I believed you must have tried the two impedance settings in the back of the Lamm M1.1. 1-6 and 8-16 impedance settings.
I have a Revel Salon 2 and tried it with the LP 140 and it didn't work quite well. Now I have the Lamm M2.2 that works great with the Salon 2. I know that the Confidence is a bit more efficient than the Salon 2, but it still dives deep to around 3 ohm. I doubt you would gain a lot with the LP 140 with the Confidence.
Perhaps the LP275 monos work better with the Confidence.
I have a Revel Salon 2 and tried it with the LP 140 and it didn't work quite well. Now I have the Lamm M2.2 that works great with the Salon 2. I know that the Confidence is a bit more efficient than the Salon 2, but it still dives deep to around 3 ohm. I doubt you would gain a lot with the LP 140 with the Confidence.
Perhaps the LP275 monos work better with the Confidence.