Review: Sonnet Digital Audio Morpheus DAC and Hermes Streamer

Anyone hanging around the digital water cooler for the past decade or so will know Cees Ruijtenberg from his days at the helm of Metrum Acoustics. I reviewed the Metrum Hex DAC way back in 2013, followed by reviews of the company’s Pavane and Musette DACs in 2015. Cees Ruijtenberg is also at the helm of Sonnet Digital Audio, and the Morpheus DAC can certainly be seen as a continuation of the Metrum path.

That path shares design choices that include a non-oversampling approach coupled with Cees-designed SDA-2 (Sonnet Digital Audio) R2R DAC modules. Each SDA-2 module contains an FPGA and four 16-bit resistor ladders. Hi-Res lovers fret not — the FPGA processes the incoming signal, essentially splitting 24-bit data into 12-bit streams, but everything gets put back together again before going on its way. The company claims this process keeps any switching noise, you can think of a ladder DAC as a series of switches keyed to a reference voltage, well below the music signal.