Instruction manual

DAC2 DX Instruction Manual Rev A Page 26
XLR Output Pads
The XLR outputs are equipped with low-impedance passive pads that may be used to reduce the
output levels while preserving the full dynamic range of the DAC2 DX. The unit ships with the pads
disabled (0 dB setting).
When the output pads are enabled, the output impedance changes slightly, and the maximum
allowable cable length should be reduced as shown in Table 1 (assuming 32 pF/foot and a
maximum allowable loss of 0.1 dB at 20 kHz).
TIP: To set the XLR outputs to typical
professional studio levels, set the pads to 0 dB.
For most home installations, set the pads to 10
dB or 20 dB. Use the 0 dB setting when driving
the Benchmark AHB2 power amplifier.
TIP: When directly driving power amplifiers and
powered speakers, start with the 10 dB pad
setting. If necessary, change the pads so that
normal listening levels are achieved with the
‘Volume Control’ above the 11 o’clock position.
Use the 0 dB setting with Benchmark's AHB2
power amplifier.
Table 1 - Cable Drive Capability
XLR Output Pad Selection (P8, P9, P10, and 11):
Four 6-pin headers (P8, P9, P10, and P11) allow
selection of the analog output level at the XLR jacks.
One pair of 6-pin headers controls the output level at
each XLR jack as follows:
 0 dB Attenuation = +24 dBu at full output
 -10 dB Attenuation = +14 dBu at full output
 -20 dB Attenuation = +4 dBu at full output
Figure 1 - 0 dB Pad Setting (Factory Default)
 0 dB - Jumper plug between pins 1 and 2 of each header – Factory Default
 -10 dB – Jumper plug between pins 3 and 4 of each header
 -20 dB – Jumper plug between pins 5 and 6 of each header
Balanced Output Drive Capability:
Attenuator Output
Maximum
Loss in dB
Setting (dB)
Impedance
Cable (ft) at 20 kHz
0 60 680 0.1
10 425 96 0.1
20 135 302 0.1
Unbalanced Output Drive Capability:
Output
Maximum
Loss in dB
Impedance
Cable (ft) at 20 kHz
30 1360 0.1