The Hidden Sounds Of The Past

If you stop to think, the number of pre-recorded voices and sounds you might hear on an average day might number in the hundreds. Everything from subway announcements, alerts on your phone, to sound effects at Disneyland is a sound that triggers in response to an event. [Techmoan] came across a device that many of us have interacted with, but likely never seen: a humble Sontranic 9A Announcer.

In their heyday, these sorts of devices formed the backbone of audio feedback. Messages from Father Christmas were recorded and could be reached when calling a number. Sound effects in theme parks that were activated when a ride activated some hidden switch. Anything where the sound effect needed to play on some sort of trigger.

An interesting thing to note is that this is not a reel-to-reel system. The tape is of the standard 1/4″ magnetic variety, perhaps a little thicker for extra durability. It instead sits in the top of the machine; coiling and uncoiling like a two-dimensional lava lamp. Additionally, there’s nothing clever about detecting the beginning or end of the audio loop (as there were four copies of the same recording on this particular tape). In fact, everything about this machine speaks of reliability as the most important design consideration. A reel-to-reel system would just add more points of failure.

After a little bit of diagnosing, [Techmoan] managed to get the device running again and found the message on the tape to be from the phone system, informing the listener that the line is no longer in service. This banal message is perhaps the best testament to the ubiquity of devices like these.

Perhaps in the future, we’ll see an instrument like this magnetic tape-based one created from a similar machine to the one [Techmoan] found.

20 thoughts on “The Hidden Sounds Of The Past

  1. That looping tape is oddly mesmerizing. A lava lamp was an apt comparison. I wonder how it would work vertically? A flat panel, with just the tape and minus the audio hardware making up the bulk of the base, would make an intriguing mobile wall display.

    1. I think it was called an EchoPlex. They were sort of fragile and tempermental beasts. I used one back in the early 1980’s on the road. When they worked, they were great.

      1. The Mellotron used a whole bunch of seamlessly repeating tape loops all running around several shafts to pack as much length as possible into the upright piano sized cabinet. To play, there was a piano-like keyboard. Connected to each key was a playback head which would be lifted into contact with its tape loop by pressing the key. A slight amount of volume control was possible by using less key pressure to make the head come just close enough to pick up the magnetic fields. It would take a very fine touch on the keys to vary the head motion in the very short range between just picking up the signal to contacting the tape.

        The inventor tried to make a budget model that plugged a row of 8-Track tapes into the back of the console but only a few were built due to it being very unreliable.

        In recent years there have been new Mellotrons built with some upgraded features, which can be retrofitted to some original models.

        They’re a rather bespoke item of analog audio gear that can be very well simulated digitally, like a Leslie speaker, but some people just have to have the real thing.

        1. This is incorrect. The Mellotron used 8-second linear tape strips hanging inside the machine which were engaged mechanically by key pressure transferred to that strips capstan roller. If you held down the key for more than 8 seconds, the note stopped playing. Mellotron players often adapted a style of periodically lifting a key in a chord which needed to last more than 8 seconds to help mask the note time limit.

    1. I can’t speak for the loops used in the telephone machine, but for tape echo machines and 8 track, lubricated tape was used.
      Allegedly, one of the reasons why Ampex tape is very sticky these days, is because they didn’t use whale oil, while the rest of the tape producing world stuck to whale oil for their tape lubrication.
      Don’t think of ‘lubrication’ as an oily layer on the tape, it’s really imperceptibly little oil.

  2. Kind of cool for a retro item. I just wish he’d dug in a bit more and figured out how to get the amps working. There are only a couple of possibilities – bad caps, power supply or his theory about enabling. Given there are some almost 40 year old electrolytic caps in there, I’d look at that.

  3. My first job, fixing the very first generation of answering machines, involved the clear box of tape and the metal strip that tripped the electrodes at the end. I was a kid in high school and the place had shelves shelves of dead units. The owner made a really big mistake that I was very thankful for. He was about to pay me $3 an hour to work on them and than thought the better of it and offered me $10 for each one I fixed. He pointed me to the very large pile of them and a place to work and left me to it for a few hours. He came back to my having a big pile of them on the floor next to me. He laughed and told me I was not going to find any that worked in the pile. I told him I knew that, those were the ones I fixed so far. Yea, I cherry picked the easy ones at first, a lot of them just needed to have the electrodes cleaned and the tape heads cleaned. I had one at the very end that was really hard and a few that took over an hour, but man, that was good money back in the day.

  4. 3 notes not to pitch ascending scale. Think-sing “GTE”, then in an Ernestine voice “the number you have dialed is not a working number”. Generous Telephone Company before Vorizon.

    We also had dial a movie, what’s on at all the screens. And of course time and temp, brought to you by the local big grocery.

    This was high tech when voice operated was the way! “Operator”, I want name or exchange and xxxx.

  5. I started working out of college at SMC (Sono-Mag Corporation in Bloomington, il) assembling cartridge systems for radio stations. The Carousel (rotating drum) and Cara-Stat (held 20 carts each with their own play head) played 30 and 60 second commercials from a predecessor to the 8track. One machine we built had two huge 8track like cartridges…one for “at the tone the time is “hour number”…and the other for ” minute number”. This article brought back memories.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.