found this at bottom of a review
"Manufacturer’s Comment:
Dear Editor,
I have re-read the review about a half dozen times and think it a very thoughtful and accurate description of the tsm mme’s performance, sound and construction. That being the said, I have only a few things to mention. The tsm mme is a de-tuned version of the mxe which offers slightly wider bandwidth, is a bit more continuous sounding and resolved in character. The mme was designed around leaner sounding tubes and ss so I wanted it to be a little more forgiving yet still be a thoroughbred in what it could present in a musical manner.
Newer production offers a re-milled tweeter face plate that reduces diffraction while increasing the size of the dome’s opening to make the device sound more open and extended. The body of the tweeter is no longer a Morel mdt 30 but a hand made version made by Renaissance Audio. It is now called the Rennaissance mst 30.5.
It is my feeling that use of a copper litz speaker cable would improve the hf extension and micro definition. This is the type of cable I used in the development of the tsm.
My special thanks,
Bobby A Palkovich
President of Merlin Music Systems, Inc."
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IF 87 sensitivity is correct, I would move to more efficient speakers, and I prefer 3 way to 2 way,
I also prefer tubes (see makers SS comment), but if you keep them, then I would go for SS for enough power, say 120 wpc at 8 ohms, I never want to try for that much power from tubes, too much heat and too many tubes that start out matched, but ......