mcintosh c2600 and ma6600 question

As far as I can tell, you wouldn't gain much.  The MA6600 doesn't seem to offer an external processor loop.  That's what would disconnect the 6600 preamp section from its power amp and allow you to use all the benefits of the 2600.  You can use the fixed output of the 2600 into the server input of the 6000 if you wish, but that just washes the tubed output through the SS preamp section.  Patience may be more appropriate.

1. Yes

2. See #3

3. You will need to remove the jumpers between Output 1 and PWR AMP on the MA6600. Then use a cable to connect the output of the C2600 to PWR AMP on the MA6600. All sources will need to be disconnected from the MA6600 and connected to the C2600. This will use only the power section of the MA6600 with the C2600. All controls of the MA6600 will be useless except for the power button. This uses the C2600 as the preamp and bypasses the preamp section of the MA6600. Then just use the C2600 controls like you were using the controls on the MA6600. Sonic benefits, absolutely. 3rd component, actually no, just using a different preamp.

4.No

5.You can just try it to see how it sounds.

***Make sure you store the jumpers in a safe place. They will have to be reattached to use the MA6600 as a stand alone integrated amp.

My mistake; @tls49 is correct.  There are indeed jumpers between the power amp and output 1 jacks.  The rear panel photo I looked at yesterday wasn't clear enough to see that.  No substitute for checking the original manual information.  Apologies!

Regardless, have fun with your new 2600 and tell us how you like it.  It's supposed to be quite the piece.