Introduction: Custom IPod Boombox Boom Box
Yeah, I know there are TONS of items out there that let you plug in your iPod on the road. However, anything that is any good will cost AT LEAST $100 (probably much more). Instead, re-purpose an existing product save lots of money, have fun making it and stop global warming :P
A while back the folks at Sirius radio teamed up with JVC and came out with a boom box for their KT-SR2000 Sirius Satellite Radio Tuner. Well I guess the idea didn't work out too well and you can now find these Boom Boxes on a number of places on the web for $20 - $40.
I am not the first one to come up with the idea of using these for iPod use but there is no published COMPLETE "hack" or instructions for doing this (There is ONE website which published one but IMO the instructions were limited and had a couple of critical mistakes). Click .here to see that original post.
I divided this Instructable into different levels: You can stop at Level 1 and get simple amplification of your iPod or go further to fully mod this Boom Box into a completely customized machine.
Step 1: Level 1: the Simple Mod
Since this unit has a convenient AUX input, we can simply take a cable with stereo male plugs on either end and connect the output of the iPod to the input of the boom box. That's it! literally plug and play.
Also, since the cradle is not made for an iPod, you'll have to find a way to secure your player if you want it to stay with the player.
You can use a rubber band, velcro or whatever to hold the iPod in place.
OR you can go further to Level #2
Step 2: Level 2: the Window
OK, so you want to somehow keep the iPod in the middle compartment and want it to look nice?
Tracing the opening of the door, I made a paper template which I then used to make a window out of clear Lexan. This takes a bit of patience to make it fit just right but it looks great when done.
Press the Lexan window in place and glue with your favorite glue. I used hot melt glue so as not to bleed through to the front.
Don't like the cable? Is this too ghetto for you?
Let's go to Level 3!
Step 3: Level 3: the Real Hacking Begins!
Here is where it gets harder. We'll go ahead and make the KS-SB200 into a true iPod accessory by adding a working dock that will connect the iPod directly to the boom box and charge the unit as well.
If you haven't already done so, take the boom box apart by removing the six screws on the back of the unit. Separate the two halves, unplug the speakers and put aside the rear portion for now. Remove the Sirius connector board assembly by removing the two screws holding it in place (keep the screws).
You can use any iPod dock to do this but I recommend any cheap one that allows you to charge the unit while plugged in.
Cut the circuit board along the yellow line and sand smooth. We need to do this in order for the connector to fit in the existing opening.
Carefully solder two jumpers as shown, these are the power and ground leads that were lost when we cut the board.
Using the outlined pinouts, use the leads from the original Sirius connector to hook up our iPod connector to the boom box control board. Note that I've only listed the relevant pinouts. All others will be left disconnected.
UV - Ground
J3 - Audio Ground
J2 - Audio Right
J1 - Audio Left
P1 - +12V
P2 - Ground
1 - Audio Ground
2 - Audio Ground
3 - Fan On (connect to + to turn on - I left it disconnected)
4 - Audio Right
5 - Audio Ground
6 - Audio Left
7 - +12V
8 - +12V
9 - Ground
10 - Ground
Use double sided foam tape to join the two connector boards and use the original screws to install in the cradle.
Put everything back together and test that your iPod charges when you turn on power to the Boom Box.
But wait, there's more in Level 4!
Step 4: Level 4: Making It Look Nice
Now that everything works well, I wanted to make it look good by painting the inside of the cradle compartment.
You can take the door off by removing the screws in the back and set it aside (watch out for the springs) OR you can mask it and paint it with the door in place. It is harder this way but I didn't want to break the door.
Mask and paint using spray paint for plastics.
Oh yeah, I also decided to make a circular opening in the Lexan "window" so that I can control the iPod while it is plugged in.
More madness in Level 5!
Step 5: Level 5: Improving the Sound
The Boom Box sounds good as is but it is heavy on the bass and you'll really have to set your iPod EQ to FLAT in order to get a nice tone.
The JVC unit uses a preamp equalizer chip from Princeton Technology and it is relatively simple to modify it so that you can change the frequency response of the EQ, remove the Bass Boost feature and even add a 3D effect. Check out the data sheet here:
I looked at the frequency response chart and decided that I would set the Boom Box EQ to the "Flat" setting with the Bass Boost still in place. This way, I can change the sound by using the iPod's internal EQ. So, I needed to remove the resistor in R83 and move it to the R80 spot. It is a little tough since it is a surface mount resistor, but be patient.
There is also a "Cycle Mode" where you can add a switch to cycle through the EQ settings, it is up to you, just follow the data sheet. Maybe I'll go back later and do this.
I could have also disabled the Bass Boost altogether by cutting the trace below pin 12 but I left it as it was (you could also wire a switch to turn the BB on and off).
There's more! in Level 6!
Step 6: Level 6: Adding a 12V Outlet
We're almost done!
So what if I'm at the beach and my phone battery is dying? I figured since the Boom Box ran on 12V DC (either batteries or DC adapter) I could install a 12V car accessory jack so that I could plug in my phone charger or any other 12V accessory.
The Boom Box runs off of 8 "D" cells, so there is plenty of juice and there's plenty of room inside the case.
Enjoy your new iPod Boom Box with built-in 12V jack!