I am considering two amps to drive the HE-560 phones. I chose them because they are powerful and well recommended.

1. Schiit Mjolnir

8 watts/ch. into 32 ohms

5 watts/ch. into 50 ohms

2, Emotiva Mini-X a100 (a speaker amp)

50 watts/ch. into 8 ohms

Two questions:

1. Does anyone know how to predict the power of the Emotiva into 32 ohms?

2, I've seen many strong recommendations of speaker amps for inefficient phones such as the HE-500. (The HE-560 is 1 dB more efficient than the HE-500 but that difference is negligible.) Are the recommendations for speaker amps simply based on their greater power or is there something else at work?