I recently purchased the USA Spec IPOD adapter for my 06 Accord. I notice a annoying hissing when the volume goes over 20. Connection issue? I have the factory stereo in there but CD's and the Radio don't produce the same hiss. Any advice?

 

Mine did that with the PIE AUX interface. I was totally dissatisfied with the quality and volume, so I just replaced my headunit and I never looked back. I don't have any experience with any other interfaces but I wouldn't be surprised if it was all of them. I would try using a different set of RCAs and double check your connections, buts its probably just the interface making noise like mine did. I hope you can figure it out, good luck!

EDIT: Just noticed it was the ipod specific adapter, so there aren't any RCAs. I would try and swap any cable you can, although chances are you can't and it won't make a difference anyway.