Teac V-2RX - DBX Performance; DBX Encoder Performance; DBX Decoder Performance

V-2RX/V-4RX
5-4 DBX PERFORMANCE
Note: Test this performance only
after you are sure ihat the
“5-6 DBX PCB ADJUST-
MENT?” is correct.
DECK settings:
LEVEL cont.: OFF (depressed)
MONITOR sw
(V-2RX only): TAPE
RECORD cont.: Specified position (item 7)
NR SYSTEM sw: NR-
BIAS FINE cont.
(V-2RX only): O (center detent position)
OUTPUT cont.: MAX
ITEM
SETTING
ADJUST
(or CHECK)
INPUT SIGNAL
21.Encoding level
REC/PAUSE mode
LINE IN:
400 Hz/~14.5 dB
(146 mv)
TEAC test tapes:
MTT-5072: For METAL recore’ test
MTT-5061: For Co (CrO,,) retard test
MTT-501: For NORMAL retard test
MEASURING
POINT: RESULT REMARKS
TP51/TP61 on DBX
PCB:
-8.2 dB (300 mV)
If, in the above step, the RESULT is out of specification, correct using the
RECORD control so that the correct value is obtained when the control is
in the specified position (item 7).
LINE IN: TP52/TP62 on DBX *1 Reference 1
REC/PAUSE mode 400 Hz/-14.5 dB*’ | R52/R62 PCB: *2 Reference 2
(146 mV) ~-8.2 dB** (300 mv)
TP52/TP62 on DBX
LINE IN: PCB:
100 Hz/-14.5 dB Check +0.5 dB +1 dB
22. Encoding single (146 mV) against Ref. 2
frequency
REC/PAUSE
mode
(283
mV
~
357
mV)
response
TP52/TP62
on
DBX
PCB:
LINE IN:
oo Check -2.8 dB +1 dB
10 kHz/-14.5 dB against Ref. 2
(194 mV ~ 244 mV)
TP52/TP62 on DBX
LINE IN: PCB: *3 60 dB
400 Hz/-74.5 dB*? | Check -30 dB +0.5 dB against Ref. 1
(146
nV)
against
Ref,
2
9
:
23.Encodin
(8.96
mV
~
10.1
mV)
“operation
level
REC/PAUSE
mode
TP52/TP62
on
DBX
LINE IN: PCB: *4 490 dB
400 Hz/+5.5 dB** Check +10 dB +0.5 dB against Ref. 1
(1.46 V) against Ref, 2 9 ;
me
_|
(0.896 V ~ 1.01 V)
Record a 400 Hz signal with NR SYSTEM switch OUT. Rewind and play the
recorded portion. Note the off-the-tape level from OUTPUT
above process with NR SYSTEM switch set to NR- . Note the off-the-tape
(1). Repeat the
level ..... (2). Compare the difference between (1) and (2). On V-2RX (only),
if +1 dB or more, correct by R54/R64 using (1) as Reference.
REC/PLAY | NR LINE IN: OUTPUT:
24.
Decoding
level
mode
SYSTEM:
400
Hz/-14.5
dB
Check
Note
the
off-the-
*5
Reference
3
TAPE: OUT (146 mV) tape level ..... oe
METAL OUTPUT:
nee
NR
V-2RX:
5
.
LINE
IN:
Check
+1
dB
against
Ref.
3
«6
\/.
5072
Re
eal
400
Hz/-14.5
dB
|
(R54/R64**)
|
V-4RX:
WES
OY
+1.5 dB against
Ref. 3
REC/PLAY mode
Measure the off-the-tape
level
feeds sw METAL
Tape: MTT-5072 ,
ner
baa
OUTPUT:
25.
Distortion
Bhai
sw:
Co
(CrO,)
400
Hz/-12
dB
Check
1.0%
or
less
Tape: MTT-5061 (195 mV) on
oe sw: NORMAL
Tape: MTT-501
LINE IN: ‘i
,
Z
400
Hz/-9
dB
;
Ratso
of
1
kHz
26.
Signal-to-noise
Same
as
above
(275
mV)
Check
OUTST
output
(-3.5
dB)
ratio
12
1
No signal
to n Oise
65 dB min. ratio
ren