Cambridge Audio Azur 851N

Purchased new November 2018 is a lightly-used Cambridge Audio's Flagship Azur 851N network streamer DAC digital preamplifier from a smoke and pet free home. Used only for streaming Spotify through the built-in DAC. None of the digital inputs were ever used nor was the digital preamp which can be turned off. The remote was not used either. Spotify and Tidal can be controlled buy a phone or computer and there is also a Cambridge audio app to control the unit. It features balanced and single-ended output, a 4 by 3 color TFT screen displays album art and track info, in a silver brushed aluminum case. Large torroidal power transformer. Very clear, detailed sound. Three digital filter options. Purchased with a 3 year extended warranty. Firmware updated 4/20/19

Adaptive Time Filtering upsamples everything to 24bit/384kHz hi-res quality, no matter the original source. Upsampled data passes through Twin Analog Devices DACs which are implemented in a dual differential configuration, each channel has its own DAC.
Native 24-bit/192kHz playback, USB, digital audio inputs and streaming over wi-fi including UPnP and NAS drives, Tidal, Spotify Connect, Apple AirPlay, and DSD. Over 2000 internet radio stations. Unused optional Bluetooth AptX reciever included.

Powerful digital preamp with volume output controlled by a 32bit blackfin Digital Signal processor. With preamp turned on plug directly into a power amp and use the volume dial on front or on the remote control, or turn the preamp off and plug into your preamplifier or integrated amplifier.

Inputs:
5 USB (one is on front) (one type B with ground lift switching)
2 digital optical
2 digital coax
1 AES/EBU balanced
1 control bus
Ethernet
IR

Outputs:
1 digital optical
1 digital coax
1 stereo pair RCA
1 stereo pair XLR
1 AES/EBU
1 control bus

Specs;
D/A converters
Twin Analog Devices AD1955 24-bit DACs
Digital filter
2nd Generation ATF2 up-sampling to 24-bit/384kHz. Linear Phase, Minimum phase or Steep modes.

Analogue filter
2-pole differential Bessel with DC servo (for both XLR and RCA outputs)

Digital audio inputs
1 x AES/EBU, 2 x S/PDIF coaxial and 2 x TOSLINK optical

USB Audio input
USB Type B conforms to USB Audio profile 1.0 or 2.0 (user selectable)

Analogue audio outputs
Balanced XLR and unbalanced RCA analogue audio outputs

Compatibility
UPnP: Linear PCM 16-24 bit, 11.025-192kHz Local USB media:Linear PCM 16-24 bit, 11.025-192kHz USB Audio1.0: Linear PCM 16-24 bit, 44.1-96kHz USB Audio 2.0: Linear PCM 16-24 bit, 44.1-192kHz or DSD x64 (DSD also available over UPnP streaming), TOSLINK: 16-24 bit, 32-192kHz (using high quality TOSLINK optical cable) S/PDIF: Linear PCM 16-24 bit, 32-192kHz AES3/EBU: Linear PCM 16-24 bit, 32-192kHz BT100 Bluetooth receiver: A2DP plus aptX Internet radio: 16-24 bit, 11.025-192kHz

Audio format
ALAC, WAV, FLAC, AIFF, DSD (x64), WMA, MP3, AAC, HE AAC, AAC+, OGG Vorbis

Ethernet
IEEE 802.3, 10 Base-T or 100 Base-T

Wi-Fi
IEEE 802.11 b/g or n (2.4GHz)

Reviews:
https://www.whathifi.com/us/cambridge-audio/azur-851n/review

https://www.trustedreviews.com/reviews/cambridge-audio-azur-851n