Yes, it might be a silly thing to ask but I was wondering if anybody is modding their 990 to pull a little extra performance out of it. Any input appreciated.

thank you

I haven't heard of any 990 mods. In fact, the only Outlaw product I've ever heard of mods for (aside from barend's transformer surgery to allow a 7700 to run natively on a 220V grid) is for the old Model 200 - there was somebody doing a fairly pricey mod that included adding a balanced input (among other things). Now that the 2200 is around and already comes, I don't know if there's much happening there either.

that's what i figured but it couldn't hurt to ask. kinda wish preprocessors were modular so that you could plug newer chips into it as they became available, etc.

There have been a few card-based processors, but the cost to develop the architecture, design the modular components, and cope with the various possible iterations tends to keep the price on those higher than most folks like - it ends up being cheaper to buy something like Outlaw and sell it a few years later to help pay for a newer product than to buy into one of those card-based units and purchase updated cards. Plus you have to trust the manufacturer to come out with updated cards to buy.

The modding community is often very active in modding products like two-channel gear, but it never really has gotten into messing with receivers or surround processors - probably due in part to the sheer complexity of products like that. Analog side changes would typically mean surgery on printed circuit boards (yuck), power supplies in processors are generally designed to be plenty robust for the application, and the digital side is such a complex balancing act of logic that somebody outside the design team is going to have to spend far too much time trying to not break what's already there to make any improvements and still be able to make money off of selling those improvements. DVD players have developed a mod community, but I suspect that got started as region-free hacks and grew to include tweaks like power supply upgrades that wouldn't get too close to the heavy computational portions of the equipment.

Re
I haven't heard of any 990 mods. In fact, the only Outlaw product I've ever heard of mods for (aside from barend's transformer surgery to allow a 7700 to run natively on a 220V grid)

Gonk, this project is still waiting for me...in fact the 1770 played fine with the primaries wired in series and adding an extra toroid with 0-115-230V center tap across the existing primaries, in order to force both 115V toroids to get the correct 115V (since they turned out not to be equal).
The sound was very very good when coupled to the 990 by balanced cables, and although my current setup (Arcam FMJ P7 final and FMJ AV8 processor, plus Linn Unidisk 1.1 player) sounds very good I still think 7 x 200W is better than 7 x 150W.
When I had it hooked up (the 990) I was amazed by its neutrality, and I'm still curious how this compares to the Arcams...
Now the only thing is the WEIGHT !
55 KG of final amp (with the extra toroid) needs to remain stationary, so I am thinking of a sort of duct to carry the 7 input cables and another one for the speakers...).