Yeah, it's just through the headphone jack. There are some filters on the Sony but I'm not using any intentionally (maybe there's some default ones that can't be turned off?). I don't know exactly why it works but, to my ears, this frankenstein setup has really impressed. And, I agree, I don't think the Sony has a lot of power coming through the jack but it's doing something good... I just don't know what. I thought it was just the extra juice at first but what you're saying makes a lot of sense. The open mod is also fantastic. Id highly recommend it.