Mark Levinson Amplifier Hiss

I am auditioning a Levinson ML-9. I do not have a low noise floor by any means. I am using the ML-9 pre with the amp. When I have the amp idling and no source either playing or even on, I have a hiss coming from the speakers.

As I go through the volume range, the hiss disappears greatly around 2 and to a great, but lesser extent, around 5 (12 o'clock) on the volume knob. I have tried using a 2 prong plug on the pre and the amp, but no change in the hiss. I have also shut down the sub, but have not removed it from the audio chain.

I have hooked up my CDP with variable out to the amp and the noise floor has lowered, but is still noticable.

So, as it stands, I am out of ideas on how to remove the hiss. As you close in on the speakers, the hiss is noticeable. Even as you listen to quiet passages, you can hear it.

What can I do, or is the amp just noisy?

Teanks,