Part 1
For quite a while I have been thinking about building a CD player to look like an old Victrola Phonograph player. Since I had plent of other projects on my plate, this gave me time to mull over my ideas and also to start looking for parts. I didn't want to spend much money on what would be a kind of goofy project, so almost all the parts for this project came from yard sales. The total cost for this project was definitely under the $50 mark.
The first step was finding a good box. I didn't want to build a full scale phonograph player, so I looked for something the size of a small humidor or a shoebox. I ended up finding the perfect thing at a yard sale, an old wooden box with brass hardware and a great patina. I later found that the hardware was actually iron or steel with brass plate, which is why I didn't end up polishing the existing hardware, I didn't want to scrub off the brass!
The CD player was a standard Philips CD walkman that I bought at a yard sale for a buck or so. It is new enough to have a 45 second buffer, which is nice since it will pay flawlessly while people examine the finished product hands on.
The CD walkman came apart pretty easily. I found that the actual CD reading aparatus was separate from the main circuit board, which was a major help to this project. I didn't have to route a large irrgular hole in the top of the box, instead, I just drilled three small holes for the three cables that needed to connect to the main circuit board. The CD reading module simply screweed into the top lid of the box, while the circuit board is installed on the inside of the lid.
In the above photograph, you can see the pencil layout of the controls and other components that are due to be mounted on the CD player. In retrospect, I should have drilled all the holes at once and installed all the switchgear at the same time. It would have led to slightly neater wiring in the end.
The CD controls were the next problem to tackle. The CD player originally used a board of membrane switches connected to the main board by a ribbon cable. I was initially worried about how to tap into this wiring, but after trancing the membrane switches and testing with a multimeter, I found that the electrical layout of the buttons was pretty simple, all buttons shared a common ground, and all the switches had a signal line that was directly accesible at the ribbon cable mounting point on the ciruit board. A bit of delicate soldering later and I had a standard pin header connected to the CD player circuit board.
The switches were the most expensive part of the project, since I had a particular type of switch in mind. I used spring loaded toggle switches to create the three necessary controls for the CD player, Play/Pause, Previous, and Next. Finally I used a non-spring loaded toggle swith for power. On the back of the player, I installed a 5V power jack and a 3.5mm stereo line out jack. My plan for the CD player didn't call for amazing audio quality as a standalone unit, but I wanted to have an available high quality line out for integration into my home stereo system. At this point, I assembled the CD player and switches together and gave it a quick test run.
I wanted the CD player to be authentic with a mono speaker and a brass horn acting as a passive amplifier. I ended up buying a brass horn meant to be a christmas decoration for $2. The horn had a loop in it, so I sawed off both ends of the horn then soldered them together without the hoop. With some sanding a coat of black paint, you can't notice that the horn was not straight to begin with. The only problem with the horn is that it is very small. My original plan called for finding a larger horn, but after months of looking at yard sales and on eBay, I never found a horn that was the right size and price. If I ever find one, I can add it later.
The amplifier was the trickest part. A test attaching a small speaker to the headphone output of the CD player quickly told me that I would need an amplifier to get a reasonable volume level. I bought a pair of amplified speakers at the local discount store, but the amplifier circuit was bad, and the circuit board was so cheap that it fell apart when I tried to do repairs. Finally, I settled on tearing apart a cheap iPod speaker dock I got at the nearest JC Penny (a great source for cheap iPod/iPhone accessories). The simple iPod dock didn't have a volume control or a line out jack, but I soldered together a simple volume control with a stereo audio pot, and a line out jack with built in switch that mutes the internal speakers when an audio cable is plugged in. The amplifier also turned out to be a bit quieter than I had hoped. I plan on upgrading it in the future when I come across a suitable amp for the right price.
Finally, I created brass plates with printed labels using the "toner transfer" method commonly used for etching cicuit boards. I scavenged the brass from some brass hardware meant for holding door knobs. I carefully measured and cut/drilled the brass to have the right sized holes to install the switches and jacks. Using photoshop, I created a set of labels, which I printed out backwards. Using a clothes iron set to its highest setting, I ironed the printouts onto the brass plates. I repeated this a number of times before I hit a working combonation.
First, make sure that you are ironing on a surface that won't conduct too much heat, and won't burn after prolonged exposure to the business end of the iron. I used an old piece of scrap wood. Your ironing board cover will probably melt if you use it. Secondly, the brass plates have to be relatively rough. The toner wouldn't stick when I polished the plates with steel wool and scotch-brite, so I used 600 grit sandpaper to rough up the plates. I cleaned the brass carefully with soap and water, then with alcohol. I then put the brass onto my board, and carefully position the backwards printouts (on standard copier/printer paper) on top of them. The iron then goes on top. Pressing down with the iron is required for about 5-10 minutes, then i used the edge of the iron to gently make sure the iron had heated the brass plate evenly. Finally, dump the hot brass plate into warm water (be careful, it is VERY hot). After lettting it cool for a few minutes, the paper will easily peel off, and the toner should have stuck to the brass. The toner is on there quite securely, you can't get it off without steel wool. There may be a bit of paper stuck to the toner, you can rub it off with your finger nail. Even my final toner transfer wasn't perfect, but it turned out about 95%.
Final assembly involved wiring everything together. I used hot glue to mount the interior components, and every wire has a removable connector in case I need to change out a component later.
On the left, you can see the amplifier circuit, the speakers, and the volume knob. There are stereo speakers, but I have one line disabled on the amplifier. The speaker glued into the bottom corner sends sound out of the brass horn. The large circuit in the center is the CD player board, connected through the top to the laser and motor. On the far right you can see the bottom of the switch pannel. In the bottom of the box, you can see the power and line out jacks. The rest of the space is not needed, perhaps I can store some CD's in there. The LCD display is still connected to the CD Player, although it is not visible when the player is closed, I found it helpful to keep for debugging.
The CD track is surrounded by an aluminum ring (made out of some scrap aluminum I had in my garage), and covered in felt. I planned to cover the entire CD mechanism besides the spindle with felt, but the gap between the mechanism and the CD is too narrow for a piece of felt to fit. I tried raising the CD up, but the laser is unable to focus on the CD beyond an extra 1/2 millimeter. I considered using thinner green cardstock, but it looked cheesy. I think the finaly soultion I came up with to use felt on everything but the CD mechanism is a nice compromise.
I'm pretty happy with the final result. My only two gripes are that the horn is a bit smaller than I had hoped, and that the amplifier I used is not loud enough. I plan on replacing both components in the future if affordable alternatives fall into my lap. One possible obstacle is finding a larger amplifier that runs on 5V power. If this is not possible, I may consider using the 12V DC to 5V + 12V power supplies found inside USB hard drive or USB CD-ROM drive cases.
Update: I have continued work on the phonograph and now have the new horn and amplifier installed. See the results in...
