Fostex PH-50 User manual

PH-50
1
PH-50
Service Manual
Model
HeadphoneAmpDistributor

2
PH-50
SAFETY INSTRUCTIONS
Read instructions - All the safety and operating instruc-
tions should be read before the appliance is operated.
Retain instructions - The safety and operating instructions
should be retained for future reference.
Heed warnings - All warnings on the appliance and in the
operating instructions should be adhered to.
Follow instructions - All operating and use instructions
should be followed.
Water and Moisture - The appliance should not be used
near water - for example, near a bathtub, washbowl,
kitchen sink, laundry tub, in a wet basement, or near a
swimming pool, and the like.
Carts and Stands - The appliance should be used only
with a cart or stand that is recommended by the manufac-
turer.
An appliance and cart combination should be moved with
care. Quick stops, excessive force, and uneven surfaces
may cause the appliance and cart combination to over-
turn.
Wall or Ceiling Mounting - The appliance should be
mounted to a wall or ceiling only as recommended by the
manufacturer.
Ventilation - The appliance should be situated so that its
location or position does not interfere with its proper ven-
tilation. For example, the appliance should not be situ-
ated on a bed, sofa, rug, or similar surface that may block
the ventilation openings; or, placed in a built-in installa-
tion, such as a bookcase or cabinet that may impede the
flow of air through the ventilation openings.
Heat - The appliance should be situated away from heat
sources such as radiators, heat registers, stoves, or other
appliances (including amplifiers) that produce heat.
Power Sources - The appliance should be connected to a
power supply only of the type described in the operating
instructions or as marked on the appliance.
Grounding or Polarization - The precautions that should
be taken so that the grounding or polarization means of
an appliance is not defeated.
Power Cord Protection - Power supply cords should be
routed so that they are not likely to be walked on or
pinched by items placed upon or against them, paying
particular attention to cords at plugs, convenience recep-
tacles, and the point where they exit from the appliance.
Cleaning - The appliance should be cleaned only as rec-
ommended by the manufacturer.
Nonuse Periods - The power cord of the appliance should
be unplugged from the outlet when left unused for a long
period of time.
Object and Liquid Entry - Care should be taken so that
objects do not fall and liquids are not spilled into the en-
closure through openings.
Damage requiring Service - The appliance should be ser-
viced by qualified service personnel when:
A.
B.
C.
D.
E.
Servicing - The user should not attempt to service the ap-
pliance beyond that described in the operating instruc-
tions. All other servicing should be referred to qualified
service personnel.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PARTS INSIDE.
TO PREVENT ELECTRIC SHOCK, MATCH
WIDE BLADE OF PLUG TO WIDE SLOT,
FULLY INSERT.
POUR ÉVITER LES CHOCS ÉLECTRIQUES,
INTRODUIRE LA LAME LA PLUS LARGE DE
LA FICHE DANS LA BORNE CORRE-
SPONDANTE DE LA PRISE ET POUSSER
JUSQU' AU FOND.
CAUTION:
ATTENTION:
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and mainte-
nance (servicing) instructions in the literature
accompanying the appliance.
The lightening flash with arrowhead symbol,
within an equilateral triangle, is intended to
alert the user to the presence of uninsulated
“dangerous voltage” within the product's en-
closure that may be of sufficient magnitude to
constitute a risk of electric shock to persons.
“WARNING”
“TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOIS-
TURE.”
1.
2.
3.
4.
5.
6.
7.
8.
The power supply cord or the plug has been damaged;
or
Objects have fallen, or liquid has been spilled into the
appliance; or
The appliance has been exposed to rain; or
The appliance does not appear to operate normally or
exhibits a marked changed in performance; or
The appliance has been dropped, or the enclosure
damaged.
9.
10.
11.
12.
13.
14.
15.
16.
17.

PH-50
3
TABLE OF CONTENTS
1. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. CONTROLS, INDICATORS AND CONNECTORS . . . . . . . . . . . .
