Figure 1: Front View of the Audio Channel Equalizer Before Disassembly
Figure 2: Close-Up View of a Potentiometer
For this lab, my partner and I disassembled an audio channel equalizer (Figure 1). At first, we weren’t exactly sure what the machine that we chose was. The machine was a metal box with 24 rotating black knobs on the front and several holes in the back where wires and cables could be plugged into. Later, we learned that the device was related to audio and sound and that the various little knobs on the machine were connected to potentiometers which are resistors that rotate to provide variable resistance (Figure 2). This change in resistance is what adjusts the frequencies of the audio, and I thought that was really interesting because it’s cool how the things we’re learning in class are actually in everyday things. All of those circuits with resistors and capacitors and such that we draw in class are actually utilized in devices like this one, and I think it’s really clever how someone used the change in resistance to adjust the audio outputted.
Figure 3: Inside of the Audio Channel Equalizer
When we were taking apart the channel equalizer, we decided that it was best to take out all of the screws first. After taking out all of the screws, we could pull off the metal frames of the machine. We learned that the metal frames were made of galvanized steel and that the metal itself was folded to form the rectangular prism frame (Figure 3). The holes in the frame were punched in by a machine (Figure 4). Since these holes were punched in, we assumed that the frame itself was machined uniquely for this device, but the parts such as the screws and knobs were most likely off-the-shelf parts which makes sense because they are much more common and seem to be easier to mass produce.
Figure 4: Back View of the Audio Channel Equalizer
Figure 5: Close-Up View of EQ/AM Input Boards
After taking off the frame, we saw that the inside had 8 EQ/AM input boards connected to the knobs’ potentiometers (Figure 5). I haven’t gotten the chance to look at the insides of many machines, so seeing all of the input boards and how they were connected to each other and the knobs was really cool.
Two of the input boards were previously broken off of the potentiometers, but the rest of the circuit boards seemed fine (Figure 6). We detached a green cable that was connecting each of the input boards. It seems like the majority of the parts of this machine were meant to be replaced. The parts such as the circuit boards, the knobs, and the potentiometers could be taken out and replaced with new ones. Additionally, because the frames had screws instead of, for instance, glue, this channel equalizer was most likely designed to have been taken apart and put back together, especially since the knobs could be pulled off by hand.
Figure 6: Components Inside the Audio Channel Equalizer
After taking out all of the circuits and knobs as well as the potentiometers connected to the knobs, we were pretty much done disassembling the channel equalizer. The parts such as the knobs, nuts, and screws seemed like they could be reused or recycled. However, the other parts, such as the metal frame, did not seem to be able to be reused/recycled as easily.
All in all, this lab was really interesting to me because it was cool opening up a machine and getting to see what exactly made it tick. It was also interesting thinking about how these machines and devices that we see and use so much in our daily lives are actually complex and cleverly composed pieces of machinery under the surface.
