Akai GX-260D

VR2 5KB
LEVEL ADu. >)
VR5qa,b IOKB VU
HIGH SENSITIVITY
Vv.
Fig. 16. P.B. AMP. BLOCK DIAGRAM
REC, LEVEL ADJUST
1000Hz VR2 SOKA
REC. AMP. GAIN
VRI SKB
NORM VR3 10KB
REV. VR2 IOKB
REC, HEAD
NORM BIAS
VR2 70P MAX
AMP.
z, HIGH ee
ae se a pa eee |
Fig. 17 REC.AMP. BLOCK DIAGRAM
. RECORDING LEVEL ADJUSTMENT
(See Fig. 15)
1) Connect an Audio Frequency Oscillator to the
line input and connect a High Sensitivity V.T.V.M.
to the line output.
2) Set Tape Speed Selector to 7- 1/2 ips.
3) Load a Scotch 111 blank tape and set the Moni-
tor Switch to TAPE position.
4) Set recorder to recording mode, while depressing
both LEFT and RIGHT Recording Track Selec- —
tor Switches, and supply a 1,000 Hz sinewave
signal. to the line input from the audio frequency
oscillator.
5): Adjust Forward and Reverse Recording Capacitors
TC1l. and .TC2 to obtain maximum output on
all channels.
* In case of Frequency Response Bias adjustment
having been made prior to Recording Level
Adjustment, do not adjust these capacitors.
6) At this time, with forward and reverse recording
level adjustment volumes VR2 and VR3, adjust
each channel. to.1 dB lower than the channel
. discharging the smallest output.
7) Adjust Audio Frequency Oscillator output to
obtain a-line output level of 4 dB (O VU).
8) Set Monitor Switch to SOURCE position. and
adjust Rec. Amp. P.C. Board (ND-5038) Rec.
Amp. Gain Adjustment Volumes VRI1 (5 kB) to
obtain a 4 dB Line Output level on each channel.
NOTE
1) Because the recording level is very closely related
to the Frequency Response Adjustment (Section
5), re-confirm recording levels following frequency
response adjustment.
2) For O VU recording, it is necessary that the
microphone input level be about —70 dB follow-
ing Rec. Level Adjustment.
. RECORDING BIAS FREQUENCY MEAS-
URING METHOD AND ADJUSTMENT
1) Connect a Frequency Counter to OSC Circuit.
Set recorder to the REC mode, and take a fre-
quency counter reading at this time.
2) If the Frequency Counter indication is 100 +5
kHz, the recording bias frequency is correct.
Adjustment
..The recording bias frequency can be adjusted by
changing the value of OSC Circuit Condenser C27
(2,000P/250).