Best bang for buck integrated amp for $500

Thanks for sharing. I would say you are fortunate regarding your noise floor with the Brio. When I contacted Rega, the higher noise floor was a known issue due to the compact size of unit and the only fix was to send the unit to an authorized dealer to perform an adjustment. The adjustment was said to reduce the noise floor but also reduce sound quality as I believe they said they would be reducing the bias. 

I want to hear the NAD D3045 in my system. I have the NAD D3020 V2 in my family room. It was chosen for its size, looks, and features, but it is very meaty sounding and avoids the typical pitfalls of Class D amps under $1000.   

I owned the Rega Brio R.

1. High noise floor so a poor choice for a desk unless you don't mind tweeter hiss when nothing is playing.

2.  Upper mids/lower treble are a bit boosted...giving it a fun and lively sound (toes tapping). Tone/timbre is very good. 

3. Treble is a bit coarse and unrefined, even for a $1000 amp.

4. A great value at UK prices...600 pounds 

Creek 4330R is a great budget integrated for under $500. Same with Audio Refinement Complete integrated. 

Former owner of many compact amps. Here is my compact amp ranking.

1. Burson Funk with Vivid OP amp upgrade - Great bass, warmth, and clarity. This amp is a unicorn.
2. Rega Brio R - Exciting forward sound, unrefined treble, high noise floor, good tone...enjoyable. 
3. Emotiva Bass X 100 - Great build and power for the money. Average across the board for sound...pretty neutral sounding. Brio R has better tone and is just more engaging.   
4. Audioengine N22 - Good mids and pleasant treble. weak bass. warmer timbre. sound lacks dimension, body, and bite.
5. Parasound Zamp V.3 - Tonally cool. Felt like much less than 45 watts. Bad harmonics. 
6. Ice Power 125ASX2 - Sounded like bad Class D. Great bass and bass grip. Mids and treble were very unnatural. thin, cool, dry sounding amp. Would be good for home theatre. 

The Burson took a price hike to 799? A review stated priced from $544, that’s quite a recent hike unless I’m missing something?

$544 is without the OP Amp upgrade or aluminum stand. $744 is fully loaded if you buy from Burson direct. 

Yes no DAC or variable outputs. I hi level connect a REL.