7
Technical specifications
The Ack! Industries dAck! 2.0 is a high-performance digital to analog converter. It
utilizes a transformer-coupled differential receiver compatible with AES and S/PDIF signals to
package the digital signal for data conversion. Digital to Analog conversion is provided by the
TDA1545A continuous calibration DAC chip from Philips. The DAC output is converted to
analog voltage signals using high-precision FET-input operational amplifiers from Analog
Devices biased into class-A operation for high linearity and low output impedance. Three
precision-regulated supplies power the main circuit, with bulk power provided by batteries for
perfect isolation and stable supply.
Special care has been taken to guarantee low noise and electrical isolation. The metal
chassis acts to block RFI and stray magnetic fields. The input is configured to latch very quickly
to incoming signals while isolating the downstream analog subsystem from noise and ground
loops. This also makes the dAck! an outstanding interface between hi-fi systems and PC’s,
which are notoriously noisy due to high-speed internal signals and switching power supplies.
Best performance will be obtained if a 75
Ω
cable with 75
Ω
BNC terminations is used (if
using a BNC cable, keep in mind that BNC termination alone is not an indicator of matched
impedance; many BNC terminations have a non-75
Ω
impedance spec, usually 50
Ω
).
The signal for each analog channel passes through a single ultra-precision bulk foil
resistor and a high-quality film capacitor. Ground is referenced to the preamplifer ground
through the RCA jacks.
Specifications:
Operating principle: Battery-powered digital filterless D-to-A converter utilizing active solid state
amplification (patent pending)
Input: High-bandwidth BNC input for receiving S/PDIF compliant signal
16-bit stereo only up to 96KHz
BNC male to RCA female adapter included
Outputs: Gold-plated stereo single-ended outputs with Teflon dielectric
Output
Z:
<0.05
Ω
@ 1KHz into 10K load (<30
Ω
broad band)
Downstream component should have >10Kohm input Z
2V peak-to-peak for 1KHz 0dB signal (5Vp-p: high output option)
Quiescent current:
4mA per channel (matched)
Power supply:
Ultra-low noise rechargeable battery system
Power consumption:
<0.07C
Charger supply:
300mA automatic charger
Play time per charge:
6-8 hours maximum (recommended)
Charge time: ~1hr typical after 4 hours use, <5hr from deep discharge
Battery life: 1.5-4yr depending on usage
Dimensions: 15.5cm x 19cm x 6.5cm (6.15” x 7.5” x 2.5”)
Weight: 2.25kg (5lbs)
