Yamaha P1150 User manual

Scan Revision
“POWER AMPLIFIERS
P1150/P1250/
P2150/P2250
SERVICE MANUAL
•P2250
CONTENTS
IMPORTANT NOTICE 1
SPECIFICATIONS 1~4
PERFORMANCE GRAPHS 5/6
PANEL LAYOUT 7/8
DISASSEMBLY PROCEDURES 9/10
CHECK AND ADJUSTMENT 10
BLOCK DIAGRAM 11
DIMENSIONS 11
CIRCUIT BOARDS 12-16
EXPLODED VIEW 17
PARTS LIST 18-24
SCHEMATIC DIAGRAM 25
|006650|~©YAMAHA
NIPPON GAKKI CO., LTD. HAMAMATSU, JAPAN
1.8r)K-845 n®Printed in Japan '8.5.4

PI 150/Pl 250/P21 50/P2250
IMPORTANT NOTICE
This manual has been provided for the use of authorized Yamaha Retailers and their service personnel.
It has been assumed that basic service procedures inherent to the industry, and more specifically Yamaha
Products, are already known and understood by the users, and have therefore not been restated.
WARNING: Failure to follow appropriate service and safety procedures when servicing this product
may result in personal injury, destruction of expensive components and failure of the
product to perform as specified. For these reasons, we advise all Yamaha product owners
that all service required should be performed by an authorized Yamaha Retailer or the
appointed service representative.
IMPORTANT: The presentation or sale of this manual to any individual or firm does not constitute
authorization, certification, recognition of any applicable technical capabilities, or
establish aprinciple-agent relationship of any form.
The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The
research, engineering, and service departments of Yamaha are continually striving to improve Yamaha
products. Modifications are, therefore, inevitable and changes in specification arc subject to change without
notice or obligation to retrofit. Should anv discrepancy appear to exist, please contact the distributor's
Service Division.
WARNING: Static discharges can destroy expensive components. Discharge any static electricity your
body may have accumulated by grounding yourself to the ground buss in the unit (heavy-
gauge black wires connect to this buss).
IMPORTANT: Turn the unit OFF during disassembly and parts replacement. Recheck^work before
you apply power to the unit.
SPECIFICATIONS
P1 150
Output Power Specs meet
FTC preconditioning criteria
OUTPUT SPECIFICATIONS
20Hz -20kHz IMHz -20kHz

PI 150/Pl 250/P21 50/P2250
P1250
Output Power Specs meet
FTC preconditioning criteria
OUTPUT SPECIFICATIONS
8ohms 14ohms 1
20Hz -20kHz 1kHz 20Hz -20kHz 1kHz
Continuous sine wave output power
at less than 0.05% THD 170W 185 W250 W265 W
Total Harmonic Distortion (THD) <0.007%
@85 W<0.003%
(3185 W<0.01%
@125 W<0.005%
@125 W
Intermodulation Distortion (IHD)
60 Hz &7kHz 4:1<0.005% (S) 85 W<0.01% @125 W
Power Bandwidth (@ THD *^0.1%) 10 Hz to 100 kHz @85 W10 Hz to 100 kHz @125 W
Frequency Response (1 watt output) +0.-1 dB, 10 Hz to 50 kHz
Damping Factor >110(31 1kHz >55@ 1kHz
Slew Rate ±50 volts/microsecond full swing
Signal-to-Noise (Input shorted) >110dB, -6dB/octave LPF (s> 12.47 kHz
>115dB, IHF-A network
Residual Noise
(Input ATT @> minimum) <-80 dBm, -6dB/octave LPF (§1 12,47 kHz
<—90dBm, IHF-A network
Input Impedance >15 kohms, balanced or unbalanced (ATT @max)
Sensitivity +4 dBm (1.23 Vrms) for nominal output (4 ohm load)
Voltage Gain 28.3 dB
Indicators
Signal: Green LED turns on when signal present at output
is at or above 2volts RMS (20 Hz -20 kHz),
Clipping: Red LED turns on when THD >1%.
Protection: Red LED turns on when protection or muting is on.
Pilot: Red LED turns on when power is on.
Protection Circuits
Muting: Output muted 6seconds (±2 sec.) after power is on,
DC sense: Output shut off if ±2V DC sensed at output.
Thermal: Output shut off if heat sink temp. >85 degrees C.
Current
Limiter: Output reduced if load <2 ohms.
Fan Circuit Fan is normally at low speed; when heat sink reaches 60 degrees
Centigrade, fan goes to high speed; then resets to low at 45°C.
Controls
Front: 32 step Input Attenuator; 0to —20 dB in 1dB steps,
-20 to -30 dB in 2dB steps, then -33, -37, -42, -50, -60
dB, and infinite attenuation.
Push On/Push Off POWER switch.
Power Requirements 105- 130 volts, 50 or 60 Hz, AC, 400 W(450 VA)
Weight 33 lbs (15 kg)
Dimensions Width: 18-7/8 inches (480 mm)
Height: 5-1/4 inches (132 mm)
Overall Depth: 16-3/4 inches (423 mm)
Depth Behind Front Panel: 15-1/8 inches (384 mm)
Accessory Rubber cap to discourage unauthorized or accidental changes in
setting of input attenuator (included).

