I just received my new to me MC 2105. Hooked it up and it has a hiss at full Gain in both channels. I called the vendor who sold me the amp and was told to turn the gain down to 12 o'clock. It still has hiss at the 12 o'clock position although lower. I have no hiss with my MC240 even at full gain. Is this normal with McIntosh solid state amps? Does the MC2505 have hiss as well? I don't remember a hiss with my old SAE amp.