with a much higher DF-that is, with a relatively high impedance, like many tube amps have.Damping factor has little to do with how much bass you get! - but it has a lot to do with how much distortion you get with that bass. IOW low damping factor does not translate to lack of bass! Nelson Pass has an interesting article on one of his sites regarding this fact and demonstrated it at the RMAF using a set of open baffle loudspeakers and his amps a few years ago.Damping factors of probably at least 20, which is probably 10 times higher than the Atmasphere S30. No wonder my friend’s friend got no bass from the S30 driving his 57s.
In the case of a Quad 57, the S-30 has a much higher damping factor in the bass simply due to the impedance of the speaker.
Its far more likely that your friend simply hooked the S-30 up out of phase. The problem you run into with tube amps on ESLs in general is not that they don't make bass, its whether or not the amp can make highs on the speaker due to the low impedance at high frequencies.
The J2 does look like an amp that might do the job. When using a solid state amp on the Quad 57s, due to the impedance curve an amplifier that does not use loop negative feedback is likely able to do a better job than one that does use feedback.