Description
MAIN FEATURES
Inputs
There are three digital inputs on XLR connectors, and one on TOSLINK (optical). 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. Each XLR input is actively routed to a corresponding XLR digital output, allowing for monitoring at multiple stages in a digital studio setup.
De-jittering
Several signal re-clocking schemes are combined for extremely high jitter attenuation, making the DAC1 virtually immune to jitter over a very wide bandwidth, down to subsonic frequencies.
Converter
The correlation technique (using two converters per channel) which was already successfully employed in the ADC1, results in improved SNR and THD figures.
Outputs
In the DAC1-MK2 the discrete Class A outputs have a virtually zero Ω output impedance, but still can drive large loads without stability problems. The DAC1-MK3 uses discrete operational amplifiers of our own design. Called OP1-BP, this operational amplifier probably is the best audio op-amp currently available. Output levels can be set between −infinity and +27 dBu. The outputs are symmetrical, but do not have any sound degrading servo mechanisms built in. For asymmetrical operation only one leg of the XLR connector (plus ground) is used.
Remote control
By hooking up an analog potentiometer or fader to the remote connector, the output level can be remote controlled. This level control happens in the digital domain. The input source selection can also be remote controlled. For the DAC1-MK3 there is a IR remote control option for the output level available.
Front panel controls
The front panel shows four switches for the input selection and various LEDs for sampling frequency, input word-length and signal presence display. The DAC1-MK2 in addition has two 25 turn trim potentiometers for fine trimming the output level.
Back panel elements
On the back panel there are three digital inputs on XLR and one optical digital input on TOSLINK. Then there are three digital outputs on XLR, buffered from XLR inputs and two analog outputs on XLR. One of the digital XLR outputs can be switched to output the currently selected input.
The DAC1-MK2 in addition has a output level range switch (high/low) while the DAC1-MK3 uses a rotary encoder instead, which allows to set the output level of both outputs simultaneously in a range of 32 dB with a resolution of 1 dB. The 25 pin DSUB remote connector allows to connect a wired remote control unit for level control and input source selection.
Optional interfaces
Options for both the DAC1-MK2 and the DAC1-MK3 include a Firewire (Thunderbolt) interface and a USB interface. The latter is also capable to convert DSD to PCM signals which allows to use the DAC1 for playback of DSD signals from a computer. Other options are an ST type glass fiber input and an infrared remote control for the control of the audio volume (DAC1-MK3 only). The DAC1/DAC1-MK2 can be upgraded to a DAC1-MK3 by replacing the analog section.
Applications
The DAC1 finds its place in mastering studios for monitoring as well as for integrating an analog chain in a digital environment. With the plethora interfacing options (AES/EBU on XLR, TOSLINK and ST type glass fiber, USB, Firewire, Thunderbolt) the DAC1 is ready for all kinds of setups, even for use in a domestic environment. The output level can be set in a wide range, accommodating for all kinds of subsequent amplifiers. With the wired remote control the DAC1 can be easily controlled and monitored via a handy little box.
Technical specifications
TECHNICAL DATA
Power
– Mains voltage: 115 V or 230 V with voltage selector
– Fuse rating: 500 mA slow blow
– Power consumption: 80 VA max.
Size
– Depth: 30 cm
– Width: 43,3 cm (19″)
– Height: 4,4 cm (1HU)
AES/EBU Input
– Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz
– Maximum sampling frequency deviation: ±80 ppm
– Maximum input word-length: 24 Bits
– Channel Status Data: Input accepts professional or consumer format
– Connector: Three XLR female (110 Ω), one TOSLINK (optical)
AES/EBU Output
Three XLR male connectors with buffered versions of the corresponding XLR input. One of the outputs can be switched such that it reflects the currently selected input to the DAC.
