March 19, 2022 – Bench Testing Broadcast Tools SS16.4 SN 76255

A client dug this Broadcast Tools SS16.4 Audio Matrix Switch out of a storage room a while back. We came across a need for it in one of their studios, but we could not locate the power supply at the the time. We also were not certain whether it was in the storage room because it simply wasn’t needed at some point, or if it had been pulled from service due to a failure. After ordering a new/replacement power supply for the unit, it was time to test it to see whether or not it would be suitable to install and use.

The following photos were taken during actual testing. In terms of results, the audio quality through the unit meets the factory specification of <0.01% THD+N, with input to output audio quality being 0.006% THD+N or better on all channels. The only problem found with the unit is that the “Program” button/function does not work properly for storing or recalling macros/setups. That’s not a problem in this case, since the intent is only to switch between a couple of inputs and outputs, which is quick and easy to do by simply holding down any combination of an input button and an output button. Also, this matrix switch will not be interfaced to an automation system.

Photos Of Unit During Bench Testing

SS16.4 Audio Matrix on the bench with top cover removed. It needed the dust and a few spider webs cleaned out of it from just sitting around. The unit was built in 2004, so that was really no big surprise.
Rear panel view of unit during testing.
Configuration DIP switches settings reference photo. Of note: unit is set to automatically recall the last state of the inputs and outputs when it comes back up after a power interruption.
NTI Minirator and Minilyzer devices connected to unit for testing the audio quality.
NTI Minirator MR-PRO set to produce a 1 kHz sinewave at 0.00 dBu. Next photo shows the resulting output quality of the SS16.4 Matrix at that particular setting.
Output quality measuring 0.006% THD+N, which meets the factory specification of < 0.01%. The unit was tested with a broad range of input frequencies and levels, and was also tested with the audio being fed into and out of it using both balanced and unbalanced audio combinations, all of which tested this good or better.
Reference photo of the ID/serial number label on the Broadcast Tools SS16.4 Audio Matrix.

Testing Summary

This Broadcast Tools SS16.4 Audio Matrix determined to be suitable for the client’s particular application. Again, the macro storage and recall function does not work; however, based on the simple, limited way we intend to use the unit, I see no real need to spend the time or money fixing that unnecessary function. Plans are to install and put the matrix into service soon.