The Grace Design m900 is a portable, desktop friendly headphone amplifier/DAC/preamp in one, designed to deliver musical and transparent audio playback from USB, S/PDIF or TOSLINK sources for professionals and enthusiasts. The m900 provides analogue and DAC quality in a rugged, portable and affordable unit.

Equipped with the latest generation AKM 4490 chip, the m900 offers 32-bit processing and supports sample rates up to 384kHz PC or 256x DSD. The USB interface operates in asynchronous mode allowing the m900 to be the clock master that makes the system immune to USB bus jitter. S/PDIF and Toslink inputs allow this unit to enhance to any DAW interface with true reference quality D/A conversion, headphone monitoring and stereo speaker control.

Transimpedance amplifier topology coupled to a zero ohm output impedance driver provides spacious and transparent headphone performance with a tight, enveloping low end. The latest generation crossfeed circuit rounds out the design by simulating an acoustic listening environment in the headphones.