Cambridge Audio Evo 150 vs Hifi Rose RS520

If your list is somehow already restricted to just these two options, then it’s CAMBRIDGE as a likely preferred synergy match to your speakers IMO.

https://www.theabsolutesound.com/articles/cambridge-audio-evo-150-streaming-integrated-amplifier/

BUT …. buying either one purely blind is a helluva risk of a synergy mismatch regardless, that I would not personally undertake. Make the effort to audition them personally ….the final accountability will be yours alone.

CAUTION: Dont get swayed by marketing puffery for specs touting WPC as any kind if a magic silver bullet on amp power.

Audio - amps speakers 

(1) The philosophy is clear. An affordable speaker with decent amplification (and source) makes moresense than an expensive speaker with a cheap amp and source.

(2) Amplifier power ratings

Another word on power: If your speakers are demanding to drive you’ll need a suitably muscular amplifier to support them….sure.

BUT …it’s current (amps) that is the key…. Not WPC. WPC specs alone are meaningless. Don’t look only at the headline power figure - see what happens when the impedance drops to four ohms. If the number nearly doubles, then your amplifier has good current delivery and will be capable of driving more demanding speakers.

I appreciate the insights akg_ca. Never heard about the amperage being key. 

I went with the Evo 150 from Crutchfield which has a good return policy that helped mitigate risk.  It does it all and sounds great. Enough power to go to 90db+ with most speakers with wonderful detail and dynamics. That’s about as loud as one should go normally in order to safeguard one’s ears. I use mine mainly with large Ohm Walsh and kef ls50 meta.

I've never heard the Cambridge, but have sold several of the RS520s, and think they are quite good.  The GAN based amps in the 520 sound very nice, and should be a fun match with your Revels. 
You likely have seen this, but the Stereophile review of the 520 pretty much sums up the unit nicely (small quirks and all.....):

https://www.stereophile.com/content/hifi-rose-rs520-streaming-integrated-amplifier-page-2