Rotel RA-1570 to Ayre AX-7e

I would focus on the main speakers first......

The tape out is a fixed line-level output, so the downstream amp will have to be an integrated or you'll need a pre.

Biwired from the Ayre terminals to Vandersteen is a bit tricky (I have the AX-5 Twenty / 3A Sigs) but doable. It's actually recommended in the 3A Sig manual to biwire this way anyway,

I agree the Ayre is a major step up. My dealer let me borrow it while the AX-5 was back in Boulder getting the Twenty update. I was very impressed.

No matter the price, Ayre seems to make top notch gear.

yage, thanks I have an old integrated to use as long as turning on tape out doesn’t interrupt the AX-7 output to main.

Can I put both spades under the speaker connection or would I have to re-terminate to have a single upstream spade?

You can double up on the amp end with no problems. If I'm having new cables made, I do have them terminate both pairs at the amp end. It does make it easier, but you can do it either way. Also, make sure you use 1/4 inch spade connectors. Anything bigger won't fit in the barrier strip.