To which lamm 2.1 amplifiers are you referring to?
The M2.1, which is the 200 wpc, hybrid monoblock amplifier? (FYI, which has been superceded by the M2.2)
Or,
The ML2.1, which is the 18 wpc SET tube monoblock amplifier?
It appears that you are referring to the M2.1 amplifiers, correct? If so, I have just gotten a pair, used, and they are terrific, IMHO. (After hearing them in two of my friends' systems, I was so impressed that I bought a pair myself. Lucky for me, a local seller sold them to me for $7K.)
Strengths: Very musical; Very powerful; Imaging is spot-on, as is the soundstaging. The treble is very, very good and the bass is outstanding. The mid-range has just a touch of that tube lushness, that make vocals a real treat to listen too. (As it has only one tube per amp, you can not only tweak the sound, to an limited extent, and since it only has two tubes, it is (relatively) cheap to tube roll. I have not done this yet, but my friend, (who has the M2.1s too), has and says the sound can be brought to even higher heights by using NOS tubes.)
Weaknesses: Very Expensive, even used; As it operates in Class A up to 36 wpc, it uses a fair amount of power, and thus your electric bill will be a bit higher; Again, as it operates in Class A for a significant amount, it runs a bit hot.
(When I say a bit hot, I do mean "only" a bit, but more than just warm. It will heat up the room, but not like the big tube amps, (i.e. the VTL 450s or 750s) or even the big pure Class A amps (i.e. Pass Aleph or XA series.) You can put your had on the top of the amp, and keep it there without fear of burning yourself.
One other point which I will make is that the power does not double as you halve the impedance. (However, I have a Mark Levinson No. 23 (A SS stereo 200 wpc amp, which does double in power as the impedance is halved), and it turns out that it is not quite as powerful as my M2.1s monoblocks, when they drive my Revel Studios (which have an impedance of 4 ohms). I think the separate power supplies really do supply much more power than I was ever led to believe.
Another friend of mine has the newer M2.2s and while I have only heard them in his system, the differences are very subtle from the M2.1s. (i.e. slightly more powerful (220 wpc) and maybe just a touch more treble, maybe.) BTW, I am not sure which Rowlands you have, but this same friend used to have the Rowland 501s and while he said that they were good, he said that his Classe CA-401 was better, (as were his VTL MB-450s), and that his Lamms are the best of the bunch. He used to use the Rowlands during the summer months (as they ran cool), and the VTLs in the winter months (as they ran really hot). He has now sold both, and only uses the Lamm M2.2s. He uses the Avalon Eidolons, which really demand a lot of power to make the amps come to life, and even though technically the Lamms are 1/4 to ½ as powerful as the other amps, they actually sound better and even the bass is better. I can not imagine the speaker that this amp could not drive. (I know that I could have settled for the M1.1, which only has 100 wpc, as I only turn my preamp up to about the 10:00 o'clock position.)
Well, hope this helps!
Good Luck in your search!
PS I have found the last pair of amplifiers I ever plan on buying in my lifetime.
The M2.1, which is the 200 wpc, hybrid monoblock amplifier? (FYI, which has been superceded by the M2.2)
Or,
The ML2.1, which is the 18 wpc SET tube monoblock amplifier?
It appears that you are referring to the M2.1 amplifiers, correct? If so, I have just gotten a pair, used, and they are terrific, IMHO. (After hearing them in two of my friends' systems, I was so impressed that I bought a pair myself. Lucky for me, a local seller sold them to me for $7K.)
Strengths: Very musical; Very powerful; Imaging is spot-on, as is the soundstaging. The treble is very, very good and the bass is outstanding. The mid-range has just a touch of that tube lushness, that make vocals a real treat to listen too. (As it has only one tube per amp, you can not only tweak the sound, to an limited extent, and since it only has two tubes, it is (relatively) cheap to tube roll. I have not done this yet, but my friend, (who has the M2.1s too), has and says the sound can be brought to even higher heights by using NOS tubes.)
Weaknesses: Very Expensive, even used; As it operates in Class A up to 36 wpc, it uses a fair amount of power, and thus your electric bill will be a bit higher; Again, as it operates in Class A for a significant amount, it runs a bit hot.
(When I say a bit hot, I do mean "only" a bit, but more than just warm. It will heat up the room, but not like the big tube amps, (i.e. the VTL 450s or 750s) or even the big pure Class A amps (i.e. Pass Aleph or XA series.) You can put your had on the top of the amp, and keep it there without fear of burning yourself.
One other point which I will make is that the power does not double as you halve the impedance. (However, I have a Mark Levinson No. 23 (A SS stereo 200 wpc amp, which does double in power as the impedance is halved), and it turns out that it is not quite as powerful as my M2.1s monoblocks, when they drive my Revel Studios (which have an impedance of 4 ohms). I think the separate power supplies really do supply much more power than I was ever led to believe.
Another friend of mine has the newer M2.2s and while I have only heard them in his system, the differences are very subtle from the M2.1s. (i.e. slightly more powerful (220 wpc) and maybe just a touch more treble, maybe.) BTW, I am not sure which Rowlands you have, but this same friend used to have the Rowland 501s and while he said that they were good, he said that his Classe CA-401 was better, (as were his VTL MB-450s), and that his Lamms are the best of the bunch. He used to use the Rowlands during the summer months (as they ran cool), and the VTLs in the winter months (as they ran really hot). He has now sold both, and only uses the Lamm M2.2s. He uses the Avalon Eidolons, which really demand a lot of power to make the amps come to life, and even though technically the Lamms are 1/4 to ½ as powerful as the other amps, they actually sound better and even the bass is better. I can not imagine the speaker that this amp could not drive. (I know that I could have settled for the M1.1, which only has 100 wpc, as I only turn my preamp up to about the 10:00 o'clock position.)
Well, hope this helps!
Good Luck in your search!
PS I have found the last pair of amplifiers I ever plan on buying in my lifetime.