Benchmark DAC3 HGC - Headphone Jacks

Instruction Manual for DAC3 HGC and DAC3 L with 2.X Firmware Page 13
Headphone Jacks
(DAC3 HGC only)
The left-hand jack
mutes the XLR and
RCA outputs.
The right-hand jack
keeps all outputs
active.
Headphone Mute Switch
The left-hand headphone jack includes a
switch that mutes the main analog outputs
(XLR and RCA) when a headphone plug is
inserted. This feature allows the listener to
switch from loudspeaker to headphone
playback seamlessly. This Auto-Mute feature
can be disabled with internal jumpers.
Note: Instructions for setting the Auto-Mute
jumpers can be found in the
Internal
Settings section of this manual (Page 28).
Tip: Use the left-hand jack to mute your
loudspeaker system. Use the right-hand jack
to keep all outputs active.
Driving Two Sets of Headphones
The HPA2™ is specifically designed with
enough power to drive two sets of
headphones.
Tip: The Volume Control simultaneously
adjusts the level for both jacks. If two
listeners will be simultaneously using the
headphone outputs, we recommend using
headphones with identical or similar voltage
sensitivities.
HPA2
TM
Headphone Power Amplifier
The headphone jacks are driven by
Benchmark's HPA2™ headphone power
amplifier. This small and very clean power
amplifier can deliver the current and voltage
required by some of the most demanding
headphones. The output impedance of the
HPA2™ is very close to 0 Ohms. This low
output impedance delivers a high damping
factor so that the amplifier can maintain
precise control over the headphone
transducers.
Headphone voltage sensitivities vary
substantially, so we have equipped the
HPA2™ with Gain-Range jumpers that can
be used to customize the headphone amplifier
to your favorite headphones. If you find that
you have too much output (volume control
set below 11 o'clock), there are internal
jumpers that can be adjusted to decrease the
output level by 10 dB or 20 dB relative to the
factory default setting.
Note: Instructions for setting the headphone
Gain-Range jumpers can be found in the
Internal Settings section of this manual.
Tip: For optimal performance, the headphone
Gain-Range jumpers should be set so that
comfortable listening levels occur when the
volume control is set above the 11 o'clock
position.