Benchmark DAC2 Series - Page 43

DAC2 Series Instruction Manual Rev C Page 43
A
udio Precision DAC2 - FFT 1 kHz, 0 dBr = 0 dBFS = 23 dBu
DAC2 - FFT 1 kHz.at27
ColorSweep Trace Line Style Thick Data Axis Comment Cursor1 Cursor2
1 1 Green Solid 4 Fft.Ch.1 Ampl Left *-115.268 dBr *-128.290 dBr
1 2 Red Solid 4 Fft.Ch.2 Ampl Right -115.954 dBr A -130.429 dBr A
-160
+0
-140
-120
-100
-80
-60
-40
-20
d
B
r
A
-160
+0
-140
-120
-100
-80
-60
-40
-20
-115.268
-128.29
d
B
r
A
0 3.2k200 400 600 800 1k 1.2k 1.4k 1.6k 1.8k 2k 2.2k 2.4k 2.6k 2.8k 3k
2.00391k 2.99961k
Hz
dx=.995695 kHz d
y
=-13.022 dB
Graph Plot 4 - FFT 1 kHz
The 1 kHz FFT analysis demonstrates the low harmonic distortion of the DAC2. Second harmonic
distortion (2 kHz) measures about -115 dB, while 3rd harmonic distortion measures -128 to -130
dB.
The rise at 0 Hz is normal in an FFT analysis and is not an indication of noise. This 32k point FFT
analysis uses a Blackman-Harris window with 16x power averaging, and spans a frequency range
of DC to 32 kHz.