Pulled the trigger on a Moon 861! Hope it pairs well on my Focals

I've had the Moon North on Focal beryllium (Kanta, Sopra, and Utopia) and it's a great match. The Moon is never harsh and everything is controlled well. Warmer than I expected. I have not tried your pre. I've only run with Moon North 891.

My friends that don't like Focal beryllium were not run out of the room with only two setups: the Moon North, and Classe Delta power/pre. Everything is smooth and well balanced and never offensive.

Moon products are great and neutral with no coloration. Like others have mentioned, your preamp will soften the sound. Also, moon and dynaudio pair great together. 

Mac does have a mellow sound, but there’s only so much they can overcome. A few years back, I listened to a lovely system that was all new Macintosh equipment and the newest B&W 80? Speakers. No matter where I sat, no matter how I readjusted the speakers, they hurt my ears at levels in the 75-80 db range.  
Everyone’s hearing is different, but for me, I can’t listen to any metal tweets. That’s why I got rid of my KEF Reference 5’s.  They had aluminum tweeters and midrange drivers.

Simaudio Moon electronics are clear and transparent. Pair them with very revealing speakers and a front end that’s not on the same level and you’re in a world of trouble. 
I would say this is one of the cases when you can build your system around the amplifier. I wouldn’t be surprised if this purchase has a domino effect. We’ll be hearing more from the OP on this. Lol

My speaker is like a Beryllium based speaker, the Yamaha NS5000 (the child of the Be Original Gangster, so to speak). It uses Zylon for the drivers, and it is as detailed as Be.

After hearing the 761 I wanted to get it to pair it with the NS5000, because that would be something special. Great detail but no harshness and also lots of power. I would have rotated the CODA #16 amp and the 761/861 between my 2 system. Luckily, I am tapped out $$ wise and went with a cheaper amp (good enough for now).