Analog Output DAC1-MK2
– Two XLR male connectors, pin 1 ground, pin 2 hot, pin 3 cold
– Symmetrical
– No servo circuit
– Not earth free
– Short circuit proof
– DC coupled
– Class A
– Output impedance: 0.2 Ω
– Output level: continuously variable between −∞ dBu and +27 dBu including a 12 dB high/low switch
Analog Output DAC1-MK3
– Two XLR male connectors, pin 1 ground, pin 2 hot, pin 3 cold
– Symmetrical
– No servo circuit
– Not earth free
– Short circuit proof
– DC coupled
– Class A
– Output impedance: less than 100 Ω
– Output level: variable between −4 dBu and +27 dBu in 1 dB steps
Wired Remote Control Connector
15 pin DSUB connector pinout:
– 01 Ground
– 02 Ground
– 03 Key #2 (switch to ground, selects input #2)
– 04 Key #4 (switch to ground, selects input #4)
– 05 LED #1 (anode of LED for key #1, cathode at ground)
– 06 LED #3 (anode of LED for key #3, cathode at ground)
– 07 Ground
– 08 +5 V supply for external fader (connect fader between +5 V and ground)
– 09 Not connected
– 10 Key #1 (switch to ground, selects input #1)
– 11 Key #3 (switch to ground, selects input #3)
– 12 LED #2 (anode of LED for key #2, cathode at ground)
– 13 LED #4 (anode of LED for key #4, cathode at ground)
– 14 Fader channel 1 taper
– 15 Fader channel 2 taper
Options
– Firewire/Thunderbolt interface
– USB interface with DSD to PCM conversion capability
– ST glass fiber input
– IR remote control for volume control (DAC1-MK3 only)
– Wired remote control for volume control and inout source selection
Measurements DAC1-MK2
Measurements taken at the following conditions (unless otherwise noticed): +27 dBu output level, 0 dBFS input level, 44.1 kHz sampling frequency (fs), 22 kHz measurement bandwidth.
Frequency Response:
– Fs = 44.1 kHz, DC…20 kHz: ±0.05 dB
– Fs = 48 kHz, DC…20 kHz: ±0.05 dB
– Fs = 88.2 kHz, DC…40 kHz: ±0.5 dB
– Fs = 96 kHz, DC…40 kHz: ±0.5 dB
Dynamic Range:
– 115 dB unweighted
– 118 dB A-weighted
THD+N at 1kHz:
– At −3 dBFS input: −104 dB
– At 0 dBFS input: −105 dB
SNR at −40 dBFS input:
– 114 dB unweighted, relative to full scale output
– 117 dB A-weighted, relative to full scale output
Linearity:
– From 0 dBFS to −100 dBFS input level: less than ±1 dB deviation from ideal
– From −100 dBFS to −130 dBFS input level: less than ±1.5 dB deviation from ideal
Crosstalk:
Less than −130 dB, DC…20 kHz
Measurements DAC1-MK3
Measurements taken at the following conditions (unless otherwise noticed): +27 dBu output level, 0 dBFS input level, 44.1 kHz sampling frequency (fs), 22 kHz measurement bandwidth.
Frequency Response:
– Fs = 44.1 kHz, DC…20 kHz: ±0.25 dB
– Fs = 48 kHz, DC…20 kHz: ±0.25 dB
– Fs = 88.2 kHz, DC…30 kHz: ±0.75 dB
– Fs = 96 kHz, DC…30 kHz: ±0.75 dB
– Fs = 176.4 kHz, DC…40 kHz: ±0.75 dB
– Fs = 192 kHz, DC…40 kHz: ±0.75 dB
THD+N at 1kHz:
– At −3 dBFS input: −112 dB
– At 0 dBFS input: −115 dB
SNR at −40 dBFS input:
– 129 dB unweighted, relative to full scale output
– 132 dB A-weighted, relative to full scale output
Linearity:
– From 0 dBFS to −100 dBFS input level: less than ±0.05 dB deviation from ideal
– From −100 dBFS to −120 dBFS input level: less than ±0.2 dB deviation from ideal
Crosstalk:
Less than −110 dB, DC…20 kHz
