You should consider a used joule electra amp. I've had many and they were excellent when I had Merlins. There were never many joule amps made but they are quite special if you can find a nice used one.
Rogue Sphinx....good match with Merlin TSM?
This upgrade disease is unrelenting once it takes hold. I was first going to upgrade speakers, but after tons of comments, and some serious listening, I decided to upgrade power instead. Do you think the Rogue would be a decent improvement/upgrade from my Heaven 11 Bille amp (original version)? One thing I have to have is a remote, which the Billie does not have.