Tascam 388 Studio 8 - Encoder

1"6-5. Encoder
Apply High signal to J111-2 to actívate DBX
Encode mode.
A. RMS Symmetry Adjustment (Connection: Fig.
1 -0-2)
1. Apply a 100 Hz, 300 mV signa! to J111-3
terminal. ,
2. Check for olean 200 Hz sinewave at TP01 (see
Fjg.s 1-6-5& 1-6-6).
B. VCA Symmetry Adjustment (Connection: Fig.
1-6-4)
1. Apply a staircase wave signa! to TP01, and a
traingle wave signal to the horizontal input
terminal on the oscilloscope.
2. Shortcircuit between J111-3 and J111-4.
3. Confirm that J110-5 supplies a relatively
horizontal line on the oscilloscope
(leve! deviation: 10 mV or less).
C.Encoding Leve! (Connection: Fig. 1-6-2)
1. Apply a 1kHz, 300 mV signal to J111-3
terminal.
2. Adjust R108 for a -10 dB reading at J110-3
terminal.
D.Frequency Response (Connection: Fig. 1-6-2)
1. Vary the signal frequency to 50 Hz (300 mV)
and then to 10 kHz (300 mV).
2. Read the output level at the J110-5 terminal
for each frequency. The output level should
be within the following limits with reference
to level at 1 kHz.
50 Hz :-2.5 dB ±1 dB (213 mV to 240 mV)
10 kHz: -4.8 dB ±1 dB (166 mV to 186 mV)
E. Release Rate Check (Conenction: Fig. 1-6-3)
1. Apply a 1 kHz tone burst wave signal with
8 cycles on and 128 cycles off.
2. Confirm that release rate is less than 750 mV
±10%.
F. Encode EffectCheck (Connection;
1
1 kHz, -70 dB signal
Fig
to
1-6-2)
J111-3
Apply a
terminal.
Confirm that the level at J110-3 terminal is
-40 dB ±0.5 dB (i.e., -30 dB against -10 dB
(300 mV) reference level)
Apply a 1kHz, -HOdB signal to J111-3
terminal.
Confirm that the level at J110-3 terminal is
O dB ±1 dB (i.e., -t-10 dB against -10 dB
reference level).
G.Other Channeis
Repeat procedures for channeis 2 through 8
using the following adjustment points and
input/output termináis.
Channel
Decode mode
H signal
Input Output Test Point
Adjustment Point
RMS
VCA
Level
ch1/ch5
jni-2 Jlll-3 jno-3 TP01
- -
R108
ch2/ch6
J211 2
J2133 J210-3
TP02
-
-
R208
ch3/ch7
J311 2 J311-3
J310-3
TP03
-
-
R308
ch4/ch8 J411-2 J411-3
J410-3 TP04
-
R408
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