New Parasound A21 VS Mark Levinson #23

Agreed....the Parasound Halo A21 is a great amp especially considering its modest retail price of $2500 new.
One of the best sounding amp in that price range.

Mark Levinson IMO makes outstanding gears, especially their preamps, but priced much higher than the Parasound.
I have never heard that Levinson #23 amp before so can’t really comment on that particular amp.

You can never go wrong with the Halo A21 amp IMO. It’s a steal at $2500 new for the kind of performance you get. It is a phenomenal sounding amp.
I think it will sound good on your B&W 803. Which B&W 803 do you have? 803 D2 or the latest 803 D3?

The flagship stereo power amp from Rotel called the RB-1590 will also sound great on your B&W 803. The Rotel RB-1590 retails for $3k and is huge massive and weighs in over 90 lbs. Rotel & B&W have great synergy together.
But in general IMO the Halo A21 is a better amp than the Rotel RB-1590. But you’ll never know.....the Rotel RB-1590 might pair better with your B&W 803. Who knows?

For your B&W 803 speakers if you’re willing to spend more I would look at the Classe Delta CA-2300 class AB stereo power amp. This amp, along with other Classe Delta series gears, were discontinued last year and nowaday it can be had in used after markets at discounted price. Its original retail price was $7k but since it’s been discontinued you can find a used one for around $4k ish. The Classe CA-2300 is a class AB amp and it will be an excellent match for your B&W 803 especially the latest B&W 803 D3 speakers. They will sound great together. Classe will pair really well with B&W. But again this CA-2300 amp is huge and very heavy weighs in well over 90 lbs.

In my dedicated home theater room my front speakers are the B&W 800 D3 driven by a pair of Classe Delta CAM-600 class AB monoblock amps and they sound terrific together and you couldn’t get any better than that. But of course performance wise and sonically the CAM-600 monoblock amps are step up from the CA-2300.

One thing you should note that the Parasound Halo A21 amp runs kind of hot so I wouldn't put it in a confined rack. The Levinson amps can generally run kinda warm too. However, both the Rotel RB-1590 amp and the Classe CA-2300 amp never run hot no matter how hard you drive them. They run cool the whole time. 

Having personal experience with Parasound A21, I will say that the Parasound sonic signature is definitely on the warm side of things.  It is a very good amp and has a very refined midrange sound, but still on the warm side. 

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Parasound uses excellent parts and components and they have an excellent overall design.  I have found that the one thing that holds back the Parasound is how many fuses it has.  Parasound likes to fuse the heck out of their amplifiers.  The A21 has 5 fuses total.

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You can make the Parasound A21 a world class amp by just investing a little more into fuse upgrade:

1 x Hi-Fi Tuning Supreme LARGE 15A for the back panel main fuse.
4 x Furutech LARGE 10A for the internal post-transformer fuses.
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When using Furutech for all 5 fuses, the sound was still excellent (much better than stock), but was still too warm for me (I lost resolution and attack).  The single Hi-Fi Tuning Supreme silver fuse boosted the speed just enough so that I had excellent attack / resolution / detail.

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However, in your case, with the older 803S that uses the aluminum tweeters and the older kevlar midrange breakup issue, you might want to try out all Furutech first.  400-500 hours of burn-in required for Furutech before you should make a decision.   

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The older kevlar midrange had an issue with break-up which caused distortion in the sound and could come across as too bright/harsh in some systems.  A slightly warmer amp can mask this problem as well as the bright/breakup of the aluminum dome tweeter.

Thank you all for the wonderful advise.very helpful.  I am new to audiophile and just  learning new things everyday. I will go with A21 as it appears solid in every aspect for now. I may need help with fuse upgrade  etc which I may have to request the dealer to help. Thanks again! 

Which B&W 803 do you have? 803 D2 or the latest 803 D3?

Mines is 803 Nautilus

While I agree with the above about the Parasound A21, if the Levinson has had the caps replaced and completely serviced within the past few years, it is hands down a better sounding amp.

I was a Levinson dealer for many years and have owned a bunch of their equipment. I wasn't ever a Parasound dealer, but have owned a lot of their product also, including the A21.

Once you hear a properly working Levinson amp, it's hard to get it out of your head.  They are indeed quite nice, but I agree, that they have their own sonic signature, (just like everything else).

Without knowing the provenance of the Levinson, the A21 is a safer bet.