Here’s the details:
It’s a ‘prototype’ of a passive Mini Mixer for use with 2 sources like iPhones/Pods/Pads and other MP3 players, NDS, Gameboys and everything else you can connect a RCA or jack cable to. It has 2 mini jack inputs for the sources, 1 output you can switch between RCA and mini jack (with the red lever switch) and 1 mini jack as headphone output.
The output was designed this way to prevent the user from connecting both outputs at the same time which could lower the output volume. This might be nonsense but I built it like that because i had some spare RCA jacks and thought it looked cool.
Each channel has a separate volume knob (the two silver ones on the prototype) and there’s a switch (the black ones left and right of the black headphone volume knob) for each channel to select it’s ‘mode’ (you can set each switch to output, mute or headphone).
The headphone out has it’s own volume knob (the above mentioned black knob). One limitation introduced by the passive design is that you can’t set a channel to output AND headphone at the same time, i thought that would lower the signal to much and would be audible in the mix. You’ll just have to change your mixing technique a little bit which isn’t much of a problem.
Started as a fun little project, turned into a hassle when I had to solder with everything already mounted in the enclosure but in the end int worked fine.