Bigtee...I'm not quite prepared to comment on the either the L2 or 21A, other than they both sound very nice and I could easily live with either of them. I just got the L2 less than a couple of weeks ago, and the 21A a week or so before that. These replaced a very highly regarded 51SE, which just did not work well in my system at all. In my system, to my ears, either of these preamps sound much better, at a quarter of the price.
In a few weeks, I should be able to formulate a meaningful comparison, as I'm going to keep only one of the preamps when all is said and done. I'm working on rolling the best tubes into these two preamps now.
The 21A, so far is just a tad noisier than the L2, but that could be tube related, thus the tube rolling.
I'll keep you posted.
I'm still trying to find out if the 21A has a standby mode, and if I'm missing a jumper.