My own guitar amplifier – electronics internship final project
Field report Lucca Wirz, trainee design engineer
As part of my training to become a design engineer, I did a three-week internship in our hardware department. The internship was intended to teach me the basics of electronics and typical practical skills, such as using different electronic components and soldering. At the end of my internship, I was free to evaluate and independently undertake a project on a topic of my choice.
Being a guitar player for the past seven years and passionate about old guitar amplifiers, I decided to build an old tube amp myself. I opted for a replica of the Marshall JCM 800 2204, which came out in 1981. Along with the JCM 800 2203, this was one of the first Marshall guitar amps that enabled players to control distortion separately from the master volume.
I ordered a DIY kit from the USA, containing all the necessary parts for the amp. I tackled the mechanical assembly first, followed by the wiring inside the amp. For this part, I had to make extra sure that I didn't make any errors, because an amplifier can deliver up to 500 volts of energy. To finish off, I made several smaller adjustments, such as exchanging a faulty capacitor in the pre-amp section and setting the bias current for the output stage (no-load currents).
I certainly enjoyed the internship. Not only did I receive insights in the field of electronics, it was also a very hands-on experience. I especially enjoyed the final project, as it gave me a better understanding of analogue technology. For me, the greatest challenge was the complexity of the amplifier. However, thanks to the skills I learned in electronics and the support I received from the hardware team, I was able to complete the project successfully.