Can 10W 300B tube amp drive Martin Logan Ascent i?

No it won't is the short and true answer.

I was thinking of getting a YAQIN MS-300C 300B x 2 Vacuum Tube Hi-end Tube Integrated Amplifier which produces 9.5 wpc, available on ebay. I have magnaplanar 1 speakers, the originals 5' high. Their brochure recommends 40 wpc. So, it won't work with my speakers?
I ask because I know nothing about tube amps, but have read that the listed wpc is frequently nonsense. I listen to classical music and jazz.

You`re looking at a disappointing result with this match. This speaker is far too inefficient to work with your amplifier.Low watt SET amps can sound marvelous but only with appropriate speaker compatability.You have to avoid these types of power hungry speakers.

Thanks for athe opinion, Charles1dad. The alternative amp is for me a Yaqin MS-20L with EL34B tubes which delivers 50 wpc. I had heard very good things about the 300B tubes; that's why I was interested in the YAQIN MS-300C 300B. But the EL34B tubes get good reviews too. Musically, is there any reason to prefer one to the other?

Franz456,
The choice of output tube is just simply subjective, there`re too many variables that affect preference. You could have two amps with the same output tube and they could sound radically different.I`ve owned el34,6550/kt88 amps and the best of each breed can be excellent.

My personal favorite type tubes are the DHT(directly heated triode) . When done right the DHT as SET or push-pull has a bit more 'naturalness' and realism of actual instruments and voice(at least to my ears). But that``s just one opinion among many other preferences.The bottom line is the amplifier and speaker have to match properly,thus many different tubes can work in the right situation. For example my speaker is 94db and a 14 ohm load(minimum 10 ohm) this is a wonderful match with my 8 watt 300b amplifier.
Regards,