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TI’s PCM2704 based USB sound card

Hey! It has passed a really long time since my last post but I have been really busy at work in this last months. For a long time that I wanted to make a really simple USB external sound card. The reason for this is that i’m using my KRK Rockit 5 reference monitors with a crapy built in motherboard sound card. The connections are only the ones that come within the main board, in the back of the computer, and if that wasn’t enough i also have noise from the computer when nothing is playing which is terrible.

I have searched for some simple chips that could make me the job and I found TI’s PCM2740. It’s a single ended USB audio interface with analog and digital output.

I have followed the application suggestion that came with the datasheet and tested everything on a breadboard first and then i passed the circuit to a prototyping board to fit in a really small box with left and right output plugs.

This is the result:

Guess what… it sounds awesome! Great sound quality with absolutely no noise at all. Now i have to finish the box, make a an open for the USB plug and that’s it!