Alright, this is my first post but I have read some stuff on here before. I'm not very knowledgeable about pedals and stuff so help me out here.. I've had this pedal for about 2 and a half years, and it had worked fine pretty much the whole time. Around Christmas, I got a Nano Big Muff and I didn't have enough patch cables, and I was too lazy to get one, nor did i need it, so I took the OS-2 out and replaced it with the Nano Big Muff. Recently I plugged it back in because I finally got some patch cables, and noticed this slight hiss, even when it's not on. Of course, when I turn it on, it gets way louder, and when I turn my Big Muff on, it makes it louder too. So matter what, I get this hiss I've tried changing the settings on the pedal, and it will reduce it some, but not enough. I've tested, it is definitely this pedal. I've tried using a battery instead of a 9v adapter, didn't work. What is this, and what can I do about it?