Onkyo TX-SR803 with MMGs - Amp upgrade YES or NO


I have an Onkyo TX-SR803 connected to a pair of MMGs. The AVR is 4 ohm stable and can easily drive the maggies.
It is a $1000 AV receiver. The sound quality is fantastic. Even when MMG is running as full range in 2 channel stereo, there is no distortion or going to shut off the amp at loud volume but most of the time my listening habits is Moderate to high (75-85 dB), so I’m not going to drive the MMGs hard.

Also, I am using a powered subwoofer with the maggies in a 2.1 setup, crossovered @ 80Hz, so it is important the amplifier has LFE output along bass management and many stand alone stereo amps or power amps do not have this feature except all AV receivers. I don't know any integrated 2 channel amp that has this feature with build-in DAC.

So I am using the build-in DAC (192khz / 24 bit) in Onkyo for 2 channel playback, this way there is no signal loss through analog cable from CD player to amp as well.

That's why I'm considering to get perhaps a better sounding (more audiophile) AV receiver (Marantz, ARCAM, Cambridge Audio, Harman Kardon) instead of a 2 channel integrated amp or separates.

Other option could be a 2 channel power amp connecting into the Onkyo 803 act as a preamp, but still missing the bass management for 2.1 setup and the DACs which I’m using now.

I read a lot about the MMGs that a good two channel, high-current amp that is around 200+ watts/channel @ 4 ohms will help the Maggies open up even more. On the other hand some people drive the MMGs with valve amp @25 watts/channel and reported about great sound with their MMGs. More power is better that’s maybe right, but my MMGs run in a 2.1 setup crossovered @80Hz, so the amp do not need a lot of power to reproduce low frequencies. What is this case, do I still need a lot of power when the load @80Hz goes to subwoofer?

I am aware of good used amps they can let the MMGs sing like:

Adcom GFA-535, 545, or 555, Emotiva UPA-2, Classe DR8, NAD C370, Wyred 4…etc.

Generally, I wonder if I get !AUDIBLE! better clarity, soundstage, details, and more audiophile sonic quality with one of the amps above over Onkyo 803 in a 2.1 setup where the powered sub will do the most work, or it's going to be the same level or even worse (maybe worse because missing the bass management and DACs??)

The big question is, is the effort worth it or not audible?

Thank you guys for help and good advice.
thxbest
It's more expensive to integrate 2 channel into a theatre system, than it is to just do 2 systems. The main reason for that is that the HT gear is the bottleneck. You need it out of the way, but you need to use it if you have nothing else. And that's the problem.

Sometimes you have to get creative, or use less common solutions. Start with the bass. You may already be in good shape. Is the lfe input on your sub filtered, or not? If its filtered, you can run a regular line level signal to it and the sub's internal xover will do the job, and that's it. If not, you can use an external xover to get signal to your subs. Doing it this way will allow you to get signal to your MMG's without having the signal go through a processor. That's a really big deal if you want good 2 channel sound. Here's a link to a really nice, low cost xover. Would you be OK with it?

http://www.guitarcenter.com/Behringer/CX3400-Super-X-Pro-Crossover-182464.gc
The LFE on the sub is filtered, so I don't need an external xover for the sub.

Should run a regular line level signal to the sub from line out of a CD player?

How about DAC as I would like to hook up HTPC and CD player
to the amp in a digital path.
I don't know about your Onkyo, but mine sends the LF signal to the sub when I select "Stereo" mode.
"I don't know about your Onkyo, but mine sends the LF signal to the sub when I select "Stereo" mode."

My Onkyo does the same in "Stereo" mode but it does not send LFE signal in "direct" and "pure" mode.
"08-25-15: Thxbest
"I don't know about your Onkyo, but mine sends the LF signal to the sub when I select "Stereo" mode."

My Onkyo does the same in "Stereo" mode but it does not send LFE signal in "direct" and "pure" mode."

With your system, you don't want to send the lfe to the sub. The signal should only pass through an lfe filter 1 time. Since your sub only has 1 input and its filtered, you send it a standard line level signal. You can use an lfe filter in a HT processor, but you should only do so if you can bypass the one in the sub.