Glad to have found this thread. Lots of interesting options for power amps it seems. I just paired the SMS with the MosValve Tube Works MV-962. I found it on a local craigslist cheap. I bought because of the reputation of the Tube Works RT-921 reverb. I was not disappointed at all. My Mesa 50/50 I had planned on pairing up the SMS has been relegated to storage. I found out a couple of things about my Mesa, which is a first gen. 50/50. Apparently Mesa voiced these to pair up with, first, their studio pre and then tinkered with the voicing (their second gen. 50/50) to match it up to their newer triaxis pre.
I guess there is a mod available to help flatten out the amps response.
Here's a couple of links
http://www.seymourduncan.com/forum/show ... p?t=175529
http://grailtone.com/forum/viewtopic.ph ... 63&start=0
If I keep my Mesa it will be because this mod does what I hope it will. But as of now, I'm not even sure I want to mess around with it because I like the sound of MV-962 so much. It really works for me, for now. I haven't tried to bridge it yet though, I think I might like the headroom.
always good to read about new power amp options out there. Hope to read some more.