Integrated Amp to match with Magico A3

Rhg88, there are a couple of things wrong with your summation about just getting an amp, and not hearing a lot of differences between the two amps.
1: Your Marantz AV 7704 is probably not a great preamp2: The testing conditions ie cables and hooking up to an inexpensive surround sound piece could be a huge limiting factor in hearing a difference between the amps3: Neither the M27 or the SPL S800 may not be great amps4: The M27 and the SPL 800 may both sound similar.
One of the reasons that people are recommending an integrated is the integrated amp will have a suitable preamp stage built in.
The quality of the preamp is very important for these reasons:
1: It is a first stage amplifier that increases the amplitude of the line level signal to match the amplifier2: The quality of the volume regulation preserves time and phase information which can increase of decrease your image.3: The preamp stage may hinder the system's overall level of resolution.
Your test was fine what you should have done would be to substitute a high quality integrated amplifier to see how much better that device would perform.
Dave and TroyAudio Doctor NJ

Audiotroy, thank you for your feedback. As it turns out, we did at one point bypass the AV7704 and use  a much higher quality preamp. Nevertheless, I did not hear a big difference between the two amps.

Are you suggesting that an integrated amp might be better than using the Marantz AV8805 and a power amp? The AV8805 is the top of the line preamp made by Marantz. It has Premium-grade AK4490 32-bit D/A converters and HDAM Discrete Buffer Amplifier Modules.

Audiotroy, I don't quite understand what you mean by "The quality of the volume regulation preserves time and phase information which can increase of decrease your image."

If you want to warm up this very analytical speaker I second the occasional suggestion in the thread that the new Pass .8 stuff might well be a good choice.  Their INT-250 (current version) is absolutely awesome although not 100% class A at full power.

....not an integrated......separates....   get the sound you paid for.