AV Pre/Processor vs 2 Channel Pre-Amp - Sound Quality

Unless you really care a lot about higher quality surround processing and have very good/expensive surround and center speakers, I'd use a decent AVR for processing and driving those channels.  Buying a prepro that significantly betters a decent AVR for processing along with the added amplification you'd need to buy would be a huge added expense.  But if surround music/movies are that important to you and you have the speakers that can benefit from it, it can be a perfectly justifiable purchase. 

Thanks Eric and Soix.

Soix you were helping me on my other similar thread, but then I got curious how much of a sound difference there would be.

As you know, for my basement theater I just bought a current model Marantz processor and Anthem 7 channel amp. 

For the upstairs TV where I have just a 2.1 system but with my nice Monitor Golds I want to listen to music too. As you may recall I have a Pioneer Elite receiver and am thinking about buying an atoll 2 channel amp. I had gone back and forth between a 2 and 5 channel to biamp remember?

So this thread picks up where the other left off. Do I upgrade my pioneer receiver to another Marantz Processor, or do I keep the pioneer and buy a preamp to o between the Pioneer Elite and 2 channel amp. 

Again, for anybody else reading this, I DO NOT want an integrated amp because I have not found an Integrated Amp with HT Bypass that also has bass control. If I buy a preamp with ht Bypass like the Atoll, I could connect that to my Pioneer Receiver. Then I connect the atoll preamp to my subwoofer and use the dial on it for bass management. Why do I need bass management you may be asking? Because I run a 2.1 system and I don’t want the full signal going to my bookshelves because thy distort. Then I would connect my amp to my subwoofer high level outs, and finall to my bookshelf. 

If the Atoll preamp is not going to sound any better than buying another Marantz AV Processor, then I will simply replace the Pioneer Elite with another Marantz 7704 l. 

What subwoofer do you have, and what are your sources for music and movies?

@craigert

For your upstairs tv 2.1 where you only have 2.1 setup, why bother buying an AV receiver or AV pre pro + power amp? Just get a good quality stereo integrated amp with HDMI inputs that can also do bass management. I’m sure you listen to quite a bit of music too in this room.

The Classe Sigma 2200i stereo integrated amp has HDMI inputs and bass management and a subwoofer out. It supports 4k pass through. It has manual PEQ. It sounded really good and has tons of power. But the Classe Sigma 2200i will digitize its analog audio inputs. This is a direct digital amplifier. For your music sources I would highly recommend using its USB DAC input, and for your video or AV sources just use HDMI inputs. 
I'm assuming you have some AV or video sources in this TV room otherwise there's no point of having a TV.