Lamm LL2 preamp VS First Sound 4.0 MKII preamp

Dear audiogoners , i actually have the thought to connect my lamm ml2's to the mentioned preamps .
My speakers are the kharma 3.2 f + cesb sub 1.0.
Surely the same brand is important, i mean is obvious to set as preamp the ll2 before the ml2's.But from the other side a preamp so pure with step attenuators each for chanel is a challenging idea as the First Sound has got.
Who test the combination lamm ll2 with the ml2's or the ml2.1's and who the combo first sound 4.0 mkii or enen with paramount upgrade or special edition upgrade with the ml2's or ml2,1's?
Are really sonic differences between the 2possibilities?
I can't comment directly on their synergy with the Lamm amp, but I've heard both the FS Dlx Mk2 and the LL2 pre-amps. The First Sound is superior, IMO.
Can't comment on the ML-2, but I have used the LL2 with my ML 1.1s while my Jadis was in the shop. Excellent combination, though a little richer than neutral in the bass. The Lamm has dual volume controls, by the way, though I can't recall if they're stepped attenuators. The Lamm L2 preamp would be a more refined performer in every respect, probably worth the extra money for a used unit, with those amps. There are plenty of other excellent preamps you can use (my Jadis is exceptional with the Lamms), but at this level of performance your personal preference will play more of a role in deciding than any huge differences between the different units.