Why is my 3DS doing this?

[Petzbreeder]

I've been having an issue with my Brally VC 3DS recently. Every time I try to record anything, the picture looks ok but the sound is a little messed up.

See for yourself.

I'm using a wire plugged into the headphone socket, with the red and white ends plugged into an audio mixer to record the sound. I think it might be broken or something. Where can I get another one to replace it?

I've sort of fixed the problem now, it was my mixer that was causing the problem the whole time. I'll have to get it fixed or replaced at some point.