Most of us know at least a little bit about the Simplex 2001 and 2120 panels. Both of them had a voice evacuation option. (In fact, I think it was the same, or very similar, hardware for both.) By way of extensive Googling, here are some interesting factoids about their audio capabilities:
2001 voice evacuation systems – and early 2120 systems – didn’t use a digital audio playback module. Instead, they used an audio cassette.
The beginning and end of each message was demarcated by little bits of foil on the tape itself, which triggered a timer module that alternated between message playback and tones.
You could install multiple tape decks for multiple messages, and each tape deck could be triggered by various system events. For instance, a zone card could trigger the playback of a particular tape. Two different messages could be played back from the “A” and “B” side of each tape.
You could route those tape decks to particular speaker zones.
The idea of an eight-card voice expansion module just seems so fascinating to my geeky little brain. I really wish more information existed about the voice capabilities of these systems. What kinds of tones did they generate? What was the default message on those tapes? Was it the same punctual-sounding dude whose voice appears on Simplex panels to this day?
I can only find one video on YouTube that might possibly be of a 2001 or 2120 voice system:
If this is, in fact, a 2001 or 2120, my hypothesis is that the modern ‘high’ and ‘low’ Simplex whoop tones are recordings of the analog tone generators on these classic systems.
So, how can I learn more about 2001/2120 voice evac? Has anyone here worked on them? Does anyone have some media that just hasn’t been uploaded to YouTube yet?
Wow, good find, Wheelockfreak. Isn’t that a DTMF “111”? Is that some kind of control tone recorded on the tape itself? Surely that’s not the only evacuation tone option. Also, the drone in the background sounds like https://www.youtube.com/watch?v=Vf6Bq-vStLA&t=1m0s mains hum. I wonder if that’s being generated by the fire alarm speakers.
I installed and serviced a number of 2001 and 2120 in my years at STR/SG. I was also in Tech Support for 10 years so I did a lot of troubleshooting by telephone.
I just bought this thing on eBay. It’s called the Oscillator Control / Pre-Amp Mixer. If my calculations are correct, this is the device responsible for generating the evacuation tones on a 2001 / 2120 system, among other things. Is each one of those little daughter-cards a tone generator option card?
That is correct espiforenque. The top two daughter cards are the alarm oscillators for the primary and back up preamp channels. The top two cards are required for all systems. The lower two daughter cards are optional tone oscillators that are not included as standard in all systems.
There are two more cards that work with the Oscillator Control and Preamp Mixer (OCPM). There is a microphone interface card that has the mic connections and interface transformer. The other card is a plug in module that goes into a card rack. It is the Preamp Monitor card. It “listens” to the two channels for audio output and will cause the OCPM to switch to the back up channel if the primary fails. It also has trouble indicators for each channel.
A voice announcement unit is optional per system specs. It was tape in early systems and digital in later systems. Its audio connects only to the primary channel. The message unit silences the primary oscillator so the voice message can be heard. If the unit fails the preamp monitor card will sense loss of audio and cause the OCPM to switch to the back up channel after 20 seconds of silence.
That’s great information. Thanks! I also came across an oscillator control card, which seems to be a bunch of passive switches that connect straight to this card.
As one of those “maker” types, I love how modular these older systems are. They’re like the Moog synthesizer - Wikipedia Moog of fire alarm panels. You get a chance to see what makes 'em tick – literally, in some cases! – just by seeing how the individual parts are interconnected. I’ve learned a lot just by looking at the troubleshooting guide.
Anyway, I don’t own a whole 2001 (yet), but I’d still like to get this card working. Using said troubleshooting guide, I’m gonna try to power it up and get some audio samples of the tone generators. (Don’t worry, I’ve worked on electronics projects far more precarious than this one; I’m quite confident that I know what I’m doing. ) Retired STR-SG, do you mind if I PM you in case I have any questions?
Yeah, I failed to mention the Oscillator Control Switch Module. Yesterday was a long day so I was tired. Typically, the control switches and the preamp monitor cards are plugged into the 2 slots on the microphone enclosure motherboard.
As a vintage synth geek, I totally thought the same thing when I had a 2001. I think many of you collectors would find modular synthesis extremely fascinating.
Although the message may sound exactly like the default EST message, if you had looked in the comments section of that video, Andrew had pointed out that it’s a 2001 voice evacuation panel.
Maybe it’s the tone, or the fact that the voice doesn’t have that “digital” roughness to it, which suggests that it might be a tape. It also sounds like the same voice as in the “our hotel burnt down” video (delivering a different message, of course). The fire alarms also appear to be from approximately the same era.
PS. I’m not sure of the ethical considerations of putting someone else’s video inside my video. I did make the original title and username really clear. It’s not like there’s any royalty-free video of these systems. So, if this is your video… um, I hope you don’t mind? :oops:
Very nice work! I had no idea there were pitch and speed pots on those cards. Gotta love the tweakability of analog equipment. It would be cool to see someone build a DIY voice panel with one of these boards.
That chiming sound… THAT’S what that chime tone at the hospital I worked at was! Apparently they still have an audio-capable 2001 system, in addition to the newer 4100-series panels (the 2001s control most of the conventional pulls and smoke detectors, and also flash the light plates on 90bpm March Time.) This is also where I heard that unusual Temporal version of the 4003/4100/4120 Chime tone (the emergency wing has a “regular” 4100 voice-evac panel.)
I wonder what it’d be like with a TrueAlert speaker/strobe making those older Simplex tone generator sounds? (and knowing this hospital, it wouldn’t surprise me if they replaced a few of the old Simplex LifeAlarm speaker/2903 light plates with those.)
) Retired STR-SG, do you mind if I PM you in case I have any questions?
