Nolitan,
I use the Amperex Pinched waist 6922 in my Lamm M2.1 monoblock amps, and my friend also uses them in his Lamm M2.2s. These are rather expensive, and tend to run between $300-500 for a pair. (I used to use Amperex 6DJ8 Orange Globes, which were almost as good, but quite a bit cheaper, @ $50-100 a pair.)
I use the Amperex Pinched waist 6922 in my Lamm M2.1 monoblock amps, and my friend also uses them in his Lamm M2.2s. These are rather expensive, and tend to run between $300-500 for a pair. (I used to use Amperex 6DJ8 Orange Globes, which were almost as good, but quite a bit cheaper, @ $50-100 a pair.)