Sunday, October 22, 2017

Building a Seeburg Wall-O-Matic Interface (Part 1)


Last year we moved into a house that had some interesting touches left by a previous owner. Most notably, there was a "play room" decorated in the style of a 50's Diner. It had a booth, table, chairs, and plenty of decoration. We joked that this room's decor was what sold us on the house!

In any case, one notable thing missing from this room was a jukebox! Or at least, taking things slightly more sensibly, the jukebox controller that such diners often have sitting at their tables. It was at this point that I started learning all about the iconic Seeburg Wall-O-Matic.

Flash forward a year, and I was finally in the process of resurrecting my electronics workbench. I started watching a few too many EEVblog videos, built a shelf/bench setup using components from Ikea, unpacked all the gear I'd kept in boxes for a few too many years, and even made a few upgrades.

The one thing I desperately needed? Projects! Given that I knew I was going to have a lot of free time coming up in the near future, I reopened my research into the Wall-O-Matic and began to scour eBay.

Background Research

One of the first things I stumbled across were these commercial "products" designed to provide a modern interface from the wallbox:

CD Adapter

Unfortunately, these projects were less than desirable for my tastes. I was also looking for a project, not an off-the-shelf solution. These devices also seemed a bit dated, of limited availability, and quite proprietary. They also seemed to focus on playback a bit too "locally," rather than using the wallbox as an actual remote for a real stereo system. My house had in-wall speakers installed in many rooms, including the "diner" room, and I really wanted to use those. Since I had already connected many of my in-wall speakers to a Sonos rig, I kept wondering if there was a way I could just use that.

The next thing I did was dig into these hobbyist projects which seemed much closer to what I actually wanted to accomplish:

Wall Box SONOS Controller [Stephen Devlin]
Seeburg Wall-O-Matic [Retro Future Electrics]
Raspberry Pi Project – A 1960s wallbox interfaced with Sonos [Phil Lavin]

One common theme among these projects was simplicity. Minimal components to interface the wallbox to a Raspberry Pi, and minimal work to control a Sonos system based on the result. They also provided enough schematic and component details to give me a tangible starting point. Even if I decided to take a different path with my own project, at least I had a good foundation to build upon.

Project Goals

So thinking through what I wanted to accomplish with this project, I decided I wanted to build a device that could do the following:
  • Provide power to the wallbox
  • Read the signal pulses, and decode them into a song selection
  • Enqueue selected songs with my Sonos system, simulating the functionality of a jukebox
  • Electronically toggle the coin switches, so that inserting actual coins would be optional
At a lower level, I also knew I wanted to take things seriously in the design of the circuit I was going to use to accomplish all of this. That meant:
  • Complete and detailed schematic
  • Complete and detailed BOM (bill-of-materials)
  • Real fabricated PCB (printed circuit board) design
(The BOM and PCB being things that I'd never actually done before. Every prior circuit of mine was a hand-constructed mess of wires on a pre-drilled pad-per-hole PCB. Thankfully, in this day and age, doing it "right" is now quite accessible.)

I'll attempt to break this blog series apart based on the major progression of this project. I may not discuss things in the actual order that I did them, since there was a lot of back-and-forth between the various elements. However, it should flow in an order that makes sense. Most likely it'll be something like this:

1 comment:

Steve Hammer said...

Thanks so much for posting about your project. Your pulse decoding circuit saved my bacon on a similar project using a wall-o-matic 100 that I started in December. I tried my own hand at making a circuit for the decoder, but after much testing decided that now matter how much tweaking I did, it wasn't going to work reliably. Sadly I didn't find your post until I had tried it my way. My 3W1 will eventually be hooked up to a Raspberry Pi running Fruitbox, but the premise is similar to yours. A 65 year old front end to a digital device! It's an awesome idea. Thank you, thank you, thank you!

Steve Hammer