The DAC1 is a stereo 24 bit / 96khz D/A converter designed with the aim of keeping an absolutely uncompromised audio signal path. Much detail and thought was spent on the digital input as well as the analogue output stage. Both have in common the purest possible approach in audio design, aspiring for nothing less than excellence. This is coupled with an ergonomic design that gives the user immediate access to all necessary functions, while keeping an uncluttered and thus easy-to-use front panel. This combination makes a truly professional D/A converter catering for the highest expectations.

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 and 96kHz. AES/EBU signals on a single connector are used. Each XLR input is actively routed to a corresponding XLR digital output, allowing monitoring at multiple stages in a digital studio setup.

Synchronization:
Several signal reclocking schemes are combined for extremely high jitter attenuation, making the DAC1 virtually immune to jitter over a very wide bandwidth.

Converters:
The correlation technique (using two converters per channel) which was already successfully employed in the ADC1 gives the DAC1 an edge over other D/A converters with equal wordlength and sampling rate specifications, resulting in improved SNR and THD.
Outputs:

The discrete Class A outputs have a virtually zero Ohm output impedance, but still can drive large loads without stability problems. Output levels can be set between -infinity and +27dBu. 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:
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.

Frontpanel Elements:
Four switches for input selection
Four LEDs for sampling frequency display (44.1 / 48 / 88.2 / 96)
Three LEDs for input wordlength display (1..16, 17..20, 21..24 bits)
One Emphasis LED
Two 25 turn trim potentiometers for fine trimming the output level

Backpanel Elements:
Three digital inputs on XLR
One digital input on Toslink
Three digital outputs on XLR, buffered from XLR inputs
Two analog outputs (channel 1,2) on XLR
Output level range switch (high / low) Remote connector with the following signals:
Power supply to external faders
Tapers from two external faders
four input selection switches
four LEDs for input selection switches

DAC1 technical data:
Digital Inputs:
(3) XLR connectors, female, AES/EBU standard, accept professional or consumer format
(1) Toslink connector (optical), accepts professional or consumer format
Sampling Frequencies: 44.1 kHz, 48.0 kHz, 88.2kHz or 96.0kHz
Maximum Input Wordlength: 24 Bits

Analog Output:
Two XLR Connectors, maleSymmetrical outputs, no servo, DC coupled, short circuit proof

Asymmetrical operation:
connect pin 1 (ground) and pin 2 (hot). Leave the unused pin unconnected!

Output impedance: virtually 0 Ohm
Output level "low" mode: variable from -infinity to +15dBu
Output level "high" mode: variable from -infinity to +27dBu
Output level variable with two 25 turn trim potentiometers
Output stage: Discrete Class A

Converters:
Correlation technique using two converters per channel
Synchronization:
Synchronized via input signalSampling Frequencies: 44.1, 48.0, 88.2, 96.0 kHz, tolerance +- 80ppm

Remote Connector:
15 pin DSUB connector pinout:
1 ground
2 ground
3 key # 2 (switch to ground, selects input # 2)
4 key # 4 (switch to ground, selects input # 4)
5 LED # 1 (anode of LED for key # 1, cathode at ground)
6 LED # 3 (anode of LED for key # 3, cathode at ground)
7 ground
8 +5V supply for external fader (connect fader between +5V and ground)
9 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

Frontpanel elements:
- Four switches for input selection
- Four LEDs for sampling frequency display (44.1 / 48 / 88.2 / 96)
- Three LEDs for input wordlength display (1..16, 17..20, 21..24 bits)
- One Emphasis LED
- Two 18 turn trim potentiometers for fine trimming the output level

Backpanel Elements:
- Three digital inputs on XLR
- One digital input on Toslink
- Three digital outputs on XLR, buffered from XLR inputs
- Two analog outputs (channel 1,2) on XLR
- Output level range switch (high / low)
- Remote connector with the following signals:
Power supply to external faders
Tapers from two external faders
four input selection switches
four LEDs for input selection switches

Power:
Mains Voltage: 110 / 220 Volts with voltage selector
Fuse rating: 500 mA slow blow
Power Consumption: 80VA max.

Measurements:
Measurements taken at the following conditions (unless otherwise noticed): +27dBu output level, 44.1kHz sampling frequency (fs), 22kHz measurement bandwidth

Frequency Response:
@ fs = 44.1kHz: DC ... > 20kHz +- 0.05dB
@ fs = 48.0kHz: DC ... > 20kHz +- 0.05dB
@ fs = 88.2kHz: DC ... > 40kHz +- 0.5dB
@ fs = 96.0kHz: DC ... > 40kHz +- 0.5dB

Dynamic Range:
115dB unweighted, 118dB A-weighted

THD+N @ 1kHz:
-107 dBr @ -3 dBFs input (0dBr = +27dBu)
-105 dBr @ 0 dBFs input (0dBr = +27dBu)

SNR @ -40dBFS input:
114dBr unweighted (0dBr = +27dBu)
117dBr A - weighted (0dBr = +27dBu)

Linearity:
from 0 to -100dBFs input level: < +-1dB deviation
from ideal from -100 to -130dBFs input level: < +-1.5dB deviation from ideal

Crosstalk:
< -130dB, 0..20kHz

Output Level Range:
range switch "high", balanced: +27dBu ...-infinity dB
range switch "low", balanced: +15dBu ... -infinity dB
range switch "high", unbalanced: +21dBu ...-infinity dB
range switch "low", unbalanced: +9dBu ... -infinity dB

Output impedance:
0.2 Ohm, outputs are short circuit proof