Both the 7500 and 7700 have a maximum power consumption of 1800 watts in specsheet.
But how can that be ....the 7500 is 200 x 5 and the 7700 is 200 x 7.
should'nt the 7500 use less power ?
Also what do they draw at idle and low output....10 - 40 watts per channel which is where they'll run much of the time ?

There's only so much current that you can draw from a 15A circuit - and that translates into 1800W. I'm not sure about the idle draw but it's likely to be small (most folks use the trigger to shut them down when the system's off). Actual consumption values are going to depend too much on other variables (speaker efficiency, volume and acoustics of listening room, source material, and volume). Actual electrical consumption would probably be in the neighborhood of 3A or 4A in many cases (a conservative guess) even at higher volume levels, and that equates to around 400W or 500W total. That's just a guess, though - you could see cases where you don't draw more than an amp or two, or a system with inefficient speakers in a large room with an aggressive surround mix at reference level could probably sustain 7A or 8A. I've got some numbers in my design notebooks at work from when I tried to estimate the heat load of a multichannel amplifier, but as you can tell there are a ton of variables involved and there's no research data that I've found that provides any support for my estimates.

Thanks gonk
I should'nt have a problem then on a light load 15 amp circuit, I actually plan on drawing from 2 15 amp circuits for my total system.
And I suppose the more channels you use and drive harder the more power the 7500 or 7700 will draw.

Gonk.
I want to bi-amp my Gold i's using 4 of the 5 channels of the 7500, Outlaw told me to use the pca "Y" adapter but that won't allow me to adjust the power to the mid and highs vs the woofer.
I want to adjust the power level going to the woofer seperatly from the mid & tweeter.
Can I do that with the 990 ?

When bi-amping, the only way to adjust the levels of the two signals is externally from the receiver or processor (I'm not aware of any units that include internal level controls that would allow this). That's typically done with gain controls at the amps (controls that are not as common on multichannel amps as on older stereo amps), unless you actively bi-amp (in which case the external crossover network could provide some gain control as well). I'm going to hunt around a bit for an old thread that discussed this very issue, as it included some discussions of the dangers of separately adjusting treble/mid and low frequency levels. Basically, though, the speaker designer based design decisions for the drivers and the crossover network on the inputs getting equal magnitude signals, so altering those levels can have repercussions on the overall frequency response of the speaker. I'll see if I can find that thread.

While looking for the thread that I was thinking of, I came across this thread in which bestbang4thebuck made a really good post on this topic:
Bestbang4thebuck also had a similar post in this thread (which I think was the one I was thinking of).

Ok gonk it sounds like I want to do a passive bi-amp of my speakers. Given that my speakers like lots of power do you think this would be a good way to give them that extra power ?
And would it be better to use a "Y" connector on the unbalanced L&R outputs for running 4 channels or use the L&R balanced outputs + the L&R unbalanced outputs instead ?
Also I think I remember reading somewhere in the manual that the outputs on the 990 have an adjustment of + - 15 db.

Passive bi-amping will give the speakers more power, so if a single channel of the amp by itself won't do it then two should give you the extra you need. I'd run a "Y" connector with the unbalanced outputs so you maintain the same gain (balanced produces a signal that's 3dB higher).

The 990 does have channel calibration controls that allow +/- 15dB of control over each channel. This is necessary with any surround receiver or processor to allow the different speakers in the system to be adjusted to produce the same volume levels. The 990's manual can walk you through both the automatic and manual calibration processes.