Hi all, I've been using some AKG headphones while watching TV and using the exercise bike very early in the mornings, but I want to switch to my in-ear headphones instead. I already had an extension cable going from the TV to the AKG headphones (small to large adaptor at headphones and large to small adaptor at TV), but I needed a different type of extension cable (and a longer one) in order to use the in-ear headphones. So I bought a cable with a large jack at the TV end and a small socket at the headphone end, using a large to small adaptor at the TV end. Yes I am aware that a small to small extension cable would have worked with both sets of headphones, but the new extension is bought now! The issue I'm having is that I am getting a constant hissing sound when using the in-ear headphones, be it through the extension cable or direct to the TV (which I tried just to test and compare). There is also a hissing sound if I use the in-ear headphones via the surround sound amplifier, although the hissing is less prominent (but I'd rather go via the TV if possible because it's a lot more convenient). When using the AKG headphones through the TV or amp there is no hissing at all, and I know that there is nothing wrong with the in-ear headphones because I use them every day with my phone. Does anyone know what the cause of the issue might be? I'm no expert but could it be something to do with resistance? And if so is there a workaround?