PRE420 Instruction Manual – rev. E
Page 23
Noise Spectrum
32k B-H FFT, Gain = 60 dB, 0 dBr = 0 dBu at input
Audio Precision
02/19/07 11:27:19
Noise Spectrum, Gain = 60 dB, 0 dBr = 0 dBu at Input
Color
Sweep
Trace
Line Style
Thick
Data
Axis
Comment
Cursor1
Cursor2
1
1
Red
Solid
4
Fft.Ch.1 Ampl
Left
*-145.066 dBr A
*-149.014 dBr A
-200
+0
-190
-180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
-145.066
-149.014
d
B
r
A
10
30k
20
50
100
200
500
1k
2k
5k
10k
20k
59.6606
180.657
Hz
dx=120.996 Hz
dy=-3.948 dB
The above graph demonstrates that the PRE420 is free of hum and noise. The highest tone is 60-
Hz line-related hum and is at a level equivalent to an input level of -145 dBu. 180-Hz hum is at an
equivalent input level of -149 dBu.