PI 150/Pl 250/P21 50/P2250
P2150
STEREO OPERATION (Power output specified
per channel, with both channels driven) BR IDGED MONO OPERATION
Output Power Specs meet 8ohms 4ohms 16 ohms 8ohms
20Hz -
20kHz 1kHz 20Hz - 20kHz 20Hz -
20kHz 1kHz 20Hz-
20kHz
Continuous sine wave output power
at less than 0.05% THO 100 w105 W150 W165
W
220 W250 W300 W330 W
Total Harmonic Distortion (THD) <0.007%
@>55W <0.003% @55W <0.01% <0,005% @75 W@75 W<0.007% @110 W<0.003%
@now <0.01% <0.005% @150W @150W
Channel Separation (@ 3 dB below
nominal power output, ATT @ max,
input shorted) >70dB >90 dB
Intermodulation Distortion (IHD)
60 Hz &7kHz 4:1<0.005% (S) 55 W<0.01% @75 W<0.01% @110 W<0.01% @> 150 W
Power Bandwidth (@ THD <0.1%) 10Hz to 50 kHz<s>55 W10 Hz to 50 kHz (5) 75 W10 Hz to 50 Hz @110
W
10 Hz to 50 kHz (3 150 W
Frequency Response (1 watt output) +0, -IdB, 10Hz to 50kHz
Damping Factor >110C 1kHz >55@ 1kHz
Slew Rate ±50 volts/n
full swing licrosecond ±90 volts/microsecond
full swing
Signal-to-Noise (Input shorted) >110 dB, -6 dB/octave LPF (3 12.47 kHz
^115 dB, IHF-A network >106d
>110d B, -6 dB/oct
B, IHF-A net
ave LPF @12,47 kHz
Residual Noise
(Input ATT @ minimum) <-80 dB
^-90 dB T), -6 dB/octave LPF @12.47 kHz
Ti, IHF-A network
Input Impedance >15kohnIS, balanced ounbalanced (ATT @max)
Sensitivity +4 dBm (1 23 Vrms) fo nominal output (4 ohm load)
Voltage Gain 26.0 dB
Indicators
Signal:
Clipping:
Protection
Pilot:
Green LED
(20 Hz -20
Red LED tu
Red LED tu
Red LED tu
urmon whensgnal presen
rnson when THD >1% (x
rns on when protection or
rns on when power is on.
tat output is
2).
volts RMS
Protection Circuits
Muting:
DC sense:
Thermal:
Current L
Output shui
Output shut
miter: Outpu
sd 6seconds (± 2sec.) afte
off if ±2V DC sensed at o
off if heat sink temp. >85
reduced if load <2 ohms
power Is on.
degrees C.
Fan Circuit Fan is normally at low s
then resets to low at 45 peed; when heat sink reaches 60 degrees
C.
Centigrade, fa goes to high speed;
Controls
Front: 2x32 step Input Attenuators; 0to —20 dB
-33, —37, —42, -50, -60 dB, and infinite attenuat
Push On/Push Off POWER switch.
Rear: MONO/STEREO MODE switch.
n1dB steps. -20 to -30 dB in 2dB steps, then
Power Requirements 105- 130 volts, 50 or OHz, AC, 500 W(600 VA
Weight 37.4 lbs (1 7kg)
Dimensions Width:
Height:
Overall De
Depth Behpth: nd Front Par
18-7/8 inches (480 mn
5-1/4 inches (132 mn
16-3/4 inches (423 mn
el: 15-1/8 inches (384 mn
1)
1)
Accessories Rubber ca
(included)
as of discourage unauthorized or acciden al changes in setting of inp jt attenuators

