Studer A1 - A5: Input Common Mode Rejection Ratio (CMMR)

A Series Active Monitor Speakers
Date printed: 29.02.00 Service E4/27
4.5.1.6 A5: Input Common Mode Rejection Ratio (CMRR)
• Connect the generator in common mode to the input – i.e. “hot” generator
output to both input terminals no. 2 (+) and 3 (–), “cold” generator output
to input terminal no. 1 (GND).
Steps Generator Measurement
No. Description Id Value Test pos. Type Value Limits
1 CMRR 50 Hz G1 0 dBV/50 Hz/sine wave M1 Level < –60 dBV
2 CMRR 1 kHz G1 0 dBV/1 kHz/sine wave M1 Level < –60 dBV
3 CMRR 10 kHz G1 0 dBV/10 kHz/sine wave M1 Level < –40 dBV
Common mode rejection
–100
0
–90
–80
–70
–60
–50
–40
–30
–20
–10
[dBV]
20
20 k
50 100 200 500 1 k 2 k 5 k 10 k
[Hz]