Simplex Microphone

Has anyone ever seen one of these before?

Probably part of a Simplex master clock or Voice Evac system.

I never actually saw one of those microphones but I know we had several models in the 5100 intercom and sound product line. The others were private labeled models from Shure. The one in the picture most likely is too.

The 5100 equipment was all private label manufactured for Simplex. The 5120 intercom equipment was all made for us by Valcom. When that was developed we had an exclusive contract with Valcom on the equipment. Something like 10 years before they could sell it themselves or distribute it to others. Valcom now sells an updated version as the Muitipath system.

interesting, had to add to a multipath system in a simplex building recently and was wondering if they had a connection.

Probably used for an intercom or PA system.

I doubt it was used in FA, however i could be wrong…

Just wondering, while working for Simplex, did you ever come across a 2001-style public address system? My workplace had one of these, but I haven’t seen anything about them online. The system had two 2001 cabinets with full glass doors (black door frames with locks on the side). The cards inside were of a very similar style to the ones used on a 2001 fire alarm panel, and it used the same main control card as a 2001 fire alarm system (the one typically labeled “FIRE/TBL CONTROL”). It seems like a strange setup since it looked extremely similar to a 2001 fire alarm panel, yet it was clearly designed to be used as a public address system.

There never was a 2001 public address system as such. That is not a common application but not unheard-of either. I am sure it was a 2001 audio fire alarm system without any IDC components, just the audio equipment. You did not say what the workplace was but apparently the owners felt the PA system was important enough to be supervised so they could be sure it would function in an emergency situation. Sort of a precursor of the current mass notification systems.

The main difference between that 2001 audio equipment and a standard PA system is that the 2001 audio system is fully supervised. In the 2001 if a speaker circuit got cut or shorted, a trouble would come on the system so it could be repaired. The same with the amplifiers. Those are supervised so if an amplifier fails a trouble is annunciated on the system. There is also the capability that a backup amplifier can automatically switch in to cover for the failed unit. Again, the amplifier trouble tells the facility owner that service is needed. On a standard PA system these failures are only found when an announcement is made and people do not hear it because of failures.

We had a similar application in a brewery using a 4100+ system. When the building was built around 1971 a supervised sprinkler system was installed. A subsequent owner decided that the facility needed to be monitored for all of the hazardous gasses that could leak. An audio 4100+ was installed to monitor for the various hazardous gasses in the departments. Those were ammonia, CO2, and some others I don’t remember. The system was outfitted with a custom voice message set. Through programming it could automatically announce the type of gas that was detected and the area. This way employees could evacuate in a direction away from the hazardous gas release area.

When originally installed it was not used as a fire alarm system. At some later time fire alarm devices (stations and smoke detectors) were installed and the system took over monitoring the sprinkler system. Since it was originally installed as an addressable system this was an easy and logical conversion. The fire alarm devices created a FIRE indication on the panel and used an audio message for that. The hazardous gas detectors used the PRIORITY 2 capability built into the system and still made those specialized announcements.

Thanks for the explanation! That sounds like an accurate description of the system. The building is a museum, so I have no idea why they would have opted for a supervised system. The system isn’t used for any important announcements or special applications.