I use the Ekstatik with a Urika 1, which unfortunately does not allow any adjustments to be made to the impedance. But I could imagine that the 75 Ohm of the Urika might be a bit too low, and that the Ekstatik could benefit from higher impedances. Linn gives a very wide range from 42 ohms to 1k...
I've been quite happy with the performance of my Audio Innovations 300, but an Audio Innovations the First power amp showed up for sale locally and I couldn't resist. This is the 4x ecc88 model, so the gain is unwieldy. I'm temporarily using it with my Chord Mojo, which is able to give a clean...