Focal 1028+Mcintosh MC275

Sterophile measured and reviewed the Electra 1037, so the generation prior and the larger speaker. I’m guessing the measurements are similar but don’t know. Anyway John states that they will sounds tipped up when using tube amps. https://www.stereophile.com/content/focal-electra-1037-be-loudspeaker-measurements

So just be careful you don’t get the opposite effect you are looking for. 

Mac C8 tube pre might be safer with a solid state amp. $4500 I think. 

https://www.mcintoshlabs.com/products/preamplifiers/C8

The 275 is a superb amp.  It will drive anything. It’s super smooth and has plenary of bottom end weight.  It’s also not as colored as other amps for this period.  (I’m thinking marantz 8, which is warmer on the top)
I’ve never heard a bad Focal speaker.  You should be just fine.  They should sound wonderful together.