3. EXPLODED VIEW, PCB ASSEMBLY AND PARTS LIST . . . . . .
4. CIRCUIT & BLOCK DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . .
NOTES
* Parts List and circuit diagrams are given in this manual to assist the service technician in maintaining the Model PH-50.
* The following accessories are supplied with PH-50 as the standard accessories.
Owner's manual : 8288384000 (for export model)
Owner's manual : 8288385000 (for domestic model)
* Following is the packing material for the Model PH-50.
PACKING SIDE A PH-50 : 8228445000
CARTON BOX PH-50 : 8228721000
4
5
6
10
CAUTION
Parts marked with this sign are safety critical components. They must always be replaced with identical components.
Refer to the Fostex Parts List and ensure exact replacement.

4
PH-50
1. SPECIFICATIONS
INPUT SECTION
INPUT (Balanced)
Connector XLR ( Hot : Pin 2 ) / Stereo phone ( Hot : tip )
Input level +4dBu / -10dBV(switchable)
Impedance 10 kΩor more
INPUT (Unbalanced)
Connector RCA pin
Input level -10dBV
Impedance 10 kΩor more
CHANNEL INPUT
Connector RCA pin
Input level -10dBV
Impedance 10 kΩor more
AUX INPUT
Connector RCA pin
level -10dBV
Impedance 10 kΩor more
OUTPUT SECTION
PHONES 1-5
Connector Stereo phone
Max. Output Level 500 mW or more ( 32 Ω load, Distortion 3.0 % or less )
Load Impedance 8 ~ 32 Ω
Frequency Response 30 ~ 20 kHz ± 2dB ( 32 Ω load, 1kHz, 200 mW )
S/N -65dBV or less (DIN AUDIO, OUTPUT VR : MIN)
-80dBV or less ( IHF-A, OUTPUT VR : MIN)
Distortion 0.1 % or less ( 32 Ω load, 1kHz, 200 mW )
CASCADE OUT
Connector RCA pin
Output level -10dBV ± 3dB (INPUT VR : CAL )
Frequency Response 30 ~ 20 kHz ± 1dB
S/N -85dBV or less (DIN AUDIO, OUTPUT VR : MIN)
-90dBV or less ( IHF-A, OUTPUT VR : MIN)
Distortion 0.05 % or less ( 1kHz, -10dBV )
Click Noise (Power on / off) -20dBVp-p or less (OUTPUT VR : MIN)
Shock Noise -40dBVp-p or less (Measure noise level when one side of appliance
is dropped 3 times from 5 cm height.)
Peak LED Indication +7dBV ± 3dB
GENERAL
Dimensions 210 (W) ×200 (D) ×43 (H) mm
Weight 1.9 kg
Power supply
JPN 100 VAC, 50/60 Hz
USA/CND 120 VAC, 60 Hz
EUR/UK 230 VAC, 50/60 Hz
Power consumption 8 W
* Specifications and appearance are subject to change without notice for product improvement.

