Class A multichannel amplifier?

Classe' amplification products are generally considered higher end than the others on your short list. Classe' room EQ adjustability may require a different process which you should check into.

Unless your attempting to assemble a high quality two or multi channel system that will also support HT then quality amplification components may be considered critical by some. If, on the other hand your assembling a primarily HT system the level of quality amplification may not be as critical.

Personally, in a primarily HT system I would forgo some quality in favor of a 7.1 HDMI system. Depending on your viewing habits an HT system can be in use far more that a music only system which would demand far more running time from an amplifier. High quality switching amplifiers are far more efficient for this purpose requiring less wattage, less in standby, less heat, and more economical.

The Arcam AVR600 is a class G amplifier.

Class G
The Class G topology is a modification of another
Class of amplifier (normally Class B or Class AB)
to increase efficiency and reduce power dissipation.
Class G takes advantage of the fact that musical and
voice signals have a high crest factor with most of
the signal content at lower amplitudes. The Class
G topology uses multiple power supplies, operating
from the power rail that provides the optimum
combination of headroom and power dissipation.
Th e Class G topology improves amplifier efficiency
by optimizing the power supply. A Class G device
uses a minimum of two different supply rails. Th e
device operates from the lower supply until output
headroom becomes an issue. At this point the device
switches the output stage to the higher supply
rail. Once the output signal drops below a predetermined
level, the device switches back to the
lower rail. Power dissipation is greatly reduced for
typical musical or voice sources. Figure 3 illustrates
a simplified Class G implementation with a split
supply Class AB output stage.

I am currently using an AVR600 in my home system and have nothing but praise for it. Outstanding sound superior to most anything else I have heard for HT including Classe` and other high end HT receivers.

In 2 channel mode using Dali helicon line of speakers it sounds remarkably good. Although it is difficult to set up a system that sounds good for both HT and 2 channel. This will be a challenge especially with a projector you will need a retractable screen for 2 channel. So unless you need one system to do both which I recommend against I would think the need for Class A amps in a HT are not necessary.

The need for 7.1 seems to be overrated since so few BD discs are actual 7.1 and 95% of the time you will be listening in 5.1 EX. I have to admit there is a huge difference between the 2 and if more discs were supplied in 7.1 I would say spend the extra on the speakers . For now you might consider wiring your room for 7.1 and seeing what happens in the future of these discs if more 7.1 content is released.

Cobaltturbo, I hope the original poster takes our subjective remarks and suggestions for what they are, subjective.

When I suggest going with a 7.1 system I usually mention room size is not an issue and regardless of the quickly growing amount of available 7.1 media that simple 5.1 productions on both disc and broadcast can sound much more surrounding when matrixed through a capable 7.1 system. The LCR somehow become more discrete in locating on screen audio queues than with 5.1. I can't speak of the actual way the matrixing is accomplished other than to say the side channels seem to bridge the left and right channels with the rears widening the screens sound stage and creating a rear that's more peripheral. The effect is amazingly uncanny and far more fun than 5.1. Another variable I can't speak of is just how much the quality of the room correction being used plays into the success of matrixed 7.1.

When auditioning for my current HT I too found the Arcam to provide a very nice audio presentation. Ultimately, I passed on Arcam. When pushed to more realistic volume levels its output became somewhat congested similar to the Integra unit I was replacing. It also lacked a comprehensive automatic time, EQ, and volume balance room correction program in favor of Dolby Volume processing and gain management.

As an owner of an avr600, there is little that is actually better for multichannel. Even in two channel it sounds great. However the Arcam av888 paired with the matching p777 sounds excellent as well. It definitely sounds better, but the only concern I have is the price. It costs more than twice as much as an avr600. I don't think it sounds twice as good. Cost of diminishing returns I'm afraid. I would say it sounds about 20-30% better. When you look at what other pre/pros are available, the av888 is cheaper. I've heard the classe pre/pro (can't remember model). It sounds really good, but didn't hear it side by side with an arcam (different dealer, but same speakers). The classe was more money as well. If I had to pick though I would go the arcam route. Thats just me though.

Another option is to take a look at Butler audio. There is an amp for sale here on this site.