There are three digital inputs on XLR, RCA and TOSLINK (optical) connectors. In addition a computer can be connected via a Firewire interface. The accepted sampling frequencies are 44.1, 48, 88.2, 96, 176.4 and 192 kHz. AES/EBU signals in single wire or dual wire formats can be used. Digital outputs on XLR and RCA connectors are used to convert Firewire to AES/EBU and also for the insert point feature described below.
The DICE Firewire interface chip in the DAC2 uses a dual PLL scheme for clock (re-)generation. This yields a very high jitter suppression down to subsonic frequencies.
Output, level control
The DAC2 uses THAT line driver chips with low output impedance and excellent distortion figures. Separate driver chips are employed for the XLR and the RCA outputs. The output level can be set in the analog domain in four coarse steps to accommodate for the subsequent amplifier. Fine tuning of the level can be done via the digital level control which is operated via the front panel keys.
Front panel controls
The front panel shows a power key, three keys for the input selection and four LEDs for sampling frequency display. The front panel keys have several functions: The selecting of the input source, the enabling or disabling of the “insert mode”, which allows to insert a digital device in the signal chain between Firewire input and analog output and finally the setting of the output level in the digital domain with “up/down” controls.
Back panel elements
On the back panel there are three digital inputs (XLR, RCA, TOSLINK) and two Firewire sockets. Then there are two digital outputs (XLR, RCA) two pairs of analog outputs on XLR and RCA. The screwdriver operated rotary switch allows to set the analog output level in four coarse steps.
Internal jumper settings
Internal to the DAC2 there is a jumper to select the dual wire mode for 176.4 or 192 kHz signals.
Bit transparency check
The DAC2 allows to check the player software running on the computer for Bit transparency. This is done by playing a test audio file on the computer. The DAC2 then checks whether it receives the special Bit pattern from the test file. This check is running in the background of the DAC2 software, i.e. as soon as the DAC2 detects such Bit patterns it flashes three of the LEDs on the front panel.
Options for the DAC2 include an USB/DSD interface which allows to play back DSD files via the DAC2. A ST type glass fiber input is another option. For connecting the DAC2 to Thunderbolt there is a Thunderbolt to Firewire adapter available from Apple® at low cost.
The DAC2 can be used in many configurations: As a simple stand-alone AES/EBU input D/A converter, as a sound card for any Firewire or Thunderbolt equipped computer offering digital input/output and analog output facilities, as a monitoring DAC with multiple inputs including AES/EBU, S/PDIF, Firewire, Thunderbolt, USB. The DAC2 also is used in domestic setups for computer based music playback systems.