Difference in appearance between the C1000a and the C1000?

I'm a bit confused here. Some pictures that I've seen of the C1000a look the same as the pictures of the C1000. Can someone tell me how to tell the difference in appearance between the C1000a and the C1000? I know that the C1000a is 6.1 and the C1000 is 5.1. I have the user’s manual of the C1000 but can't find a C1000a to compare.

I have the C1000a... and on the back it has a Model# that says C1000... and the a is SCRATCHED into the plate.
I don't think there is any difference in looking at the face. Mine is silkscreened C-1000 on the face, but does have 6 outputs on the back.
Looks to me it was a MOD, rather than a new piece of equipment.
My manual does say C1000a but the box says C1000
Pretty sure the C1000a was a MOD they added, or upgraded to the C1000

Ditto, the only difference I can tell is the "A" model has an extra pair of binding post for the rear center.

Damn Toy Maker, I know this is your forum, but aren't you being a bit of a space hog with that huge bill in your sig.
Now you're realy screwed, posting a bank note on the net. What do you think, this is a free country or something.