Mix this wave: DIY audio mixer

I'm working in the backstage of concerts of our local choir. We have an intercom system, it's based on the Clear Com party line system, but that's a story for another time.

My issue is that I need to hear the audio from my computer and the audio from the intercom, and I guess that my phone would be a nice idea too. I didn't want something complicated like pan control / EQs.

So to recap, I need:

• 3 Stereo inputs with individual volume control
• 1 Output with amplified output for my headphones

It's been a while since I did some manual soldering on a proto board, and I wanted to avoid waiting 2 weeks for a PCB. So, I went to Farrell and Amazon and ordered a few things:

• 3x 10kOhm Log potentiometers
• DC Input jacks
• PAM8403 Amplifier boards
• 4x 6.35 mm TRS Jacks

Schematic

The schematic is heavily inspired by this project https://www.sonelec-musique.com/electronique_realisations_melangeur_audio_002.html , but with the PAM8403 replacing the op amp.

Soldering

And now I remember why I design pcb instead of manually soldering them.

Case

Assembly

Adding jack connectors

Adding power connector

Placing the PCB

Final photos

Final thoughts

Overall happy with this, not the greatest sound quality, especially because the PAM8403 isn't designed for headphones but it works.

CommentsShortcut to: Comments

Want to chat about this article? Just post a message down here. Chat is powered by giscus and all discussions can be found here: TheStaticTurtle/blog-comments