How does the sound of the Ack!
Industries dAck! compare to "X" manufacturer's DAC? (What is the
level of performance of this DAC? / Will the dAck! work well in
Why is my dAck! quieter than
“X” manufacturer’s DAC? / How do I properly A/B my dAck! against
What do I do about turn-on/turn-off
Does the dAck! require break-in
/ what is the run-in time?
What about jitter? Does it matter
for the dAck!?
Will you offer a Toslink or glass input option?
How long can I expect my batteries to last?
Where do I get replacement batteries
/ Can I buy replacement batteries off the shelf?
How does the sound of the Ack! Industries dAck! compare to "X" manufacturer's DAC? (What is the level of performance of this DAC? / Will the dAck! work well in my system?)
We obviously cannot answer this question for every converter
on the market or for every system the dAck! might be used in. The Ack!
Industries dAck! will likely behave more similarly to other non-oversampling
DACs than to oversampling DACs, but it has a unique character that is unlike
anything on the market. It is designed to be competitive with DACs in the
$1500+ range. Please inquire for specifics.
Why is my dAck! quieter than “X” manufacturer’s DAC? / How do I properly A/B my dAck! against other converters?
While many CD players have monstrous output
drives of about 2VRMS, we have chosen to use a smaller output level
of 1V (0.7VRMS, or 2V peak-to-peak) for a number of reasons. Firstly,
the dAck! was initially designed to complement analog systems. Typical
phonostages amplify moving coil signals to roughly this level. Thus,
when switching from analog to digital in your system, you will conveniently
stay in a similar regime of operation. Additionally, most volume
potentiometers tend to operate best at high settings because they
are less noisy and the channel matching is better in the higher
regime. In most digital systems, a 9:00 setting is already very
loud; with the dAck! it will be at 12:00-1:00. For customers using
digital-only sources, or those with low gain in their systems (e.g.,
passive preamps or low-power amplifiers), we offer a high output
version that outputs a 2VRMS.
It is well known that in A/B tests, the louder
device almost always wins so for an objective comparison it is important
to match output levels. To appropriately match levels, put in a test
tone CD (broadband noise is preferred but a 1KHz tone is OK). Using the
louder source first, measure the output amplitude across the speaker terminals
with a voltmeter in AC mode or with an oscilloscope while playing the tone
at the desired audition level. Next, install the second source (the dAck!)
and adjust volume control to achieve the same measurement. When you are
switching between sources, alternating between these two volume settings
will give you consistent output levels between the pieces under comparison.
What do I do about turn-on/turn-off thump?
When the dAck! is first turned on, the output capacitors
will charge up momentarily as they start to block the DC from the conversion
circuit. Because of the speed of the dAck! 2.0 output stage, this thump is
more prominent than in the original dAck!. The magnitude of this thump is
about 1.5V which is a slight bit louder than the loudest transient that comes
out of the dAck! during music playback (less if you are using the high output
version). This thump is a low rate signal and will not damage your loudspeakers
or electronics because it is about the same as a big orchestral transient during
playback. If it bothers you, turn down your volume control slightly before
turning your dAck! on or off.
Does the dAck! require break-in / what is the run-in time?
Since the dAck! is battery powered, owners do not have
the luxury of leaving it on all the time for rapid run-in. On a new dAck!,
the capacitors need to form the dielectric and there is some diffusion that
occurs in the semiconductors. A new unit should stabilize within about 2
weeks (~2-4hr play time per day) to a warm welcoming tone, and any initial
harshness should disappear. Customers have reported a second break-in transition
at about 100-125 hours during which the sound opens up tremendously to its
final performance level
What about jitter? Does it matter for the dAck!?
Jitter is clock timing error that occurs during the
transmission of the digital signal from the digital source to the
DAC. While its existence has been known for years, its effects in
audio are not well understood. What is known is that the frequency
signature of jitter can dramatically affect the soundstage coherency
and complex transient performance of a D-to-A converter. The dAck!
has built-in defenses against jitter, but no device can completely
remove it; jitter can only be attenuated, not removed. The dAck!’s
performance scales directly with quality of the datastream it is
fed, so it is worthwhile to get the best quality transport one can
Robert Harley has published several excellent articles
on the subject. These articles are available for free download on Stereophile’s
Transport of Delight: CD Transport Jitter”
Will you offer a Toslink or glass input option?
No. For consumer audio we believe that optical
interconnection has more drawbacks than advantages. Its major advantage
is noise isolation and low attenuation over long distances. The
coaxial input is more robust and less sensitive to vibration. It
does not age like optical since it is not sensitive to dust, and
does not require messy optical coupling fluids for best performance.
Additionally, coax is more amenable to the way audio connoisseurs
tend to use equipment; switching cabling is more reliable and the
signal paths are short enough that the length advantage of Toslink
is moot. The dAck! is galvanically isolated from the source so there
is no possibility of ground loops or hum.
For those with Toslink-only sources we can recommend
the use of the Monarchy DIP classic or a simple Toslink-to-RCA converter.
There are several on the market, please inquire for suggested products.
can I expect my batteries to last?
This is difficult to answer specifically. With the recommended
usage cycle of up to 8 hours of listening before every recharge,
get between 750 and 1000 charge/discharge cycles from your cells
before they suffer diminished performance (this may or may not
be noticeable). What this translates into in terms of years depends
on your usage habits. If you use your dAck! 3-6 hours a day (one
to two charge cycles), you can expect to replace the cells after
about 1.5 to 2 years.
While the cells can readily be used in 6 to
8-hour cycles, we recommend usage in 4 hour increments for two
reasons. First, 4 hours is a very shallow discharge cycle, which
results in greatest battery longevity. Secondly (and perhaps more
importantly), a 4-hour cycle encourages more consistent charge habits.
This prevents the worst case scenario of leaving your dAck! on
overnight one too many times, destroying the batteries.
You can tell if the battery should be replaced when
you notice the sound gets much less sweet after a few hours of playback
or, in the extreme case, a high pitched whine or static manifests after
a few hours of use, and recharging the cells eliminates these effects.
Where do I get replacement batteries / Can I buy
replacement batteries off the shelf?
The dAck! supply is in the form of a quick-release battery pack
available from Ack! Industries. Because the packs have some protection
circuitry built in and incorporate quick-release wiring, we do not
recommend that you try to source batteries yourself.