Absence of digital filter yields accurate impulse response.

Absence of brickwall filter yields phase accuracy across the band.

Absence of extraneous components yields purity of signal.

Absence of complexity yields purity of tone.


Well spoken.

Conceptualized by Ryohei Kusunoki and made popular by Audio Note and Sakura Systems, the original dAck! idea was brought about on the Gainclone discussion boards. We were not happy with the conventional CS8412->TDA1543 DAC design at many levels. The passive I/V conversion used in that design had three major faults – the output impedance was too high, the signal was degraded while passing through low-quality electrolytic capacitors, and the output utterly anemic. Sonically, we felt the resulting sound was unfocused, grainy, and undynamic. Furthermore, the character of the conventional Kusunoki design is completely unpredictable from system to system.

The battery-based power supply provides the foundation for dAck!'s unique sound. The transformer, rectifier, and filtering circuits present in most digital to analog converters contribute to a gritty, shrill, and unrestrained sound – something digital sources cannot afford if the end goal is to convey music. Three Linear Technologies precision regulators are used to further eradicate noise in already ultra-quiet battery supplies. Oversized supply capacitors are highly regarded Panasonic FC series incorporating ample bypassing by high quality film parts. Proper grounding – extremely important for any digital system – is accomplished on the high quality PCB with oversized traces routed for noise prevention and isolation from stray currents.

The dAck! is designed to provide tonal purity, extraordinary soundstage coherence, and timbral accuracy, but not at the expense of dynamics. Its sound is never fatiguing. A Philips TDA1545A multi-bit chip – the simplest of converters – is the heart of the conversion system. It accepts signals provided by the Cirrus Logic digital receiver, which decodes 16-bit stereo datastreams up to 96KHz provided through a high-bandwidth 75Ω BNC digital input. The D-to-A chip's output is converted into voltage waveforms using high input-impedance FET-input amplifiers from Analog Devices that are biased into high class A using cascode FET current sources. The analog signal travels through only one ultra-precision resistor and one reference-grade film capacitor before reaching the preamplifier. The resulting sound can only be characterized as clear and coherent throughout the midband with delicate upper mids and highs.

Its small size makes it easy to fit into any installation. Faceplates are carefully machined from 1/4" aluminum plate, and fitted onto a distinctive steel enclosure. Each unit is meticulously hand-built, and tested in a real system for several hours before deployment. By selling factory direct, the dAck! provides the same caliber of performance as vastly expensive converters costing thousands of dollars at a small fraction of the cost.



Copyright and Trademark Notices Copyright (c) Ack! Industries and/or its licensors, 2005, all rights reserved. The Ack! logo is a registered trademark of Ack! Industries.