Denon M31 (2011)

The Denon M31 is a network mini hi-fi system that Denon launched in 2011 as an entry-level "one-box" solution. It is a compact CD receiver with built-in streaming, aimed at people who wanted network audio and disc playback without a full-size component stack. It sat below the higher-end D-M39DAB in Denon's M-series lineup, and a DAB version of the same chassis (the D-M31DAB) was offered as a sibling.

The unit pairs a slot-load CD drive (handling CD, CD-R, and CD-RW) with a 24-bit/192kHz DAC for both disc and network playback. A Class D amplifier drives 6-16Ω speakers. The front panel is aluminum, with a small three-line monochrome FL display. Owners found it hard to read in dim rooms, since it isn't backlit. Connectivity is the M31's strong suit for its class: built-in Wi-Fi (802.11 b/g) plus Ethernet, AirPlay, DLNA 1.5, and Spotify Connect. There is one optical and one coaxial digital input, a single AUX analog input, a headphone jack, and two USB-A ports (front and rear) for MP3, WMA, AAC, FLAC, and WAV playback. An FM/AM tuner is also built in. The remote is the RC-1188.

The spec sheet has a discrepancy in rated power. AVI Japan lists 39W × 2, while Denon UK states 65W. It is likely a difference in measurement standard or interpretation, and the two sources agree on most other figures. Frequency response for CD input is 20Hz-20kHz (±0.5dB) with 105dB S/N, 0.05% THD, and 100dB dynamic range. AUX input loosens to ±1.0dB, 100dB S/N, and 0.04% THD. Dimensions are 280 × 80 × 306 mm (W×H×D) and weight is 4.0 kg. The M31's launch year of 2011 places it well after the period covered by most archive materials, and no dedicated review has surfaced in the archive's holdings. Contemporary publications focused on equipment sales rather than product reviews during that era (HiFI-Stereo, August 1995, p.88), and the period press mainly listed authorized dealers and sales offers for existing brands rather than covering this model.