I do not have the WEE but have tried my esc1001, SRD7SB and SRD7mk2 with various amps including a fully balanced B22 via the speaker out and other tube amps, used for driving normal home speakers, to drive my O2mk1. I have found that the result is much dependant on what is feeding it. I believe that the WEE ought to be the same as well.
The tube amps include the audio note kassai, neiro, border patrol, almaro and so on. I own some of them or either had them in my house on extended trial periods (more than 1 month). I have found that the ones with massive power supplies injected the O2mk1 with plenty of life. An added active matched preamp did a lot as well.
For whatever the reson, I preferred the results from tube amps to the transistor amps.
As the WEE operates in a similar way to the other energizers, I believe that a "high power" front end should make a big difference to the sound presented.
Edited by Victor Chew - 11/16/10 at 5:25pm