Humming on new Conrad Johnson MF2200

I just received a "new" CJ ML2200. I hooked it up to my Luxman R117 receiver (for now) and it hums like mad. Is this normal (I hope not), do I need to change something, or is the amp defective?
The reason it hums is becaues it doesn't know the words.
How can MF2200 be new if it has been discontinued for years? I don't understande how you connected the amp to your receiver? Does the Luxman have the pre-outs? Is the hum in both speakers?
Hi Eugkim; unhook your amp from everything and plug it into the wall, if it hums it maybe a mechanical hum-- check to see if transformer is well secured. If it still hums it is probably DC "leakage" into your power lines-- nothing you can do about this except complain to power co. Next, plug amp back into your receiver-- you'll know if this is the source of the hum-- it's probably a feedback loop between amp and pre-amp. Try "floating the ground" between amp and receiver by using a two prong cheater plug-- not really recommended, but often used to reduce ground loop hum. Also try same with your receiver. If when all this is hooked up and your speakers hum, there is something wrong with the amp (if the receiver is not connected), and something wrong with the receiver if it's in the chain. Just use a logical process of elimination to isolate the problem. Most likely it's a ground loop problem. Good Luck. Craig
Did you get it from Northampton Audio/Spearit Sound ?? To answer Jack, they made a special purchase of CJ's left over stock of the older MF amplifiers. So they have new ones including the 2300, 2200 and 2100. If you got it there, call Dick Moulding, he will surely help.
Thanks for the responses - especially Craig. The amp does have a barely perceptible hum by itself, but the noise through the speakers stopped when I used the cheater plug. Incidently, I bought it used - hence the "new" in my post.