PI 150/Pl 250/P21 50/P2250
P2250

PI 150/Pl 250/P21 50/P2250
PERFORMANCE GRAPHS
THD vs OUTPUT POWER CHARACTERISTICS
THD vs OUTPUT POWER CHARACTERISTICS
<Model: P2150> Load Impedance; 8n
Mode; STEREO
Both Channels Driven
THD vs OUTPUT POWER CHARACTERISTICS
<Model: P2150> Load Impedance; 8f2
Mode: MONO (BTL)
THD vs OUTPUT POWER CHARACTERISTICS
<Model; ’P2250> Load Impedance: 4n
Mode: STEREO
Both Channels Driven
5
THD vs FREOUENCY CHARACTERISTICS
<Model; P2150> Load Impedance: 4f2
Mode: STEREO
Both Channels Driven
Output Power: 75W constant
THD vs FREQUENCY CHARACTERISTICS
<^odel: P2150> Load Impedance: 8n
Mode: MONO (BTL)
Output Power: 150W constant
THD vs FREQUENCY CHARACTERISTICS
<Modet; P22S0> Load Impedance: 4Ii
Mode: STEREO
Both Channels Driven
Output Power: 125W constant

PI 150/Pl 250/P21 50/P2250
THD vs OUTPUT POWER CHARACTERISTICS
<Model: P2250> Load Impedance: 8n
Mode: STEREO
Both Channels Driven
.nO VS OUTPUT POWER CHARACTERISTICS
<Model; P2250> Load Impedance: 8n
Mode: MONO (BTL)
THD vs FREQUENCY CHARACTERISTICS
<Model: P2250> Load Impedance: 812
Mode: STEREO
Both Channels Driven
Output Power: 85W constant
<]Model; P2250> Load Impedance: 8n
MODE: MONO (BTL)
Output Power: 250W
DAMPING FACTOR CHARACTERISTICS
<Model: P2250> Load Impedance; 812 FREQUENCY RESPONSE CHARACTERISTICS
<^odel: all models> Load Impedance: 812
Input Attenuators: Max

P2150

P1 150/PI 250/P21 50/P2250
DISASSEMBLY PROCEDURES
•Disconnect each connector as necessary for the part •Electric charge may be accumulated at the electro-
removal. lyfic capacitor of the power supply. Discharge it by
shorting across the capacitor terminals with aresistor
of 8J2, 100W or so.
FLOW CHART
I®Top cover removaT] [0Filter removal ~\
OUTPUT circuit board check r
Idling current adjustment |
DC offset check 1
Front panel aaembly removal
|[d) PA unit removal |
PAA (PAB) circuit board removal |
Cooling Fan removal ||dRear panel assembly removal
I®OUTPUT circuit board removal|
Shield bracket removal
IINPUT circuit board removal
®TOP COVER REMOVAL/GRILLE REMOVAL ®FRONT PANEL ASSEMBLY REMOVAL
9

