PRE420 Instruction Manual – rev. E
Page 20
THD+N vs. Frequency
Measurement Bandwidth = 10Hz to 80 kHz, Gain = 30 to 60 dB, Output Level = +4 dBu
Audio Precision
02/21/07 09:56:41
PRE420 - THD+N vs Frequency at 60 dB Gain, BW=80 kHz
Color
Sweep
Trace
Line Style
Thick
Data
Axis
Comment
1
1
Red
Solid
4
Anlr.THD+N Ratio
Left
60 dB Gain (top trace)
2
1
Magenta
Solid
4
Anlr.THD+N Ratio
Left
50 dB Gain
3
1
Blue
Solid
4
Anlr.THD+N Ratio
Left
40 dB Gain
4
1
Green
Solid
4
Anlr.THD+N Ratio
Left
30 dB Gain (bottom trace)
0.0001
0.01
0.0002
0.0005
0.001
0.002
0.005
%
-120
-80
-118
-116
-114
-112
-110
-108
-106
-104
-102
-100
-98
-96
-94
-92
-90
-88
-86
-84
-82
d
B
20
80k
50
100
200
500
1k
2k
5k
10k
20k
50k
Hz
This graph shows that THD+N does not rise with frequency – even at maximum gain.
