The Reference DSD1.1 is a high performance D/A convertor utilising  the advanced X-MOS module to support DSD playback up to DSD256.

Equipped with a Hi-Speed Audio USB2.0 interface for the digital input from computer.

Supporting Native DSD streams mode, pure original DSD signal .

It also uses the special USB GND isolation design, which keeps the noise away from the computer's USB.  Driver for Apple device (MAC/ phone/ pad) also for  Andriod devices.

  A choice of APPs for DSD and PCM files Apple/Andriod .

  Special tube buffer design before the RCA output for increased fidelity.
  Also equipped with a headphone output for impedance ranging from 10 to 600 ohm.
  Multipile PCM digital filter option
  PCM digital filter mode:
1. Short delay Sharp
2. Short delay Slow
3. Sharp Roll-off
4. Slow roll-off
5. Super Slow roll-off
The user selectable digital filter chooses various modes. for smooth, sharp, fast, slow, etc 

Review from Hi-Fi+ magazine

D-Linear7
High Definition digital music interface
Key Functions:
1. Digital stream master network audio interface (24Bit/192KHz)
2. Digital stream Hard Disk recorder (24Bit/96KHz)
3. WI-FI/LAN Internet radio
4. Upgrade operating system from USB

The Linear 7 High Definition digital music interface contains audio coding and decoding software that can process 24Bit/192KHz high bit rate digital master tape audio streams at very high speeds and supports the decoding output of all types of digital audio formats, such as (WAV//WMA/ APE/FLAC/ALAC/ACC ). In the future, through firmware upgrading, the device will support even more audio formats.
It can also be used as a network music server center. It can support any network hard disc NAS and can share network resources through WI-FI/LAN. It can also be used as an Internet radio. With a built-in channel list, it can receive over ten thousand digital Internet radio stations from all over the world.
The linear 7 adopts the specialized 32-bit high-performance embedded multi-media processor CPU, multimedia DSP chip solution and the reference clock system of the industrial-class digital phase-locked loop (DPLL) system, effectively reducing clock jitter in transmission of digital audio signals so as to achieve an ultra-low jitter index.
The Linear 7 has an LCD display with a touch screen allowing the user simple operation. The screen can display the artist's name/internet radio station information and the sampling rate. It also includes an easy to use high qualityfully functioning remote control. The D-linear7 support control by computer and Google Android smartphone or pad etc.
Specifications: Digital output signal level 0.5Vpp (RCA), 3Vpp (AES) Digital output impedance 75ohm
(RCA ) , 110ohm (AES), Analogue output RCA.
Dimensions / Weight 100mm x 225mm x 188mm (HxWxD) / 1.5 kg (net)

Link to review

https://www.enjoythemusic.com/magazine/equipment/0311/opera_audio_d_linear7_d_linear8.htmhttps://www.enjoythemusic.com/magazine/equipment/0311/opera_audio_d_linear7_d_linear8

Link to review [Serbian mag'] https://www.opera-consonance.com/review%20pic/D-linear7_8/D-Linear7-8_2012.1.pdf

D-Linear 8
24bit/192khz Decoder Key Functions:
1. USB wireless DAC digital receiver
2. Universal DAC for CD transports, The Consonance HD interface, DVD players, Blu-ray players, cable TV decoders and satellite receivers
3. High-end Headphone amp
4. RCA and Balanced analogue outputs.

The newly designed Consonance Linear 8 Decoder is more than simply a new product, it is also a new concept in audio enjoyment. The heart of the linear 8 is the PCM1792 24-Bit chip running at a 192kHz sampling rate. Our decoder uses the Transceiver has a low jitter analog PLL, and a PLL lock range from 32khz to 192khz .

There are 4 selectable digital inputs on the rear panel consisting of a coaxial RCA, AES, Toslink and an antenna for digital USB computer input. The basic signals are displayed through the front panel meter. This meter will also indicate when the signal is locked in.

The Linear 8 has a wireless USB 2.4G ISM license free band, adaptive frequency hopping random ID pairing and non-compressed 48k/16bit sampling. This wireless system is like a secondary music system that will compliment your existing main setup. It can be operated at a considerable distance (up to 25m) from your primary system, there are no bothersome cables. Your computer can be used as a main source of your music playback allowing you more freedom and worry free operation in your musical enjoyment.

The Linear 8 includes a hi-end headphone amplifier, 32ohm to 600ohm.
Its size is unobtrusive so it can be positioned anywhere, and it has a very user friendly interface.
Specifications: Signal output 2.5V RMS (RCA, XLR) Digital inputs 1 Coaxial, 1 Optical, 1 AES and wireless USB digital inputs Analog outputs Gold plated RCA / phono unbalanced and gold plated XLR balanced, Gold plated 6.5mm headphone jack Frequency response 0 Hz-50 kHz Signal-to-noise ratio More than 118dB (RCA, XLR) Distortion Less than 0.001% ( RCA,XLR) Dimensions / Weight 100mm x 225mm x 320cm (HxWxD) / 3.5 kg (net)