LUXMAN L509X VS M700/C700U

Deltas don't do well with solid state. I had them with tube amplification after been unable to match them with SS for months.
They are moderate efficient speakers buy they need Current to control the multiple drivers design. Stay away from SS if you keep deltas.
Best,

If the OP had started with a Luman SS Pre and wanted to go something to soften the highs, I'd completely agree, go tubes.
However, the OP is starting with an Oppo HA-1 which, IMHO, is awful. If he can listen to that, then going to the Luxman will be a huge improvement across the board.

He _should_ listen.

Also, yeah, I have problems with the Triangle horn tweets, but I wonder now how much of that is placement. Don't toe those in, and make sure you have lots of high frequency absorbers around the room, especially between and behind the speakers, including the floor.

Wow these are excellent conversations 
I actually had heard b&w 804 before the deltas and thetas
Deltas made me crave to go back to hear more music cuz the definition in the music it played 
I heard them with Sqn 150 and then I compared them with M700u 
i
also wanted to see if you all had any comments on 509 vs seperates

Triangles are brand new I will love to live with them for few years 

how was was the base in the Luxman tubes combo?

If you have the budget separates 900 series will outperform all previously mentioned.
Regards

The only amps I can say smokes everything I had owned are Mastersound PF100. Yes best ever up to date in my journey. 
Lifetime investment. 
Smile in your face.
Best,