PH-50
5
2. CONTROLS, INDICATORS & CONNECTORS
< Front Panel >
PH-50
HEADPHONE AMP DISTRIBUTOR
PEAK
CAL
PHONES
AUX IN
INPUT
MONOST
POWER
5
100
34521
5
100
5
100
5
100
5
100
5
100
5
100
1234
5678
< Rear Panel >
12345
LRL R L/MONO R
CASCADE OUT INPUT AUX IN
(-10dBV) (-10dBV) (-10dBV)
CHANNEL IN
(-10dBV)
+4dBu -10dBV
LR
RL
INPUT
(+4dBu/-10dBV) PHONEXLR HOT
COLD
GND
T2 R
S
3
1
910
11 12 13 14 15
9. Channel input jacks [CHANNEL IN 1-5]
10. Balanced input connector (XLR) [INPUT]
11. Cascade output jack [CASCADE OUT]
12. Unbalanced input jack [INPUT]
13. AUX input jacks [AUX IN]
14. Balanced input level selector switch [-4dBu/-10dBV]
15. Balanced input connector (Stereo phone) [INPUT]
1. Headphone output level control knob [PHONES 1-5]
2. AUX input level control knob [AUX IN]
3. Peak LED [PEAK]
4. Power LED [POWER]
5. Headphone jacks [PHONES 1-5]
6. Input image position selector switch [ST/MONO]
7. Input master level control knob [INPUT]
8. Power switch [POWER]

6
PH-50
BBT 3x6 BZn
B 3x6 CZn
BBT 3x8 BZn
BBT 3x8 BZn
BBT 3x6 BZn
BBT 3x8 BZn
BBT 3x6 BZn
BBT 3x6 BZn
BBT 3x6 BZn
BBT 3x6 BZn
Ref. No. Part No. Description
1 8221262000 CASE, COVER, PH-50
2 8221264000 PANEL, FRONT, PH-50
3 8274174000 PCB Assy, MAIN, PH-50
4 8650800000 CORD, AC, USA/CND
8650801000 CORD, AC, EUR
8650802000 CORD, AC, UK
8650803000 CORD, AC, JPN
5 8207000208 BUSHING, SR-4N-4
6 8218775001 INSULATION SHEET, PH-50
7 8228775002 INSULATION SHEET B, PH-50
3. EXPLODED VIEW, PCB ASSEMBLY AND PARTS LIST
PH-50 OVERALL EXPLODED VIEW & PARTS LIST
Ref. No. Part No. Description
8 8274175000 PCB Assy, VR, PH-50
9 8226198003 ROTARY, KNOB(C), G
10 8226198001 ROTARY, KNOB(A), R
11 8242256003 TRANS, POWER, 120V
8242256006 TRANS, POWER, 230V~
8242256010 TRANS, POWER, 100V
12 8221263000 CHASSIS, MAIN, PH-50
13 8253014007 SW, WL, PUSH, POWER, SDDLB-SPST
14 8207000318 PLASTY-FOOT, 3725
15 8226228000 BUTTON, PUSH, POWER

PH-50
7
PH-50 Parts List
• MAIN/VR PCBs
ICs
Ref. No. Part No. Description
U101~501 8236035803 IC, µPC4570HA
U102~502 8236046000 IC, NJM386BD
U152~552 8236046000 IC, NJM386BD
U601 8236035803 IC, µPC4570HA
U602 8236035803 IC, µPC4570HA
U605 8236035803 IC, µPC4570HA
U651 8236035803 IC, µPC4570HA
U701 8236035803 IC, µPC4570HA
U801 8236032005 IC, REGULATOR, NJM78M12FA
U802 8236034705 IC, REGULATOR, 79M12FA
TRANSISTORs
Ref. No. Part No. Description
Q601 8234108900 TR, 2SD1858, QR, T
Q602 8234108900 TR, 2SD1858, QR, T
Q603 8234108800 TR, 2SB1237, PQR, T
Q604 8234108900 TR, 2SD1858, QR, T
Q801 8234107600 TR, 2SC4549, NEC
DIODEs
Ref. No. Part No. Description
D601 8234106500 OPT, LED, RT3-222HCS
D602 8234500700 D, HT,1SS136
D603 8234500700 D, HT, 1SS136
D751 8234500700 D, HT, 1SS136
D752 8234106500 OPT, LED, RT3-222HCS
D753 8234500700 D, HT, 1SS136
D754 8234500700 D, HT, 1SS136
D801 8234108700 D, RB151
D802 8234106500 OPT, LED, RT3-222HCS
