Unison Research – Unico CDDue – Hybrid DAC w/ CD Player

With this product, Unison Research steps into digital audio.

The Unico CDDue is a high-level DAC with integrated CD reading system, it is flexible and customizable in use. CDDue combines the Unison Research sound quality and the possibilities offered by digital systems. Input from an external source or a computer allows playback of digital audio PCM and DSD in all formats and sampling rates currently available.

A look at the back of the unit demonstrates the number of inputs and outputs. Digital inputs available: USB, S/PDIF, AES/EBU, and Toslink, what you don’t see is the Bluetooth™ receiver that allows music playback from mobile devices without cables.

The output stage, as in Unison Research tradition use valves: two balanced outputs and two unbalanced. CDDue use 4 ECC83 in an innovative totem pole configuration with balanced input, this particular circuit allows high immunity to power supply noise and brings together the “triode” sound and drive capability of cathode follower.

Aesthetically it differs from past productions, CDDue has a new front also used in the Unico 150 and Unico 90: white LEDs and a white display. The new graphic display uses white OLED technology for excellent visibility in all lighting conditions and from any angle, it has a resolution of 128 x 64. The Display function allows you to turn off the display pushing a button and enjoy listening without illuminations. The display shows the most important information in large fonts, and features active in smaller fonts.

The USB input of the CDDue through latest generation D/A converter can manage signals up to 384kHz PCM and DSD up to 11,2896MHz, practically all formats and sampling rates currently available are supported.

CDDue is equipped with a Bluetooth connection that allows listening to music from any smartphone or other Bluetooth device. This connection is easy to use as the CDDue is seen from your smartphone as a headset device.

You can connect to the CDDue external digital sources (satellite receivers, digital recorders, digital mixers, etc.) There are three digital inputs on the panel. These inputs accept up to 192kHz and 24-bit (96 kHz and 24-bit the optical input). Note that the coaxial inputs accept balanced and also transfer signals encoded in DSD64 DoP.

The CD reading mechanics use an audio unit with a sleek, “slim” drawer that can only read audio CDs. The mechanism is enclosed and shielded by a thick metal cover.

The CdDue is designed to separate the digital section from the analogue one, the DAC section contains a stabilized power supply to ensure a clean and distinct power to each device on the board. The most sensitive power supplies are obtained by putting more stabilizers in cascade: the first filter and stabilizes the power supply, the second, lower voltage stabilizes and removes any residual noise. All this deployment of power is needed to put the DAC in the best working conditions and allow maximum performance of the chip.

It is possible to select from three different types of digital filter: F1 filter high slope and linear phase; F2 filter high slope and minimum phase; F3 filter low slope and linear phase. The three filters have characteristics which favor certain characteristics of the sound (temporal coherence, phase coherence, or impulse response). This allows the user to select the digital filter that best suits the installation, registration, and the listener’s tastes.

The tube stage uses two stabilizers, one for the anodic supply and one for the filaments. The path of the masses of signal and power have been designed in a particular way, and are combined in a stellar like connection in the center of the board. This point is the start of the mass connection to DAC board in order to reduce noise and disturbances.

This performance DAC has been designed with innovative circuitry, the result of extensive research and a long aging in the listening room, it presents the sonic performance of the triode with an output impedance of a cathode follower stage. The converter stage provides a balanced output with high output voltage to maintain a high signal to noise ratio and low distortion.