The last time I compared them directly was with VR-9s. What they have in common is that they both avoid masking lower level musical lines while louder ones play. My test for this is Stanslav Richter playing the adagio in Liszt Piano Concerto No 1 (Philips). Where they diverge most is in the background. The Lamm Hybrids have dark backgrounds. The 2.2 is silky black and the 1.2R is velvety black. The M1s are clear. I attribute this to the second harmonics of the respective units and the tubes employed. As voltage swings widen the effect on the music material continues. Some might recall that I switched to first Mullard CV2492 then Valvos then Amperex Blue tips on 2.2s to get closer to the sound of stock 1.2Rs and Tele red tipped 1.2Rs with some success. I ultimately went with 2.2s because they dealt with the sealed mid bass units of the VR-9s better simply because of more available headroom given my large room and greater than usual listening distance (12ft vs the more typical 9ft for these speakers). At first the velvety background seems fuller but upon extended listening, in my case I found that part of that was a rounding of the nidbass perhaps due to under damping. As bass extends downward and hands over to the built in subs one notices some smearing on LF ambient cues that affect the portrayal of hall size. On the plus side the added harmonics accentuate the timbre of wood instruments and their resonances as well as middle registers on voices. This makes the 1.2s very appealing in that the sound while high in resolution is also both comforting and forgiving albeit they lack the transparency of their SET stablemates while delivering a similar tonal contour.
The clear or colorless backgrounds of the M1 understandable affect the musical material as well. With the first switch to the M1 simply using the ear test for level matching the sound seems hard and thin. Whip the Phonic or RTA app out and one surprisingly finds that SPL is way up. Not sure why this is in terms of distortion spectra (lower odd order too perhaps?) but dropping it down to matched levels (my pink noise calibration point is always 85dB w/c is a common studio standard) the hardness is now gone and they are now sweet and pure for the same musical material most probably monitored at or close to the said standard. In any case the effect is that of expanded spatiality both between elements and of the soundscape. Timbre is no longer at the forefront as it is with the 1.2s even as timbre remains "correct" for both. The biggest difference would be in headroom as would be obvious with the specifications albeit this is highly speaker dependent as we all know. The clear background and scalable power manifests as added jump when called for. With the VR-9s in my room the 1.2s were thus more intimate and alluring with simpler recordings but more compressed with Big Band, Opera and large scale orchestra. I've actually clipped them on Big Band but I blame Keith Johnson and RR for that LOL! Neither display the typical SS grit or overt rounding so prevalent until the early 2000s. Where the M1 shines is in its consistency as one goes from soft to loud at least until you reach the point where you might saturate your driver electromagnetics. Something you will likely not do anyway once you ease your way and find the optimal
nominal levelfor a recording and not jumping up accidentally as mentioned earlier. From the right nominal level, peaks above 100dB remain composed and not painful while delivering visceral shock. One needs to be mindful in fact because it is easy to stray into dangerous territory. The ability to control local feedback allows you to contour the punchiness of the bass but I find this more useful when in bi-amp mode as it also affects the upper registers.
All I can remember for now
I'll go over this again and add the KR VA200 in the mix as well when my Ultra 11s are home and settled