RESISTORs
Ref. No. Part No. Description
R101~501 8240284001 VR, RK09K120A1NA, 5KΩA x 2
R110~510 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R111~511 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R112~512 8230138104 HT, CARBON, 1/4W, 100K, 5%
R113~513 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R114~514 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R115~515 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R116~516 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R117~517 8230138100 HT, CARBON, 1/4W, 10Ω, 5%
R118~518 8230111568 H, METAL, 5.6Ω, 5%
R119~519 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R150~550 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R151~551 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R152~552 8230138104 HT, CARBON, 1/4W, 100KΩ, 5%
R153~553 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R154~554 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R155~555 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R156~556 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R157~557 8230138100 HT, CARBON, 1/4W, 10Ω, 5%
R158~558 8230111568 H, METAL, 5.6Ω, 5%
R159~559 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R601, 602 8240284001 VR, RK09K120A1NA, 5KΩA x 2
R610, 650 8230138104 HT, CARBON, 1/4W, 100KΩ, 5%
R611, 651 8230138103 HT,CARBON, 1/4W, 10KΩ, 5%
R612, 652 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R613, 653 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R614, 654 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R615, 655 8230138104 HT, CARBON, 1/4W, 100KΩ, 5%
R616, 656 8230138104 HT, CARBON, 1/4W, 100KΩ, 5%
R617, 657 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R618, 658 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R619, 659 8230138822 HT, CARBON, 1/4W, 8.2KΩ, 5%
R620, 660 8230138822 HT, CARBON, 1/4W, 8.2KΩ, 5%
R621, 661 8230138822 HT, CARBON, 1/4W, 8.2KΩ, 5%
R622, 662 8230138822 HT, CARBON, 1/4W, 8.2KΩ, 5%
R623, 663 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R624, 664 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R625, 665 8230138102 HT, CARBON, 1/4W, 1KΩ, 5%
R626, 666 8230138104 HT, CARBON, 1/4W, 100KΩ, 5%
R627, 667 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R628, 668 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R629, 669 8230138332 HT, CARBON, 1/4W, 3.3KΩ, 5%
R630, 670 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R631, 671 8230138103 HT, CARBON, 1/4W, 10KΩ, 5%
R632, 672 8230138393 HT, CARBON, 1/4W, 39KΩ, 5%
R633, 673 8230138101 HT, CARBON, 1/4W, 100Ω, 5%

8
PH-50
CAPACITORs
ALU = Electrolytic
CER = Ceramic type
PES = Mylar type
Ref. No. Part No. Description
C101~501 8232050100 CER, 50V, 10PF, +-.5PF, SL
C102~502 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C103~503 8232901102 PES, 50V, 0.001µF, 5%, AMZV