PI 150/Pl 250/P21 50/P2250
(D PA UNIT REMOVAL ®REAR PANEL ASSEMBLY REMOVAL/
OUTPUT CIRCUIT BOARD REMOVAL
CHECK AND ADJUSTMENT
BEFORE ADJUSTING
Be sure to wait for about 5minutes after turning the
power switch on, in order for the main amp's operation
to become stable.
1. Idling current adjustment 2. DC offset check
Adjust VR201 (and/or VR301) so that the voltage Check that the voltage across the SPEAKER terminals
across the test points TP203 and TP204 on the PAA cir- $and ©is 0±lOmV in ano signal condition,
cuit board (and/or TP303 and TP304 on the PAB circuit
board) is 12mV ±0.5mV in ano signal condition.
FRONT
io

PI 150/Pl 250/P21 50/P2250
CIRCUIT BOARDS (Parts side)
•INPUT CIRCUIT BOARD
12

PI 150/Pl 250/P21 50/P2250

PI 150/Pl 250/P21 50/P2250
16

PI 150/Pl 250/P21 50/P2250
PARTS LIST
Ref.
No Part No. Description *S, «Remarks Common
Model Markets
1AA 83 29 00 Chassis ^P11 50/PI 250
„AA 83 28 90 „II P2150/P2250 1
2CB 80 65 90 Foot m1
3Ei 34 01 06 Bind Head Tapping Screw 4x10 Bl /iA
4EV 41 30 46 Toothed Lock Washer A4S Bl «a&^1
5NB 83 18 70 Power Transformer «»h7>XP1 150 J
„NB 83 19 10 nII II U,C
„NB 83 19 50 nII II G
„NB 83 18 50 „II PI 250 J
„NB 83 18 90 „II II u,c
NB 83 19 30 „II II G
„NB 83 18 60 II P2150 J
„NB 83 19 00 I, II II U,C
„NB 83 19 40 „II II G
„NB 83 18 90 nII P2250 J
1, NB 83 18 80 „II II U,C
nNB 83 19 20 „II II G
6ED 35 01 06 Bind Head Screw 5X10 Bl '< '( >y
7EV 20 30 56 Flat Washer 5S Bl ¥*A
8EV 30 35 06 Spring Washer 5S Bl ^
9CB 03 54 00 Holder, Circuit Board D-85 V-h4-. tu -
10 AA 83 31 20 Rear Panel >J 7iy tp PI 150m/ J
„AA 83 31 30 1, HII U,C
„AA 83 31 40 „/; II G
„AA 83 30 00 n// P1250ML J
/, AA 83 30 10 »nII U,C
HAA 83 30 20 1, II II G
„AA 83 30 60 »II P2150Mi J
„AA 83 30 70 HII II u,c
AA 83 30 80 „II II G
AA 83 29 40 „II P2250M'i J
„AA 83 29 50 nII II u,c
„AA 83 29 60 nII II G
1
1
CB 80 86 50 Power Cord Holder a_K-fP 1
12 Ei 34 01 26 Bind Head Tapping Screw 4x12 Bl 1
13 LB 20 29 40 Fuse Holder 15A 250V ta-X4-. ;p -1J.U.C
,, LB 20 05 90 n6.3A 250V II 1G
14 KB 00 04 00 Fuse 5A 250V ti-XP1 150 J
// KB 00 14 20 «5A 125V nII u,c
„KB 00 07 60 „T315A 250V II II G
/, KB 00 13 00 // 7A 250V II P1250 J
«KB 00 15 20 n7A 125V II II u,c
KB 00 07 90 ,1 T4.0A 250V II II G
„KB 00 14 90 1, 10A 250V II P2150 J
nKB 00 13 90 n10A 250V II II U,C
nKB 00 07 70 // T6.3A 250V II II G
nKB 00 12 70 1, 15A 125V II P2250 1J
nKB 00 13 80 II 15A 250V II II 1U,C
nKB 00 07 90 II T4.0A 250V II II 1G
15 AA 83 32 50 Fuse Cover tIL -X*-P2250M;.C 1J,C
16 Ei 33 00 86 Bind Head Tapping Screw 3x8 Bl II 1J,C
17 EV 41 30 36 Toothed Lock Washer A3S Bl «ft a A II 1J,C
18 LA 00 07 60 Lug Terminal 2P 75’- a^ « 1J
*New Parts (*r«Sa)

