Tube Amp & Preamp for ML Summits?

I have not heard the Summits but am familiar the Martin Logan sound.
Summits have a powered sub. They xover @270hz.
You are in a biamped situation. You are using CD which has a higher output than phono. This means you can go for nuance over raw power.
I was just reading a review of the ASR Emitter on Audiogon which is available in Europe for a reasonable price.An integrated is a serious consideration. IMO preamp or linestage is not necessary for CD. You might also try the Rowland Research integrated. You might want to try some tube integrateds also.
My GNS modified ARC-SP14 and Moscode 401hr comes in at $7k which you might also want to consider. Mine is very neutral while others prefer a sweeter sound.

I talked to VTL about a ST-150. They stated they have tried that amp with the Summits and recomended something with more power. Unfortunatly the Summits dip to 0.7 ohms at times.

if you are willing to spend a bit more, you could consider the wolcott stereo amp. it has an interesting feature, a variable damping factor.

i heard the amp drive a pair of mg 3.6s .

you should have no problem with the summits.

The Wolcotts interest me but they don't come up used very often.

Definitely consider tubes- for some reason the Summits are bit easier on tubes than some of the other ML models (even our M-60 drives them). Tubes and ESLs are the tradition since the 1950s- its the right thing to do. Above all have fun!