Pocket Headphone Amplifier

If it’s too loud, you’re too old.

…older me is wishing it wasn’t so loud though.

This is one of the first circuit boards I’ve made back in the winter of 2006/2007. Back in high school I rode the bus to and from school and to drown out the noise on the bus, I needed more audio power.

Originally I was looking at the CMoy pocket amplifier:

OPA2134PA-CMoy-Headphone-Amplifier-Schematic

I had one issue with the design though, two 9V batteries, stuffed into an Altoids tin, took up a lot of space, and left very little room for the actual circuit board. I searched digikey, looking for an amplifier that would allow me to use just a single battery, and provide at least 1/2W per audio channel. After a bit of searching, I found the TDA2822 and just used the typical application circuit in the datasheet:

tda2822

The only modification I had to make was to replace the 10k pull-down resistors on the inputs, with a dual-gang log pot to give me volume control. After that I designed the PCB using Express PCB at the time, and then using a sharpie, I drew the CAD design on to the copper clad and etched the board. And here’s how it turned out:

About Me

Current Resume

I’m an Electrical Engineer, currently working for Xerox in Rochester NY. I graduated in 2013 with my Bachelors of Science in Electrical Engineering with an engineering GPA of 3.2/4.0 from the University at Buffalo.

I’ve had an interest in electronics since I was a baby, there’s a video of me where I’m just starring at the camera in awe. As I got older, I did what most engineers did as kids, I took anything and everything apart to understand how it worked. I learned early on, that taking something apart was easy, but putting it back together in full working order, was much more difficult.

In high school I took my first basic electronics class and knew almost immediately this is what I wanted to do for the rest of my life. By the end of the semester I was pointing out mistakes made in my teacher’s drawings, and creating my own circuit boards at home. It was this teacher that saw my passion and how quickly I was able to pick up new concepts, and she encouraged me to take an independent study in the class the following semester and to apply to engineering school.

While at the University at Buffalo, I joined the IEEE student chapter and took up the role as the go to electronics expert. Students from the club and across the hall in the electronics lab would come to me looking for my help to debug their circuits or to bounce ideas off of for a new project, as well as laying out circuit boards, or teaching them how to design and lay out a board. While being a full time student, and active in IEEE, I was still working 20 hours a week, initially at a Deli in my hometown, but senior year I became a Student Assistant in the Electronics Laboratory helping junior level students build and debug circuits as well as the school’s IT department running ethernet lines, installing and repairing TVs and security cameras.

After graduating in 2013, I started working at Xerox in Rochester NY as a Junior Electrical Engineer in the Specialty Sensors group, where I currently work. My main responsibilities involve consulting with other groups with applications of our sensors, designing test boxes for senor validation, creating GUIs to display prints as they come out of the machine.