Benchmark DAC3 HGC - Page 56

Instruction Manual for DAC3 HGC and DAC3 L with 2.X Firmware Page 56
Graph 10 - Headphone Amplifier into 300 Ohms – THD+N versus Power
This plot shows the THD+N performance of the headphone outputs when driving a typical 300-Ohm
load. Note that the THD+N performance of the headphone outputs approaches that of the balanced
outputs (-110 dB at 20 mW). Benchmark's HPA2™ headphone amplifier can cleanly deliver 21.5
dBu (9.2 Vrms) into a 300-Ohm load.
This graph shows that the HPA2™ has the voltage required to drive high-impedance headphones.
The following graph shows that the HPA2™ has the power required to drive low-impedance
headphones. In either case, the near 0-Ohm output impedance provides outstanding control and
damping of the headphone drivers.
The HPA2™ includes 3 jumper-programmable gain ranges that can be configured to match the
voltage sensitivity of your favorite headphones. The gain-range settings do not change the output
impedance or the THD of the headphone amplifier.
Audio Precision
DAC3 - Headphone Amplifier - THD+N vs Power at 1 KHZ (w/20 kHz LPF unweighted)
Headphone outputs into 300 Ohms, both channels driven
DAC3 - HEADPHONE - THD+N vs Power - 300 Ohm Load.at27
ColorSweep
Trace Line Style Thick Data Axis Comment Cursor1 Cursor2
1 1
Red Solid
4 Anlr.THD+N Ratio
Left *-80.976 dB
*-102.254 dB
-120
+0
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
-80.976
-102.254
d
B
10u 300m 20u 50u 100u 200u 500u 1m 2m 5m 10m 20m 50m 100m
10.11u 278.8m
W
dx=278.8 mW
dy=-21.278 dB