Introduction: Ammo Box Amp
Ammo boxes are seriously cool. There is something about them that screams “HACK ME!”
When I first come across Dustinbikes brilliant ible' on hacking a ammo box into a speaker, I knew I had to do something similar.
I recently purchased a pair from my local Army Disposal store and couldn't wait to start hacking these into something awesome. I didn't want to just make a speaker out of mine, so I decided to make a guitar amp out of one instead. It also works fantastically as an MP3 speaker and has a headphone jack as well so I get the best of all worlds.
To give it some flair, I used the ends of shotgun shells as knobs. The hack itself is really quite easy and only needs a minimal of tools. The amp module itself comes pre-soldered so you don’t need any special electrical skills to make your own.
Step 1: Things to Gather
1. Ammo Box - eBay or your local army disposal store
2. Guitar Amp Kit - These can be found on eBay and I used this one. It's a 5w Tone Monster and sounds fantastic.
3. Shotgun shell caps - yes you heard right! You can buy the shotgun shells from Etsy or visit your local gun range.
4. Speakers - The Tone Monster works best with 1 15W speaker or a couple of 5W speakers. saying that I wnet with a 17.5W speaker and it works beautifully. Search eBay for what you want to use. I was going to use these ones, but decided to go with only 1 speaker
5. Computer fan grill - eBay
6. 9v battery
7. Various screws
8. Volume Control Knobs - eBay
1. Jig saw with metal cutting blade
5. Hot Glue
6. Small blow torch
Step 2: Cutting the Speaker Hole
1. Measure the diameter of your speaker.
2. Divide the length by half and set your compass to this measurement. My speaker was 100mm so the compass was set to 50mm.
3. Decide where you want to put the speaker. I put mine slightly off centre to counter for the knobs.
4. Draw a circle with the compass and then drill a hole near the inside edge of the circle. The hole needs to be big enough for the jog saw to fit into.
5. Cut out the hole using a metal cutting blade on the jigsaw. Take your time and try to keep to the line as much as possible. The hole doesn’t have to be perfect, as long as the speaker fits into the hole you should be ok.
Step 3: Drilling the Holes for the Knobs
The next step is to work out where you want to add all ofthe knobs and input plugs. I decided to add the knobs to the side of the box, but it’s up to you where you want to put them.
1. Mark-out exactly on the ammo box the volume pots on the circuit board and drill 2 holes large enough to accommodate them. Once drilled, try the pots to ensure they fit ok.
2. Next drill a hole for the tone pot and again make sure that it is big enough for it to fit.
3. The input jacks I put onto the side of the ammo box. Measure how big each of the jacks are and drill the appropriate sized holes.
4. Lastly drill a small hole for the LED indicator.
Step 4: Add the Speaker to the Ammo Box
So now you have most of the main holes drilled, it’s time toadd the speaker.
1. Place the speaker into the hole, making sure that it fits correctly. Mark out where to drill the 2 holes to attach the speaker to the ammo box.
2. Drill the holes and with some metal screws, attach the speaker to the box.
3. Make sure that you take notice of the positive and negative poles on the speaker. You might have trouble if you don’t when it comes time to hook-up the circuit board.
Step 5: Adding the Circuit Board
1. The next step is to add the circuit board. Start with the knobs lowest down in the box, in my case it was the tone knob.
2. The tone knob (pot) has 2 small bolts on it. un-do one of these and with the other one, move it so only a small amount of thread is showing.
3. Attach the pot and do the same for the other 2 on the circuit board.
4. The input jacks should also now be attached. You don’t have to worry about how much of the input jack is sticking out (plus most don’t have a second bolt). Just attach as you want to.
5. Add a 9v battery to the circuit board
6. test and make sir that everything is working as it should.
Step 6: Making the Shotgun Shell Knobs
In order to turn the knobs and to keep the theme running, I decided to go with shotgun shell caps as knobs. These are quite easy to make and look great on the ammo box
So the first thing you’ll need to do is to remove the end from one of the shotgun shells. I’m sure that there are plenty of different ways to do this (check the net), but my way works just fine. The cap (the brass section) is held in place very tightly by some plastic. It is virtually impossible to remove all of the plastic without heating it up and melting the plastic.
1. Put the plastic end of the shell into a vice and make sure that it is tight
3. With a small blow torch, heat-up the end of the cap. Do this for about 20 to 30 seconds.
4. Grab a pair of plyers and pull on the end of the cap. It should just slip off easily. If not, add some more heat and try again
5. Do this another 3 times so you end up with 3 caps
Step 7: Adding the Aluminium Knobs to the Shotgun Caps
1. You need to remove the top of the knob so you can push it into the primer inside the shell. To do this you can use a dremmel or some small wire cutters. You would also just grind it off. The aluminium is very thin so it should come off easily.
2. Next remove any excess aluminium around the bottom of the knob. This is the section that will be attached to the pot on the amp. If you don’t remove this bit, then the shotgun shell cap will stick out too much.
3. Push the end of the knob onto the primer. Give it a few taps with a small hammer to make sure it is secured.
4. Lastly add some hot glue to ensure it doesn’t come out.
5. Add them to the ends of the pots.
Step 8: Adding the Grill
1. First you need to measure out where to drill the holes to attach the grill. Once done drill holes into the ammo box
2. Add 4 screws to the grill.
3. I had some old nut-serts (kind of like smooth bolts) lying around, so I attached these as spacers to the screws. You could add some small aluminium piping or just some bolts if that is what you have on-hand.
4. Next push the screws through the holes in the ammo box and add some bolts to fasten.
Step 9: Get Jammin'
Now it’s time to plug in your guitar and try it out! It’s amazing the sound that you can get out of this small amp running on only 9v's!
The guys who make the actual amp (Called Tone Monster) have done a really good job. It’s a little on the expensive side but definitely worth the money.
The great thing about the amp is you can plug your MP3 player into it and play music through it. It also has a headphone jack and a heap of other features. The below info is taken from their eBay sit:
- 5 watts of power
- volume (also acts as the on/off)
- 5 way rotary switch for Clean, Tube, Blues, Rock, Metal & A Tuning Note
- Tone Expander Circuit
- MP3/IPOD input so you can play along with recorded music
- 9V battery (not included) or 9-15VDC power adapter (not included)
- 3.5mm headphone/ear bud jack
- recommended speaker is 2"- 8" 4 or 8 ohm rated at 5-15 watts
Let me know if you make your own and post some pictures in the comments section. If you need any help, please let me know.