C104~504 8232143337 ALU, 16V, 330µF, 20%, SME-VB
C105~505 8232142476 ALU, 10V, 47µF, 20%, SME-VB
C107 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C108 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C109~509 8232901473 PES, 50V, 0.047µF, 5%, AMZV
C151~551 8232050100 CER, 50V, 10PF, +-.5PF, SL
C153~553 8232901102 PES, 50V, 0.001µF, 5%, AMZV
C154~554 8232143337 ALU, 16V, 330µF, 20%, SME-VB
C155~555 8232142476 ALU, 10V, 47µF, 20%, SME-VB
C159~559 8232901473 PES, 50V, 0.047µF, 5%, AMZV
C307 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C308 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C601, 651 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C602, 652 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C603, 653 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C604, 654 8232050101 CER, 50V, 100PF, 5%, SL
C605, 655 8232050101 CER, 50V, 100PF, 5%, SL
C606, 656 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C607, 657 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C608, 658 8232050100 CER, 50V, 10PF, +-.5PF, SL
C610, 660 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C611, 661 8232050100 CER, 50V, 10PF, +-.5PF, SL
C612, 662 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C614, 664 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C615, 665 8232050100 CER, 50V, 10PF, +-.5PF, SL
C617, 667 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C620 8232153225 ALU, 50V, 2.2µF, 20%, BP, SME-VB
C621 8232146225 ALU, 50V, 2.2µF, 20%, SME-VB
C622 8232146225 ALU, 50V, 2.2µF, 20%, SME-VB
C701~705 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C751~753 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C801 8232096108 ALU, 25V, 1000µF, 20%, SME-VB
C802 8232096338 ALU, 25V, 3300µF, 20%, SME
C803 8232096108 ALU, 25V, 1000µF, 20%, SME-VB
C804 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C805 8232804104 CER, 25V, 0.1µF, +80-20%,YF
C806 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C807 8232144226 ALU, 25V, 22µF, 20%, SME-VB
C808 8232901473 PES, 50V, 0.047µF, 5%, AMZV
C809 8232901473 PES, 50V, 0.047µF, 5%, AMZV
C810 8232096108 ALU, 25V, 1000µF, 20%, SME-VB
MISCELLANEOUS
Ref. No. Part No. Description
CN803 8745503003 CONN, XH 3P (87003048)
J101~601 8245337000 CONN, PHONE JACK, STEREO
J602 8245268002 CONN, PL, JACK, XLR31, NC3FAH2
J603 8245311004 CONN, RCA, 4P,YKC21-3084
J651 8245337000 CONN, PHONE JACK, STEREO
J652 8245268002 CONN, PL, JACK, XLR31, NC3FAH2
J701 8245311006 CONN, RCA, 6P,YKC21-3154
J706 8245311001 CONN, RCA, 1P,YKB11-0273
S601 8253467000 SW, SS010-P022MAM-PA9
S602 8253467000 SW, SS010-P022MAM-PA9
W601 8277473001 CORD, SCN-SCN, 8P x 200
W602 8277473001 CORD, SCN-SCN, 8P x 200
W603 8277473002 CORD, SCN-SCN,10P x 200
8207012800 HEATSINK, PC1115-25

PH-50
9
PH-50 PCB PATTERN DRAWING

10 PH-50
