S. Andrea Sundaram has posted a review of the Simaudio Moon Neo 230HAD headphone amplifier-DAC ($1500) at SoundStage! Xperience. His conclusions:
“While any competently designed solid-state headphone amp should produce a sound that’s close to neutral, audiophiles base their buying decisions on the subtler ways in which amplifiers differ. The 230HAD has prominent but controlled bass, relaxed and refined treble, and a full-bodied midrange that provides a coherent transition between the two — a sonic profile I found worked well with all types of music and a variety of headphones.”
You can read the full review here.