Top view, B+ fuse mdl 1/4 (underneath) – Manley STINGRAY original version rev.2 6/2005 - 9/2009 MSTX User Manual
Page 10
1
1
2
3
4
4
1
2
3
5
6
7
8
TP G
TP G
TP 5
TP 5
TP 6
TP 6
TP 7
TP 7
TP 8
TP 8
BIAS TRIMS
BIAS TRIMS ADJUST FOR 250 mV DC
ADJUST FOR 250 mV DC WITH
WITH NO SIGNAL
NO SIGNAL
SPEAKERS
SP
EA
KE
R
S
SPEAKERS
SP
EA
KE
R
S
5
6
7
8
TP 1
TP 1
TP 2
TP 2
TP 3
TP 3
TP 4
TP 4
CD
C
D
VIDEO
VID
EO
TUNER
TU
N
ER
AUX
AU
X
CD
C
D
VIDEO
VID
EO
TUNER
TU
N
ER
AUX
AU
X
AUX
AU
X
TUNER
TU
N
ER
VIDEO
VI
D
EO
CD
C
D
AUX
AU
X
TUNER
TU
N
ER
VIDEO
VI
D
EO
CD
C
D
VOLUME
VOLUME
BALANCE
BALANCE
PHONE (909) 627-4256
PH
ON
E (
90
9)
62
7-4
25
6
FAX
FA
X
(909) 628-2482
(9
09
) 6
28
-2
48
2
se
rv
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ma
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yla
bs
.c
om
OFF /
OF
F /
ON
ON
POWER
PO
WE
R
IEC MAINS
IE
C M
AIN
S
FUSE 3 AMP
FU
SE
3
A
MP
SLO-BLO
SL
O-B
LO
REPLACE FUSE ONLY
RE
PL
AC
E F
US
E O
NLY
WITH THE SAME TYPE
WIT
H T
HE
S
AM
E T
YP
E
AND VALUE
AN
D V
AL
UE
CAUTION: DO NOT OPEN,
CA
UT
IO
N:
DO
N
OT
O
PE
N,
HIGH
HIG
HVOL
TAGE.
VO
LTA
GE
.
REFER ALL SER
VICING T
O
RE
FE
R A
LL
S
ER
VIC
IN
G T
O
QUALIFIED PERSONNEL
QU
AL
IF
IE
D P
ER
SO
NN
EL
WARNING: T
O REDUCE THE
WA
RN
IN
G:
TO
R
ED
UC
E T
HE
RISK OF FIRE OR ELECTRIC
RIS
K O
F F
IR
E O
R E
LE
CT
RIC
SHOCK DO NOT EXPOSE
TO
SH
OC
K D
O N
OT
E
XP
OS
E T
O
RAIN OR MOISTURE
RA
IN
O
R M
OIS
TU
RE
MANLEY LABS
MA
NL
EY
L
AB
S
13880 MAGNOLIA A
VE
13
88
0 M
AG
NO
LIA
A
VE
CHINO, CA 91710 USA
CH
IN
O,
CA
9
17
10
U
SA
BIAS TEST
POINTS
BIA
S T
ES
T P
O
IN
TS
BIAS TEST
POINTS
BI
AS
T
ES
T
PO
IN
TS
GROUND for
GROUND for BIAS
BIAS
MEASUREMENTS
MEASUREMENTS
(BLACK LEAD GOES HERE)
(BLACK LEAD GOES HERE)
FUSE
FUSE
MAINS
MAINS
ON/OFF
ON/OFF
BIAS TRIMS
BIAS TRIMS
TRIODE/UL
TR
IO
D
E/
U
L
LOOP
ACTIVE/BYP
ASS
LO
O
P
AC
TI
VE
/B
YP
AS
S
SUB OUT
SU
B
O
U
T
LOOP
RETURN
LO
O
P
R
ET
U
R
N
REC OUT
/ LOOP
SEND
R
EC
O
U
T
/ L
O
O
P
SE
N
D
TRIODE/UL
TR
IO
D
E/
U
L
LOOP
ACTIVE/BYP
ASS
LO
O
P
AC
TI
VE
/B
YP
AS
S
SUB OUT
SU
B
O
U
T
LOOP
RETURN
LO
O
P
R
ET
U
R
N
REC OUT
/ LOOP
SEND
R
EC
O
U
T
/ L
O
O
P
SE
N
D
-
+
-
+
6414
6414
6414
6414
12AT7
12AT7
12AT7
12AT7
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
EL84
TOP VIEW
TUBE LOCATIONS - See the diagram above for the proper tube locations. Power
should be unplugged and the tubes cool before handling them. We label the tube
sockets, test points and trimmers to help. It is possible to put tubes in wrong if you
bend the pins - not good. On this diagram we added dashed lines to further clarify
which test points are associated with which tube and which trimmer but they are
numbered right on the chassis.
Refer to pages page 16 to 18 if you are unsure about replacing tubes and setting the
bias. A full description is given.
Once that you've learned a bit about setting bias, we provide a bias trim pot and test
point for each tube that should be referred to ground or TPG (The butt of the
Stingray logo). Aim for .25V DC volts or 250 mV DC. All of the important info is
silk-screened on the chassis.
Notice that there are two fuses for the B+. These are 250 mA SLO-BLO ( MDL 1/4)
types. They are supposed to blow with some types of tube shorts and prevent
damage to the amps. ALWAYS let the amps sit unpowered for at least 20 minutes
before attempting to check them out - SHOCK HAZARD - there can be very high
volts here until the power supply capacitors discharge. See page 8 for details.
10
B+ FUSE
MDL 1/4
(underneath)