I hear Parasound is much better quality sound then Rotel

Um, no. I had a Parasound, now have a Rotel. Both very good amps, built like a tank. Who told you this?

No; not in general.

The more expensive Parasound gear is very good (and very expensive); the A21 sounds very good IMO; the A23 does not (for example). I tried the A23 at home for a week and sent it back; I thought it sucked.

Rotel makes some very good components, and at comparable price points would probably give you more satisfaction based on my experience.

Every price range has some winners and losers, and there are also good integrated amplifiers from Creek and Musical Fidelity that are great-sounding for the money in the under-$2000 range.

Tell us what price range you want to compare within, and it will be easier to be specific.

Which "GEAR" are you looking at in particular...???

Amps, pre-amps, both.... Hows about you narrow it down to what it is your after, as your topic is extremely broad in nature, so's we can better help you sir...

What are the schematic differences between the A21 and the A23 that would account for these differences in sound quality you heard?

Used to have (old) HCA-500 and (newer) A23. Liked both, but sold both and went with an integrated amp for one system and an AVR for my TV setup.

Keyboardcat, you've been bouncing around asking a bunch of questions including stuff at goodwill. What do you have, what do you need, and how much can you spend?

Reviews are completely worthless in audio electronics. Never judge anything by a sonic review. Everyone hears differently and everyone likes different things. You'll actually have to go hear the units you are interested in and pick from there. Parasound and rotel both make good gear, you'd be fine picking either brand. Thats about the only useful info I can give. Lets your ears decide or find a place with a 30 day return policy and try a few out in your own home.

you've noticed...

edit: dear me, there's some "interesting" creative writing at that amazon link....

I would not say Parasound is much better if any then Rotel anything. They both make quality gear on all levels but to say that it's much better I simply don't agree.
I have Installed countless Rotel and Parasound amps , pre's ,receivers , 2 channel , theater systems , Tuners which I have always found quality in both companies.
Unless you can listen to both said amps you wish to consider or all gear of those brands for that matter with the speakers you want to power , then there is no clear choice here.

On a side note Rotel everything can handle 4 ohm loads with ease. Even their 75 watt receivers and 50 watt amps. Same goes for Parasound , no concern with 4 ohm loads. Only concern would be how much power will be required to power unsaid speakers in unsaid room.

Yep.

Plus, Keyboardcat, why separates instead of an AVR?

Random reviews can be entertaining/useful, but it seems you may want to nail down the fundamentals of what you want.

BTW, the answer to your question is "no."

I am sure the other is nice too but I really love my Parasound A51!

One of my friends has a parasound amp and thought it sounded great. Love his set up!

I've had both Rotel and Parasound amps. The Parasound was a multichannel halo and the Rotel a 1075. I liked the sound of the Parasound better. My preference though is NAD.