I'm new to home recording So I have to "under $100" mixer and I connect it to a keyboard "audio out" and to a mic. I set the EQ and the levels and the headphone volume to what I like and notice some "hiss". So I rotate the connectors and hear that there must be some corrosion as it crackles. I get rid of that problem but I still hear hiss. The next thing I do is pull out the input cables from the mic and keyboard. Turns out with the levels set to about 8 or 9 and nothing put headphones plugged into the mixer I can hear hiss in my headphones. The noise must be coming from the op-amps inside the mixer, right? Is this just what I should expect from an under $100 8x2 mixer or is it broken? Yes do have to turn th levels up because my cheap K/B and cheap mic are not giving much signal. If I take the mixer back do is there such a thing as a quiet, low cost mixer? How much do you have to spend to get a decent one?