Denon DN-780R Service Manual page 12

5. Recording System Adjustment
5-1. Adjusting recording/playback comprehensive
frequency characteristics.
(1) Load a test tape TDK AC-514.
Record with a -20 dB 1 kHz input level signal into
the LINE IN terminal and playback.
(2) Make a sample recording using a 12 kHz input
signal and playback this recording. Adjust (left
channel) and (right channel) so that they conform
to the following specified characteristics.
(db)
+6
+5
+4
+3
+2
+1
0
−1
−2
−3
−4
−5
−6
20 50
5-2. Recording/Playback Level Adjustment
(1) Load the test tape TDK AC-514. Make a sample
recording with the 1 kHz (-20 dB) signal and play
this section back.
(2) Adjust (Lch) and (Rch) so that the output from
LINE OUT terminal is the same as the output at
recording monitoring time.
5-3. Dolby C recording and playback comprehensive
frequency characteristics verification
(1) Set the Dolby NR switch at "C" position.
(2) Use a test tape TDK AC-514 and record and
playback as in item 5-1 to verity that they satisfy
the characteristics standards.
(db)
+6
+5
+4
+3
+2
+1
0
−1
−2
−3
−4
−5
−6
20 50
Record/Playback Overall Frequency Response
100 200 500
Dolby C Record/Playback Overall Frequency Response
100 200 500
LINE IN
ATT
LINE OUT
V.V
Frequency Responce
Adjusting volume number
DECK L/R
L VR-105
A
R VR-106
L VR-405
B
R VR-406
1 k 2 k 5 k
Tape : AC-514
Dolby NR : Off
: −20 dB From Dolby Level
Level
R/P Level Adjustment
DECK L/R Adjusting volume number
L VR-103
A
R VR-104
L VR-403
B
R VR-404
1 k 2 k 5 k
Tape : AC-514
Dolby NR : On C
: −20 dB From Dolby Level
Level
DN-780R
REC Amp
PB Amp
10 k 12 k 20 k (Hz)
20 k (Hz)
10 k 12 k
12