Project Name: Spy
Project Description: These are small amplifying spy devices housed in silicone coin purses. They do not transmit or record information and are absurdly dysfunctional tools for storing data. When used in a group, the act of surveillance becomes an odd form sousveillance and all that is amplified is, essentially, already there.
What motivated the making of this: metadata, NSA leaks, massive data collection, corporate surveillance, sousveillance, modes of resistance, what-is-privacy, the performing of security…
Step 1: Gather Your Materials
- LM 386 op amp
- 47 ohm resistor
- 10 K ohm potentiometer
- electret microphone
- 10 uF capacitor
- 470 uF capacitor
- 220 uF capacitor
- 0.047 uF capacitor
- 0.01 uF capacitor
- 9V battery clip leads
- 9V batteries
- ear buds
- silicone coin purses from the 99¢ store
The circuit is based off of DIno Segovis’ ½ watt LM386 Audio Amplifier Project. His tutorials are great. http://hackaweek.com/hacks/?p=131
Step 2: LM386
Solder the chip onto the perf board making sure you don’t damage any legs and that none of the legs are touching.
Step 3: ------> the First Components
Solder the 10 uF capacitor so that the negative lead is connected to pin 8 and the positive lead to pin 1 of the chip. Clip the excess leads.
Step 4: -----> Some More
Connect the positive lead from the battery clip to pin 6. I have added a toggle switch between this lead and the chip in order to preserve battery life.
Step 5: The Rest of the Components--->
Connect pin 6 to the positive lead of a 220 uF capacitor and to a 47 ohm resistor. The resistor then goes to a .0047 uF capacitor that then goes to ground. The 220 uF capacitor goes to a 47 ohm resistor which is connected to the positive lead of an audio jack. The negative lead of the jack goes to ground.
Note: I used a stereo jack and connected tip and ring together as the positive lead.
Pins 4 and 2 go to ground. Pin 3 goes to a .01 uF capacitor which then goes to the signal (middle pin) of a 10K potentiometer as well as to the positive lead of the mic. The negative lead of both the mic and the potentiometer go to ground. The positive pin on the potentiometer goes to a 10 k resistor which then goes to power.
Step 6: ---> Test!
To denoise it a bit, I added a decoupler: 470uF capacitor between power and ground.
Step 7: ---> Insulate
Dunk the circuit in plasti dip. Be mindful not to wet the audio jack, the battery clip, the toggle switch or the mic. This will insulate the circuit so that you can cram the battery inside the same container and no component other than the mic will become mcirophonic. The plastic insulation helps to make the circuit less delicate should you choose a flimsy encasing as I did. Hang them on the clothesline to dry…
Step 8: --->
Find a little housing for them…. I used silicone coin purses which did not require drilling holes to fit the components since cutting through silicone can be done extremely easily. I replicated these circuits and this process a number of times, made some instructions manuals to accompany them and got them out of the privacy of my garage and into someone else’s private space.