DAC1-MK3

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 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.

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 ), 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
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
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