Denon 2900 mods. Newbie needs help.

[ggante]

I've read all the posts I could find on modifying the 2900 and I have a few questions I would like to clear up.
My background in electronics is minimal. I've been modifying Hafler amps since the early 80's. I performed a full POOGE mod on my 1st DH-200 and I still use that amp to this day.
This is my 1st attempt at modifying a CD player. I performed most of the powersupply mods using info culled from these posts and am pleased with the results. Better focus, tighter bass, etc.
My questions have to do with the audio board mods. I have 3 players and want to mod 2 of them. I need to know just what mods affect 2 channel playback and which mods are needed to enhance multi channel playback (SACD). I use the 6 chan. analog outs to my B&K Ref 50 Pre/Amp/Processor analog inputs.
Does upgrading the two OP amps (op275's) to OP627's only improve 2 channel performance or does it also affect multi channel? Which are the output capacitors for the surround channels?
It seems all the mods I read about are for 2 channel only.
I'm not interested in video performance at all and plan to leave the video boards out.

Thanks for any help.
Dan G. Hamburg, NY