One must take care, though, to wire the GPIO Output to the SPA's STBY contacts with the correct polarity, even though this is not explicitly defined in the SPA documentation or on the silkscreened information on the rear of the SPA amp.

Looking at the rear of the SPA amp, the left-most contact of the STBY connector is the "positive" or triggered input, and the right-most contact is the "negative" or grounded contact.  Therefore, the Core (or IO8-Flex) GPIO Output to the SPA STBY contacts MUST be wired as below.  Any GPIO Outputs, configured as a Digital TTL pin, could be wired to the STBY contacts of the SPA amp.