Here is my take on the suitcase / briefcase portable audio unit.
I wanted something portable and getting some ideas from the internet including here, I put into a plan of what I wanted to do.
I've been doing projects for years and for the first time I thought id post on here to help anyone in their project designs by giving them ideas.
I have seen many people putting speakers and amps into a suitcase with some batteries so I thought , hey why not put a Hi-Fi system inside the suitcase instead! The only drawback with this is the battery capability due to its circuitry ; not an issue for a stereo that's on an adaptor at 12v, easy to adapt.
It had to sound good and clear without any of the vibrations of the suitcase interfering with the music, so this is my project. :)
Step 1: Gather Materials and Scrounge
- Stereo system of any description which will fit into the suitcase. ( I brought this one from carboot for £10 with faulty cd player )
Dab digital radio
- Hard plastic briefcase - ( Found at car boot for £2)
USB / SD card reader audio player ( £3 china )
Bluetooth audio usb dongle - ( eBay £4 )
Glue gun with plenty of glue sticks
Self tapping screws
Push to make switches
Step 2: Preperation and Measuring Up
Started by stripping down the stereo system & Dab radio system down to the necessary parts which I wanted.
Put the briefcase on the bench and used A4 pieces of paper across the front, taped together to cover the whole front side ( as I didn't have any masking tape at the time )
Placed the circuit boards from the stereo and dab radio on top of the paper for measuring and placement in the final stage.
Drew an outline of each board to gauge the correct placement when cutting and placing; including the whole board size regardless of any curves or cuts.
DISPLAY AND SWITCH MEASUREMENTS:
Now that the boards are drawn up and sized , I had to mark out the position where the display to the stereo will be in conjunction with the front panel PCB .
I measured up from the edge of the board to the edge of the display and marked up on the paper.
Did the same measure from the top of the board to the top edge of the display.
With the buttons and volume pot control ,measured from the centre and then to the edge of the PCB.
With the Push buttons, used a ruler to measure the thickness of the switches, thus finding the correct sized drill bit for the job.
I marked up the speakers by measuring from the centre of the speaker cone to the outer edge of the speaker carcase. Then offered those measurements up to the briefcase to draw the outline of the actual speaker unit, with a little help from a hole cutting tool for cutting wood.
Step 3: Cutting Out.
Once I marked everything up I cut out the holes for the speakers, switches and display using a couple of drill bits , a special hole cutter attachment used for wood , and a hot air gun to melt the display opening and using a sharp knife, cutting around the display shape.
I also used the same hot air gun technique to cut out at the top a space for the included USB / SD media player I had. ( Melting plastic smoke , don't breath this! )
The push button holes in the middle were a little tight so, I had to twist the buttons in place to get them to fit.
Step 4: First Fix of the Stereo PCB
I Mounted the panels into their positions from the inside of the briefcase to make sure I got the measurement right.
In the picture the green PCB is the stereo front panel , along side is the amplifier / audio circuit board from the stereo.
At the bottom was the dab radio tuner which ended up being positioned on top of the front stereo PCB with plastic stand offs.
At this point when everything is in place and fits fine, I had the task of wiring up the circuit boards.
Since a lot of micro hifi systems contain so many boards in a compact case, they were modular and so the boards had 90 degree connectors which attached them all together, so I had to crack out the service manual and wire up.
The front control board had one of these connectors which in turn connected to the amplifier PCB , I had to connect each pin (1 to 27 ) in order to the amplifier board from the front control board including all signal lines for correct operation , which I found out beforehand.
I wanted everything to work off the stereo system when you change sources such as CD and Tape, but earlier on in the build this didn't go as planned.
The dab radio was meant to run from the CD Player function of the stereo which included turning it on with power (6v ) and using the Cd player DAC audio lines, but this failed to work so I resorted to using the Aux in function for it and the USB / SD Media player box. It became easier .
Step 5: Adding the Media Box.
Once the radio and dab were up and running , I next installed the media box.
This was placed at the top for convenience.
The audio output was also connected to the Aux input of the stereo system , but I put in a selector switch to keep them from interfering with each other =]. a Crude final option I made to make things easier.
Step 6: Final Fix Placement.
My crude final finish of the boom box , it works fantastic now and turns heads when I use it out the front washing the car or mowing the lawn. I kept the original power supply from the stereo for simplicity , and for the fact it wouldn't be worth using batteries for this as the amplifier is 15v with a Negative 15v line as well so it was easier to keep it in.
The speakers were attached using small self tappers to the front of the case. The main amplifier board was affixed to the speakers at the back, with plenty of clearance for the back to close.
Although due to the heat from the heat sink, I cut a hole at the back of the briefcase and used the original speakers front mesh to cover the hole to prevent dirt intrusion.
I put the antenna at the top and affixed using a piece from the Real Robots building set which was perfect to hold the antenna in place . I kept the original radio on the hifi as well as the dab radio which also uses this antenna, affixed together using ring connectors.
The end result is what I wanted out of this project, this was a test for me to see if I could do it and here is the result. I will admit its not the best one on here and ive seen far better ones , but this is something I built and still use to this day , as I actually made this back In September 2014 during my downtime. Its not the loudest, but it is punchy at 25w per speaker.
This is my first instructable and hopefully not the last , I may have made some mistakes and skipped out some parts , but I will probably end up with a MK2 of this later on down the line.
This was my attempt at one of these suitcases .
Thanks for taking the time to read :) .