1. I have found that some Radio Shack stores have the same model box w/ or w/o a PCBoard.
I use a separate PCBoard and shape it to fit. I use a 2 wheel grinder and use the fine
wheel, not the coarse. It can also be cut to fit with a utility knife quite easily.
1a. The box has 4 little 1/4" feet for the PCBoard to screw down to, although the screws
are not supplied. They do supply screws for the lid. Once the PCBoard is shaped and fits
nice, drill holes in the PCBoard to mount it to the feet. Try to use as much of the
PCBoard as you can.
2. There is JUST enough room inside for all the components. I have used this
LAYOUT plan and found it to work really well. Of course there are other ways,
so be creative. The 9v battery will fit nice and snug between the capacitors.
3. Start by soldering the resistors and capacitors to the PCBoard. (the PCBoard referred to
here, is a Project PCBoard) It has metal solder rings on the bottom side for each hole.
Make sure to get this kind, some project PCBoards do not have the solder rings.
4. Once the resistors and capacitors are soldered in place, it's time to start to wire them
together. The wire should be color coded for ease.
red=right white=left black=shield (ground) Any colors will do as long as both I/O
are the same. Try to use the smallest, quality (AWG) gauge wire you can find.
The larger the number, the smaller the wire. (i.e. 0/1awg=a nickel 24awg=a pin head)
Cut each wire to about 4 inches in length. You'll need 6 lengths. You'll also need a few
lengths of the same color wires for other connections.
4a. We'll start with the Mic IN jack. Solder the red wire to one side of one of the resistors.
Solder the white wire to one side of the other resistor. I use a piece of the capacitors
wire lead (the part cut off when you soldered it to the PCBoard) to act as a ground and
power distribution block. Shape the lead in the form of a "U", then simply insert the
leads into the PCBoard near the back end next to the capacitors. Solder the leads to the
PCBoard. Keep all components on the PCBoard spaced far enough apart to avoid any possible
touching of the other connections or components. Solder the black wire to one of the leads.
Since there will be 2 "U" leads, one for ground and one for power, make sure you use the
correct leads.
4b. Continuing with the Mic IN jack, Solder a length of red wire to the other side of the
resistor you used for in 4a. Solder the other end of that wire to one of the power "U" leads.
Solder a length of white wire to the other resistor and then to the SAME "U" lead you just
soldered the red wire too. Wire layout is important, so you don't end up with a rats nest
of wires going every which way. Take your time, layout each length of wire prior to soldering
and you'll find it will be much easier to follow and will look much better.
4c. Still with Mic IN, Solder a length of red wire to the SAME resistor red wire you soldered
first in 4a. Solder the other end to one of the capacitors leads. Now solder a length of
white wire to the SAME resistor white wire you soldered in 4a. Solder the other end of this
wire to one of the leads on the other capacitor. Now with a piece of heat shrink tubing
(1/8" diameter) group the 3 wires, red/white/black together leaving at least an inch of the
wire tips exposed or you WILL have trouble soldering them to the INPUT jack.
5. Now we go to the OUTPUT side. Solder the red wire to the other capacitor lead used in 4c.
Solder the white wire to the other capacitor lead used in 4c. Solder the black wire to the
SAME "U" lead as the other black wire in 4a. Group them with heat shrink tubing as in 4c.
6. Now for the battery leads. The wires from the snap connector are quite long, cut em down
to about 3 > 3 1/2 inches. Group them with heat shrink tubing leaving about a 1/2 inch of
the tips exposed. Snug the tubing up to the connector as you heat it. You should only have
2 open leads left on the PCBoard, one from each of the "U"s. Solder the red wire to the
power "U" and the black wire to the ground "U".
7. Now that that's all done, set it aside and grab your box. You will need to be VERY careful
when drilling the holes for the 1/8" I/O jacks. Remember the saying, MEASURE TWICE, CUT ONCE!
As I said there is VERY little room inside the box and the jacks need to be mounted EXACT or
there could be a problem with either, fit or touching each other. The jacks will be mounted
to either side of the box and they will just miss touching each other, so it's pretty critical.
You'll see there are 4 larger feet that the lid screws down to, the jacks will have to be
mounted AS CLOSE AS POSSIBLE to 2 of them, even notching them a bit to be safe they don't touch.
Once you have your spot measured and marked off it's time to drill. Use a drill bit long enough
to go through both sides of the box. This will ensure they are nice and even.
REMEMBER TO RUN THE WIRES THROUGH THE HOLES BEFORE SOLDERING TO THE JACK!!
You'll probably find it much easier to run the wires through the hole rather than mounting the
jacks. Would be VERY hard to solder with the jacks mounted.
7a. Screw down the PCBoard assembly to the box.
7b. Start with one wire at a time, cut the wire to length and solder it to the jack, making sure
each jack is soldered the EXACT same way. You may need to test to make sure left is left and
right is right, so don't make a final product yet. Make sure to slip a piece of heat shrink
tubing on each wire BEFORE soldering. The space is VERY tight and protection from touching
is a MUST! The longer of the leads on the jacks are the grounds or shields.
Red wire is the right channel and the white wire is the left channel.
8. Now that you have the jacks all soldered and the channels are correct, go ahead and mount
the jacks in the holes you drilled in the box. Make sure to get PANEL MOUNT jacks.
They'll have a screw ring that sandwiches the back mount of the jack and the plastic of
the box. Label your IN and OUT jacks. You can use a label from an audio grade Maxell DAT,
They usually come with a bunch of small labels, one being MIC. Be Creative.
9. Snap in your 9volt battery, Screw down the lid and your all set!