4. CIRCUIT & BLOCK DIAGRAMS
+B1
R117
10
R118
5.6
C107
0.1u
2
3
1
J101
HTJ064
PHONES OUT 1
R119
3.3k
R159
3.3k
C104
16V/330u
C109
0.047u
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U102
386B
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U152
386B
R116
10k
C103
0.001u
C153
0.001u
C105
10v/47u
R156
10k
R154
3.3k
R115
3.3k
R114
3.3k
C101 10p
+B2
-B2
R112 100k
R113
3.3k
C102
0.1u
1
5
2
4
3
U101A
4570A
R110
39k
R111
39k
+B2
R752
27k
R753
27k
R751
220k
9
8 6
7
U605B
4570A
D751
1SS133 D754
1SS133
D753
1SS133
R754
100k
R755
4.7k
R759
4.7k
D752
L-934ID-5V
D802
L-934ID-5V
+B2
+B2
-B2 -B2
C751
0.1u
R756
4.7k
R757
100
R758
0
C753
0.1u
1
5
2 4
3
U605A
4570A
C608
10p
C611 10p
R624 10k
C605
100p
R618 10k
+B2
R619
8.2k R621
8.2k
2
1
3
S601A
SSSF 2-2
-10dBV
R623
10k
R610
100k
C601
25V/22u
R611
10k
R612
10k
3
J603B
RCA 6P
UNBAL.IN L
-10dBV
2
3
1
J601
HTJ064
R613
10k
R614
10k
R616
100k
C602
25V/22u
R626
100k
3
J604B
RCA 4P
BAL.IN L
+4dBu/-10dBV
1
2
3
J602
CANNON
AUX IN L
-10dBV
C614
25V/22u R627
39k
C603
25V/22u
R615
100k C604
100p
C606
0.1u
C607
25V/22u
C615 10p
-B2
-B2
+B2
R628 39k
R629
3.3k
R620
8.2k R622
39k
+4dBu
C662
0.1u
R617
10k
1
5
2
4
3
U601A
4570A
1
5
2
4
3
U701A
4570A
C610
25V/22u
+B2
-B2
-B2
+B2
C656
0.1u
R631
10k
R630
10k
R632 39k
1
5
2
4
3
U651A
4570A 1
5
2
4
3
U602A
4570A
R625
1K R633
100
C617
25V/22u
C612
0.1u
R150
39k
R151
39k
2
1
5 34
67
R602
5kAA
C151 10p
R212 100k
C201 10p
+B2
+B2 2
1
5
3
4
6
7
R101
5kAA
R152 100k
R153
3.3k
98
6
7
U101B
4570A
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U202
386B
R216
10k
C203
0.001u
C155
10v/47u
C205
10v/47u
R215
3.3k
R214
3.3k
R155
3.3k
+B1
R217
10
R158
5.6
R218
5.6
C108
0.1u
R157
10
2
3
1
J201
HTJ064
PHONES OUT 2
R219
3.3k
C154
16V/330u
C204
16V/330u
C159
0.047u
R258
5.6
R257
10
R259
3.3k
C254
16V/330u
C209
0.047u
C259
0.047u
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U252
386B
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U302
386B
R316
10k
C253
0.001u
C255
10v/47u
C303
0.001u
R256
10k
R314
3.3k
R255
3.3k
R254
3.3k
C251 10p
-B2
+B2 2
1
5
3
4
6
7
R201
5kAA
R252 100k
R213
3.3k
C202
0.1u
98
6
7
U201B
4570A
1
5
2
4
3
U201A
4570A
R210
39k
R211
39k
R251
39k
R250
39k
R673
100
2
1
3
4
5
6
7
8
W601
2
1
3
4
5
6
7
8
62903579
C660
25V/22u +B2
5
46
S602B
SSSF 2-2 2
13
S602A
SSSF 2-2
+B2
C658
10p
2
1
5
34
67
R601
5kAA
R670
10k
R672 39k
C661
10p
R664
10k
98
6
7
U602B
4570A
98
6
7
U651B
4570A R665
1K
C657
25V/22u
C655
100p
C654
100p
R658 10k
+B2
R663
10k
R659
8.2k R661
8.2k
R660
8.2k R662
39k
5 4
6
S601B
SSSF 2-2
-10dBV
+4dBu
R657
10k
98
6
7
U601B
4570A
R650
100k
R651
10k
R652
10k
R653
10k
R654
10k
R656
100k
C653
25V/22u
C652
25V/22u
6
J604D
RCA 4P
2
3
1
J651
HTJ064
1
2
3
J652
CANNON
-10dBV
BAL.IN L
+4dBu/-10dBV
C651
25V/22u
R655
100k
R701
100k
C701
25V/22u
C664
25V/22u
7
8
J701
RCA 6P
R667
39k
AUX IN R
-10dBV
-10dBV
CHANNEL IN 1
R666
