Lab.gruppen PLM 20K44 Operation Manual page 78

10. Application Guide
Figure 10.3 illustrates how to achieve the lowest possible output noise, although this is not a recommended
configuration.
• Input Clip: 0 dBFS
• Amp Gain: 22 dB
• SNR: 114.8 dB
• Absolute Noise Floor: -71.9 dBu
100,0
50,0
0,0
-50,0
-100,0
-150,0
Analog AES Input
-200,0
-250,0
Table 10.3: Digital Input Optimized for Minimum Noise - Not Recommended
The improvement in noise performance (at the cost of losing headroom and compression features) is only 0.6 dB;
it is therefore not recommended to optimize performance in this manner.
10.4.3.2. Analog Input Gain Structure Examples
Figure 10.4 illustrates how to minimize absolute noise while limiting the available SPL. Input Clip: 12 dBu
• Amp Gain: 22 dB
• SNR: 105.5 dB
• Absolute Noise Floor: -71.5 dBu
• SPL is limited to -8.9 dB relative to clip in this minimum absolute noise level example
60,0
40,0
20,0
0,0
-20,0
-40,0
-60,0
-80,0
-100,0
-120,0
-140,0
Analog AES Input
Table 10.4: Analog: Low Noise with Limited Output (Low Input / Low SPL)
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PLM+ SERIES Operation Manual rev 1.0.0
Input Mixer Module In Module Out Amp
Input Mixer Module In Module Out Amp
Attenuation Analog Ref Amp Gain ISVPL
Attenuation Analog Ref Amp Gain ISVPL
Clip
Nominal
Noise
Output
Clip
Nominal
Noise
Output