Ultracheap Soundboard

[JakeSoft]

OK, let me first start off by saying the sound from this board is pretty lackluster. It makes a cheapie Hasbro soundboard look like a Crystal Focus, but in my mind sound is still better than no sound. I decided to take on this project purely for the fun of it as a way to experiment with adding sound to a saber while staying within a very tight budget. I also wanted to use up some spare components I had lying around (1.25" sink tube blade holder, 2.2 Ohm 5w resistor, Lux III Red, 4 AA Battery Holder) and make a saber out of those components that I'd mainly use for heavy dueling.

The setup documented here gives these sounds:
1. Power-up
2. Power-down
3. Several clash sounds
4. Idle hum (sort of)
5. Swing (sort of)

Why sort of? Well, on this kind of budget you've got to be willing to make some sacrifices. There is no sensor on the board dedicated to making the swing sounds happen so they just kind of happen randomly intermixed with the idle hum. That's probably the most annoying thing about it. If you are holding it perfectly still then it'll still make random swing sounds at pretty regular intervals. This is less of a problem if you are dueling intensely and keep swing it around.

Another sacrifice is that the sound quality is probably about 8-bit and not very impressive, but good enough to get the point across. It is pretty loud, however.

Who would do this? Well, probably nobody except those who want to upgrade a stunt saber with sound for super cheap. Maybe you are adverse to putting a $100+ sound card in a saber you intend to smack the heck out of. Anyway, I spent the time to figure this out so I thought I'd give back to this community that has taught me so much by sharing what I learned.


I found a website where you can buy three of these things for about $25 shipped. That's $8.33 for you math wizards. I added about $3 of parts (5v regulator and a P-channel MOSFET) on top of that for a total of about $12. These might not be strictly necessary, but I didn't want to overpower this cheap board by putting a full 6 volts through it nor did I trust it to handle the 1.5A of current that the Lux III Red would run at. So, I regulated the voltage into the board and bypassed the high-amp draw LED with the MOSFET. See wiring diagrams later on in this post.


Here it is opened up. It's a clam-shell design that comes apart by backing out a few screws on the reverse side. I've taken a couple of these apart now and there always seems to be at least one screw that's an absolute bantha to get out. Luckily, these are made of very cheap flimsy plastic so I was able to pry it open anyway in both cases. It's still easier than cutting open the heavily glued Force Action toy lightsabers.


To keep a long story short, after some experimentation and probing with my multimeter I determined that this is how the board is laid out. I was able to remove all of the hardware wired to the board by simply (and carefully!) heating the existing solder on the board and pulling everything off. The only thing I left on the board was a small capacitor on the reverse side. The yellow "O"s are where the speaker is wired in.

These things come with a primitive swing sensor that is used to activate the clash sounds. What? OK, that's weird. I guess that's fine if you want to duel with the air, but I want to duel with other sabers. So, I wired in a clash sensor available right here at TCSS for a very reasonable 0.25 USD.


The switches were soldered right to the board (the blue things in the pic above). I guess I could have tried to heat the solder and remove those, but I opted instead to rock them back and forth until the pins broke off. That left the pins still securely soldered to the board and gave me an anchor point for my creative rewiring later. The switches control the light outputs and sound outputs independently. That's stupid; I wanted the light and sound to come on at the same time. So, I installed a jumper between the high-side of each switch so that I could trigger both at once with a single momentary switch.

Another thing to overcome was that the light activation switch wasn't simply on/off operation like the sound switch is. It cycled the LED from Red, Green, Blue, and Off states. So, I wired the Red and Blue to the gate on the MOSFET and left the Green floating. This worked as it turned 4 possible states into 2, which is what I wanted.


I wired in the rest of the components as pictured above.


I discovered that the speaker that comes with this unit is the perfect size to fit inside the gasket that comes with a 1.25? sink tube. I was able to use Super Glue to just stick the speaker inside of the gasket. The gasket in turn fits perfectly at the base of the sink tube.



I wrapped the entire assembly in electrical tape and stuffed it into a hilt. So far it's working fine. The only annoyance is that sometimes (very rarely) the sound and light still get out of sync if I don't push the activation switch hard enough; I'll get sound but no light or light and no sound. When that happens, I just hit the kill switch twice and it resets itself. After a little practice I'm sure I can overcome that.


I'll try to get a YouTube video up soon showing how it's working. The clash works perfectly and sounds pretty good too. Here is pic of it how it stands now. The hilt itself is still very raw; I need to add some overlays and grips and stuff. So far the entire project has been done just to prove it can be done and indeed it can.

Update 6/20/2014: Adding video.