Electrical Measuring Conditions; Frequency Characteristics; Noise Level; Total Harmonic Distortion - Yamaha DME24N Service Manual

2-1-2-2 Electrical Measuring Conditions

Unless otherwise specified, the following conditions
should be met.
· 0dBu=0.775Vrms.
· MIN ("0" display position) for PHONES LEVEL setting.
· CH 1-8 OUT: 600Ω for analog output load.
· Do not connect the USB cable in the front of the main
unit when the ANALOG IN /OUT characteristic test
is carried out. Also, do not connect loop back jigs in
the back side of the main unit (BNC cable, REMOTE
jig, and MIDI cable).
2-1-2-3 Analog CH 1-8 IN → CH 1-8 OUT
(Inspections at WORD CLOCK "INT 96kHz")
Measuring Points···Analog CH 1-8 OUT
Measuring Method···Input an analog signal from CHn
input, and measure an output signal from CHn
output.(n=1~8)
Enter the Diag Mode, select the "TEST CASE:#x"
depending on the measuring item (see 2-1-2-1 Diag
Mode Settings), and press "ENTER".
a. Characteristic Test at HA-GAIN: MIN (HA-GAIN
setting = "10dBu")
Select the "TEST CASE:#1" (see 2-1-2-1 Diag Mode
Settings), and press "ENTER".
q Voltage Gain
Input Frequency Input Level Specified Output Level Permissible range
1kHz +10dBu
w Frequency Characteristics
Measuring Method···Set 1kHz as datum, and measure
a relative value for each input frequency.
Input Frequency Input Level Specified Output Level Permissible range
20Hz +10dBu
40kHz +10dBu
e Noise Level
Measuring Method···Terminate the CHn input with
150Ω. Measure noise levels output from the CHn
output. (n =1~8)
Permissible range
-82dBu or below
r Level Difference between CHs
The range of gain differences between CHs (CH 1-8)
measured in the above steps q and w will be defined
as follows.
Permissible range
Within 1dB
+4dBu +4±2dBu
+4dBu -1.0~+0.5dB
+4dBu -1.0~+0.5dB
t Crosstalk between Adjacent CHs
t -1. Crosstalk from Odd CHn to Even CHn+1
(n=1,3,5,7)
Measuring Method···Terminate CHn++1 input with
150Ω. Input the following signal into the CHn input,
and measure leakage signal level at CHn+1
output.(n=1,3,5,7)
Input Frequency Input Level
(Odd Channel) (Reference Value)
1kHz +28dBu
t - 2. Crosstalk from Even CHn to Odd CHn-
1(n=2,4,6,8)
Measuring Method···Terminate CHn-1 input with
150Ω. Input the following signal into the CHn input,
and measure leakage signal level at CHn-1
output.(n=2,4,6,8)
Input Frequency Input Level
(even Channel) (Reference Value)
1kHz +28dBu
y Maximum Output
Input Frequency Input Level Specified Output Level Permissible range
(Reference Value)
1kHz +30dBu
u Total Harmonic Distortion
Input Frequency Input Level
(Reference Value)
1kHz +20dBu
20Hz +20dBu
40kHz +20dBu
b. Characteristic Test at HA-GAIN: MAX (HA-GAIN
setting = "-60dBu")
Press "ENTER" to return "TEST CASE No. Selection
Mode" for a time.
Select the "TEST CASE:#2" (see 2-1-2-1 Diag Mode
Settings), and press "ENTER".
q Voltage Gain
Input Frequency Input Level Specified Output Level
1kHz -60dBu
w Frequency Characteristics
Measuring Method···Set 1kHz as datum, and measure
a relative value for each input frequency.
Input Frequency Input Level Specified Output Level
20Hz -60dBu
40kHz -60dBu
DME24N/DME64N
Output Level Permissible range
(even Channel)
+22dBu -58dBu or below
Output Level Permissible range
(Odd Channel)
+22dBu -58dBu or below
(Distortion factor)
+24dBu 0.01% or below
Output Level Permissible range
+14dBu 0.01% or below
+14dBu 0.01% or below
+14dBu 0.02% or below
Permissible range
+4dBu +4±2dBu
Permissible range
+4dBu -1.0~+0.5dB
+4dBu -1.0~+0.5dB
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