PI 150/Pl 250/P21 50/P2250
1jga Part No. Descriptior S&«Remarks Model Markets 7>y
1El Ei 33 00 86 Bind Head Tapping Screw 3x8 Bl
1RSI EV 41 30 36 Toothed Lock Washer A3S Bl «ft *A1
1mMG 00 06 10 Power Cord 15A 125V 2.1m «*3-K1J
1WM MG 00 05 30 „10A 125V 2.2m II 1U,C
1WM MG 00 11 30 „6A 250V 3.5m 1, 1G
1WSM CB 80 68 50 Cord Stopper 6N3-4 3-KXh-y -1J.U.C
nCB 03 28 40 „5N-4 II 1G
*23 NA 81 39 60 INPUT Circuit Board =91980 INPUT >-FP1150M; J
*„NA 81 39 70 1, „II II u,c
*„NA 81 39 80 ,1 „II II G
*„NA 81 40 80 „nII P1250h^ J
*—NA 81 40 90 „ „ II II u.c
iINA 81 41 00 „„II II G
nNA 81 40 20 „ „ II P2150f\; J
INA 81 40 30 „„II II U.C
NA 81 40 40 „II II II G
BNA 81 41 40 n1, II P2250h4 J
BNA 81 41 50 n1, II II U.C
NA 81 41 60 1, II II II G
BEV 41 00 98 Toothed Lock Washer A9S Bl «#®*KfllSCC
BLX 20 00 1
0
Plain Washer 9S Cr 1# Si tp «A
LX 20 00 60 Hexagonal Nut 9S Ni «A«-y F)1
BCB 06 88 80 Plastic Rivet y^X-y- y^r'I-^ yFG
ElEi 34 00 86 Bind Head Tapping Screw 4x8 Bl
BLB 10 11 60 Receptacle AMP
E9LB 101 1 80 Housing II
Ei 34 00 86 Bind Head Tapping Screw 4x8 Bl U,C
cTI EV 41 30 46 Toothed Lock Washer A4S Bl «ft ^u,c
BNA 81 42 40 OUTPUT Circuit Board =92350 OUTPUT -FPI 150/PI 250 FU J,G
BNA 81 46 00 HII II II U
BNA 81 45 70 II II II II C
»NA 81 45 30 II II II P2150MX J,G
HBNA 81 45 90 II II II II U
BNA 81 45 60 II II II II C
BNA 81 42 60 II =91990 II P2250Ka J,G
*BNA 81 45 80 II II II II U
BNA 81 45 50 II II II II C
CA 80 91 60 Insulating Washer tt» n-y >y-1C
35 CB 81 00 90 Insulating Nut « « tf yFPZ2SCM,' J
36 Ei 33 00 66 Bind Head Tapping Screw 3x6 Bl i
37 LB 20 15 40 Phone Jack ->> -V -y ^M2 C
38 EV 41 00 98 Toothed Lock Washer A9S Bl «ft *&1C
* 39 BA 81 01 40 Front Panel 7n>Fy< ^/k :P1 150
*// BA 81 01 00 II II P1250Hx
// BA 81 01 20 II II P2150M..i
nBA 81 00 80 II II P2250
40 CB 83 57 00 Switch Escutcheon X< yf^IX* y>3> 1
ss BCB 83 56 90 Knob Escutcheon •yviIX*y->a>
BBA 80 19 50 Handle 7;y X>F' 7k
* 43 AA 83 29 20 Sub Panel -if 7y< +7k 1
44 ED 35 01 26 Bind Head Screw 5X12 Bl y< >F' ']' +-7 1
*45 JC 00 1 1 50 Cooling Fan it m77>1B
46 CB 83 58 70 Duct yyF1HB
*New Parts (Sf«»a)
19