Costanzia,
I have not heard the Tenor OTL with Eidolons, but I would be concerned about the impedance match (not power output) for controlling the bottom end. I use an Atma-Sphere MA-2 Mk.II.3 OTL with my Eidolons (regular, not Diamond), and they are a great match together with marvelously authoritative bass, and the Atma-Sphere's have the neutrality, transparency, speed and resolution to complement the Eidolons well while nicely complementing the Eidolon's wonderful musicality and delicacy through the midrange.
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