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Step 10: Adding an Audio Amp and Volume Pot

Picture of Adding an Audio Amp and Volume Pot
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Once I had built the synth I decided that adding a small amp and volume pot would allow me to really annoy everyone in the house. It's a easy add-on and definitely worth including in the build. The amp I used can be picked-up on eBay for cheap and I have included a link in the parts section.

Steps:

1. Check out the schematic. I have highlighted the added amp and pot and also where they are connected. In the schematic the symbol for the amp is missing the ground wires for input and output. Check out the other schematic which I did which will also help work out hownto wire this up

2. Connect the ground and positive on the amp to the 9v battery.

3. The input section on the amp should be connected as follows: positive to pin 3 on the 3rd 555 IC and ground to the ground section on the circuit board

4. The output should be connected as follows: positive to the positive solder point on the speaker and the ground to the ground solder point on the speaker

5. To add a volume pot I found that the best place to connect it is to the output socket. If you add it directly to the speaker I found that it caused some interference to the synth and changed the sound. Adding it to the socket isolates it from the speaker and stops the interference.