All of this started when I found a really cool case on AliExpress, the GOF-P01 133.4x55x109mm and it all snowballed from that point. The one thing I actually needed was an audio input switcher so that I didn't have to swap the cables going into my 80s boombox, so I tried bying a ready-made module that in the end never fit into the case so I had to redesign the module to fit - then I added a VU Meter kit, mostly because I think they are really cool and I never had one before.
The first part of this project is therefore the passive audio switch, it allows up to four 3.5mm audio inputs that are switched to one output using relays. The PCB designed for it is the main part of this part, in addition to the documentation needed to actually build the complete unit.
The final part was the VU meter driver board and parts, those I'm using without any modification as the kit I bought on AliExpress (also available on Banggood and ebay) so far seems to work as intended. Just search for 2 Pcs VU Meter Warm Backlight Recording Audio Level Amp With Driver Module, or any combination of those words and you should be able to find one for around 20$. The warm backlight described is actually a good old bulb, so they have a nice glow to them - you can see a video of the completed unit on youtube.com.
Going forward with this build, I'll be assuming you bought the same version of VU meters and case though you can substutute any parts as needed.
I won't be selling these, they're way too much to be making them for someone else. There will be an added project link for ordering the PCBs from PCBWay, but you can use any PCB fabrication company by giving them the contents of the export directory (usually referred to as gerber files).
Follow the links below for build instructions, the BOM and the relevant PCBWay shared projects belonging or associated with this project: