Class A multichannel amplifier?


I just bought a 5.1 speaker system consisting of Coincident Technology Triumph Rxtreme II speakers with the front left and right speakers being supported by their passive subwoofers (which also act as speaker stands) and the left and right rear speakers being supported by the Coincident Technology speaker stands.

As these are high efficiency speakers I was wondering if there was suitable multi-channel Class A amplification, or at least a 3-channel and stereo amp that would be a good fit.

I will also need a high quality AV processor from Classe, Anthem, Arcam, Integra, etc and would like to hear any recommendations.

I just bought a Panasonic 65" plasma and an OPPO BDP-93, so any advice would be most welcome.

Greg
allchemie
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.
>I realize that a Class A multichannel amp would put out a
>lot of heat. Maybe I should consider a Class A/B with high
>bias into Class A.

You just described the Pass Labs X5 or X3 multi-ch. amps. They are no longer made but a decent piece of equipment for HT used. It works real well for HT. Still, I'd use class-A for the mains and a powered SW.
Cobaltturbo-

I realize that the Arcam is Class G, but it is highly biased to run in Class A for the first 20 watts. I believe that information is on Arcam's website and if it isn't it is definitely on the review of the Arcam AVR600 by Peter Moncrief at the IAR80 review page and at Widescreen website review.

Most manufacturers only use a single voltage rail, but the higher and lower voltage rails on the Arcam AVR600 classify it as a Class G device. But Arcam chose to bias the first 20 watts (where the vast majority of music resides) because it sounds far better than a regular A/B bias, which doesn't follow the full wave pattern as Class A does. The use of Class G (higher and lower voltage rails)by Arcam allowed them to have a considerable heat savings which permitted them the luxury of using those savings for a large amount of Class A biasing (which emits far more heat than the classic A/B that is used in most receivers).
But Arcam's brilliant engineering allowed them to use this tremendous heat savings with the addition of Class A.

All other receiver manufacturers use a single voltage rail system, which must be on all the time. Arcam employs a higher and lower voltage rail (Class G), with the lower rail using far less power and emitting far less heat than the higher voltage rail. Since most music doesn't require the higher voltage rails, Arcam is able to utilize the substantial heat and power savings by biasing heavily into Class A.

I have bought a Panasonic V25 65" Plasma which made me have to place my sofa at the rear wall. This means I must employ a 5.1 system, as opposed to being able to use a 7.1.

Greg