Bridge Mode; Gain; Frequency Response; Total Harmonic Distortion - Yamaha PC4800N Service Manual

PC9500N/PC4800N
3.

BRIDGE mode

3.1 Preparation
Input attenuator
Input terminal
MODE switch
HPF
Output terminal
DATA port
AMP ID switch
Load resistor
Connection of measuring instrument
3.2 Inspection

3.2.1 Gain

Feed 1kHz, -10.0dB sine wave to the input terminal and check that +22.1±1.0dB output voltage is obtained.

3.2.2 Frequency response

Feed 20Hz, 1kHz, 20kHz, -10dB sine wave to the input terminal and measure the output voltage at each time, and then check
that the measured voltage at 20Hz is within 0.0±0.5dB and that at 20kHz is within -0.5±0.5dB as compared with the output
voltage at 1kHz.

3.2.3 Total harmonic distortion

Feed 1kHz high grade sine wave to the input terminal and check that the total harmonic distortion is 1% or less when the output
given in the table below is obtained. Make sure to finish this check within 30 seconds.
PC9500N
41.2dB
4. Factory setting
Input attenuator: ∞(turned counterclockwise fully)
HPF: OFF
MODE: STEREO
AMP ID: OFF
5. Others
0dB=0.775V
Use a DIN audio filter when measuring the noise level,.
36
Operation for Ach only. MAX.
XLR-3-31 type
BRIDGE
OFF
Ach + and Bch+ used.
Unused
1,2,4,8,16,T OFF
8Ω+8Ω non-inductive resistance, power capacity 1kW or more
Connect to the mid-point of load resistor with the ground floated.
PC4800N
38.2dB