The Moon by Simaudio Neo 230HAD is a charmer, within its trim chassis you'll find a first class stereo preamplifier, high-resolution digital converter, and a headphone amplifier. To start my evaluations I put the 230HAD on my desktop, hooked up to my Mac mini computer and Adam Audio F5 self-powered speakers. At night for more private listening I plugged in my Sony MDR 7520 headphones. In both applications the sound was crisp and clean.
I also used the 230HAD in my main audio system, with my Bel Canto REF500S stereo power amp, and Magnepan .7 speakers. The sound was clean, clear, and beautifully balanced over the speakers. Still, it was the 230HAD's headphone amp where I dwelled the longest, swapping between Audeze LCD-2, AudioQuest NightHawk, Beyerdynamic DT 880, Grado RS-1, Oppo PM-1, and Sennheiser Momentum headphones.
To put the 230HAD's sound in perspective I compared it with the similarly sized, featured, and priced Oppo HA-1 amp. With the Audeze LCD-2 headphones the HA-1 sounded warmer and more laid-back than the 230HAD, which I felt was more see-through transparent, and presented more precisely focused stereo imaging. I'm big on clarity, so I preferred the 230HAD, but if you crave a richer tonal balance the HA-1 might be a better way to go.
The NightHawk is one of my favorite new headphones of 2015, and it sounded especially sweet when I played Jiang Ting's "Dance" CD with the 230HAD (Ting plays a pipa, which is a type of Chinese lute). The delicate sound of this instrument filling the acoustic space at Chiesa di San Colombano, a church in Lucca, Italy was simply gorgeous. I could almost reach out and touch the pipa while listening over the 230HAD, the HA-1 softened the sound just a smidge.
Listening to Amon Tobin's funky electronica album "Bricolage" with the high impedance (600 ohm) DT 880 headphones the HA-1 was thicker and weightier sounding, but the 0230HAD presented a more transparent sound that revealed greater texture and density in Tobin's music.
The 230HAD's digital connectivity runs to one optical, two coaxial, and one USB input. Digital formats include DSD64, DSD128 and DSD256, while PCM capabilities range from 44.4 kHz/16 bit to 384 kHz/32 bit. Analog connectivity includes one each stereo 3.5mm and RCA input jacks; fixed and variable output stereo RCA jacks, and a 6.3mm headphone jack. The 230HAD's all-metal chassis measures a trim 7 by 3 by 11 inches (178x76x280mm), it comes with a full function remote control.