Instruction Manual for DAC3 HGC and DAC3 L with 2.X Firmware Page 34
Benchmark Technologies
Hybrid Gain Control™
HGC™ is Benchmark's unique Hybrid Gain
Control™ system. The DAC3 combines active
analog gain control, passive low-impedance
attenuators, a 32-bit digital gain control, and
a servo-driven volume control.
All inputs are controlled by the rotary volume
control. This volume control moves in
response to commands from the remote
control. Analog inputs are never converted to
digital, and digital inputs never pass through
an analog potentiometer. Digital inputs are
precisely controlled in the 32-bit DSP system.
The DSP system preserves precise L/R
balance, and precise stereo imaging, while
avoiding any source of noise and distortion.
Benchmark's unique passive output
attenuators provide distortion-free gain
reduction without reducing the dynamic range
of the converter. The attenuators optimize the
gain staging between the DAC3 and the
power amplifier. This optimization is
absolutely essential for maximizing the
dynamic range of the entire playback system.
Much of the success of the DAC1 and DAC2
converters can be attributed to the passive
output attenuators. Musical details can be
obscured by system noise whenever a
preamplifier and power amplifier are
improperly matched. The HGC™ system in
your DAC3 will make full use of your power
amplifier's dynamic range. Experience newly
revealed details in your favorite recordings.
The front-panel volume control is a servo-
driven gain control built around a custom-
made Alps potentiometer. The custom Alps
pot is equipped with a remote-controllable
motor drive.
This potentiometer is equipped with a clutch
which prevents damage from overriding the
motor drive. If the pot is driven beyond the
end of its range, it will not damage the motor.
Also, if the pot is manually overridden, it will
not damage the motor.
Native DSD Conversion
The digital coaxial inputs and the USB Audio
2.0 input on the DAC3 support native DSD
conversion. DoP 1.1 DSD encapsulation is
automatically detected on all digital inputs.
The system seamlessly switches to native
DSD conversion when DoP is detected. DoP
1.1 DSD encapsulation is supported by many
media players. DSD downloads are now
available from several sources.
Visit our website for an up-to-date list of DSD
and PCM high resolution download sites.
High Headroom DSP
All of the digital processing in the DAC3 is
designed with a headroom of 3.5 dB above 0
dBFS. A sinusoid that just reaches the
maximum positive and negative digital codes
has a level of 0 dBFS. If the peaks of the
sinusoid occur between samples, higher
signals can be captured without clipping. For
a pure tone, the maximum intersample peak
that can be represented by a PCM system is
+3.01 dBFS.
Benchmark's high-headroom DSP can handle
intersample peaks without overloading or
clipping. Intersample peaks are cleanly
rendered by the DAC3 and are delivered to
the analog outputs without clipping or
distortion. Very few D/A converters can
make this claim!
In most D/A conversion systems, intersample
peaks cause overloading of the upsampling
interpolators and digital filters that are found
in all sigma-delta converters. When overloads
occur, bursts of non-harmonic distortion are
produced. These bursts of high-frequency
distortion may occur many times per second
and may add a false brightness and
harshness to the sound. This defect impacts
PCM formats but does not impact 1-bit DSD
formats. The absence of intersample clipping
may explain some people's preference for
DSD. The DAC3 delivers clean PCM
conversion that meets or exceeds the clarity
of DSD.
To Next Page
Loading...