100k
2
3
1
J605
RCA JACK SW
C665 10p
+B2
R668 39k
R669
3.3k
98
6
7
U701B
4570A R671
10k
C667
25V/22u
R310
39k
R311
39k
R351
39k
C301 10p
C351 10p
2
1
3
4
5
6
7
8
9
10
W603
62903580
2
1
3
4
5
6
7
8
9
10
+B2
-B2
2
1
5
3
4
6
7
R301
5kAA
R312 100k
R352 100k
R253
3.3k
R313
3.3k
C302
0.1u
1
5
2
4
3
U301A
4570A
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U352
386B
R356
10k
C353
0.001u
C305
10v/47u
C355
10v/47u
R355
3.3k
R354
3.3k
R315
3.3k
+B1
R317
10
R318
5.6
R358
5.6
R357
10
C307
0.1u
2
3
1
J301
HTJ064
PHONES OUT 3
R319
3.3k
R359
3.3k
C304
16V/330u
C354
16V/330u
C309
0.047u
C359
0.047u
+B1
C409
0.047
R417
10
R418
5.6
C308
0.1u
2
3
1
J401
HTJ064
PHONES OUT 4
R419
3.3k
R459
3.3k
C404
16V/330u
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U402
386B
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U452
386B
R456
10k
C403
0.001u
C453
0.001u
C405
10v/47u
R416
10k
R454
3.3k
R415
3.3K
R414
3.3k
C401 10p
+B2
-B2
+B2
R412 100k
R353
3.3k
R413
3.3k
C402
0.1u
1
5
2
4
3
U401A
4570A
98
6
7
U301B
4570A
R350
39k
R411
39k
R410
39k
2
1
3
4
5
6
7
8
W602
2
1
3
4
5
6
7
8
62903579
R702
100k
R703
100k
R704
100k
R705
100k
C702
25V/22u
C703
25V/22u
C704
25V/22u
C705
25V/22u
2
1
J603
RCA 4P
5
4
J603
RCA 4P
1
2
J701
RCA 6P
4
5
J701
RCA 6P
-10dBV
-10dBV
-10dBV
-10dBV
CHANNEL IN 2
CHANNEL IN 3
CHANNEL IN 4
CHANNEL IN 5
6
J701
RCA 6P
9
J701
RCA 6P
-10dBV
-10dBV
CASCADE OUT L
CASCADE OUT R
D601
L-934ID-5V
R638
3.3k
R639
3.3k
R636
100k
R635
100k
Q603
B1237
Q601
D1858
Q602
D1858
R640
2.2k
R641
2.2k
C622
50V/2.2u
C804
0.1u
+B1
IN
3 OUT 1
G
2
U801
78M12AHF
Q801
C4549
R805
100 C806
25V/22u
+B2
R451
39k
R450
39k
C451 10p
C501 10p
+B2
2
1
5
3
4
6
7
R401
5kAA
R452 100k
R512 100k
98
6
7
U401B
4570A
R453
3.3k
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U502
386B
R516
10k
C503
0.001u
C455
10v/47u
C505
10v/47u
R515
3.3k
R514
3.3k
R455
3.3k
+B1
R517
10
R458
5.6
R518
5.6
C752
0.1u
R457
10
2
3
1
J501
HTJ064
PHONES OUT 5
R519
3.3k
C454
16V/330u
C504
16V/330u
C459
0.047u
C509
0.047u
R558
5.6
R557
10
R559
3.3k
C554
16V/330u
C559
0.047u
G
1 -
2 +
3 E
4 O5
B6
P7
G2 8
U552
386B
R556
10k
C553
0.001u
C555
10v/47u
R555
3.3k
R554
3.3k
C551 10p
+B2
-B2
+B2
2
1
5
3
4
6
7
R501
5kAA
R552 100k
R513
3.3k
R553
3.3k
C502
0.1u
98
6
7
U501B
4570A
1
5
2
4
3
U501A
4570A
R510
39k
R511
39k
R551
39k
R550
39k
C807
25V/22u
-B2
C805
0.1u
C803
25V/1000u
IN
2 OUT 1
G
3
U802
79M12AHF
C802
25V/3300u C801
25V/1000u
C810
25V/1000u
4
2
1
3D801
RB151
R803
100
C621
50V/2.2u
D603
1SS133
D602
1SS133
R634
27k R637
10k
C620
50V/2.2u BP
Q604
D1858
R801
F2.2
R802
F2.2
C808
0.0047
C809
0.0047
1
2
3
CN802
XH3P
R804
100
ToTransformer

PH-50
11
BLOCK DIAGRAM

12
PH-50
FOSTEX CORPORATION 3-2-35 Musashino, Akishima, Tokyo, Japan 196-0021
FOSTEX CORPORATION OF AMERICA 15431 Blackburn Ave., Norwalk, CA 90650, U.S.A. © PRINTED IN JAPAN JUNE 1998 8288774000