POWER AMPLIFIER
XH150
Owner’s Manual
POWER
ON OFF
POWER SIGNAL CLIP SIGNALCLIPPROTECTION
CH A CH B
POWER AMPLIFIER XH SERIES
E
Introduction
Thank you for purchasing a Yamaha XH150 power amplifier.
The development of the XH150 was enriched by Yamaha’s wealth of experience in building
PA equipment and its tradition of precision circuit design technology. This amp is dedicated
to driving high-impedance speakers, and feature high power and superb quality together with
superior reliability and stability, guaranteeing the highest possible audio performance.
Main features of the XH150:
• The unit is equipped with two types of inputs (balanced XLR and barrier strip) and one
barrier strip output.
• The voltage line is switchable between 100 V and 70 V, and output is rated at 150 W.
The high-impedance design makes the unit most suitable for driving multiple speaker
systems simultaneously in a facility.
• Independent low-cut/high-cut filters are provided for channels A and B. These filters
allow you to change cut-off frequencies.
• A SIGNAL indicator and CLIP indicator is provided for each channel.
• The PROTECTION indicator shows the status of protective circuitry such as power-on/
off protection, output muting, and the DC detection circuit.
• Variable-speed low-noise fan(s) ensures high reliability even under demanding conditions.
In order to take full advantage of your XH150 and enjoy long and trouble-free operation,
please read this owner’s manual carefully before use.
WARNING: THIS APPARATUS MUST BE EARTHED
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN
ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH
BLUE : NEUTRAL
BROWN : LIVE
As the colours of the wires in the mains lead of this apparatus may
not correspond with the coloured markings identifying the terminals in
your plug, proceed as follows:
The wire which is coloured GREEN and YELLOW must be
connected to the terminal in the plug which is marked by the letter E
or by the safety earth symbol or coloured GREEN and YELLOW.
The wire which is coloured BLUE must be connected to the terminal
which is marked with the letter N or coloured BLACK.
The wire which is coloured BROWN must be connected to the
terminal which is marked with the letter L or coloured RED.
* This applies only to products distributed by YAMAHA KEMBLE
MUSIC (U.K.) LTD.
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Precautions
• Connect this unit’s power cord only to an AC outlet of
the type stated in this Owner’s Manual or as marked
on the unit. Failure to do so is a fire and electrical
shock hazard.
• Do not allow water to enter this unit or allow the unit
to become wet. Fire or electrical shock may result.
• Do not place heavy objects, including this unit, on top
of the power cord. A damaged power cord is a fire and
electrical shock hazard. In particular, be careful not to
place heavy objects on a power cord covered by a
carpet.
• Do not scratch, bend, twist, pull, or heat the power
cord. A damaged power cord is a fire and electrical
shock hazard.
• Do not remove the unit’s cover. You could receive an
electrical shock. If you think internal inspection,
maintenance, or repair is necessary, contact your
dealer.
• Do not modify the unit. Doing so is a fire and electrical shock hazard.
• If the power cord is damaged (i.e., cut or a bare wire is
exposed), ask your dealer for a replacement. Using the
unit with a damaged power cord is a fire and electrical
shock hazard.
• If you notice any abnormality, such as smoke, odor, or
noise, or if a foreign object or liquid gets inside the
unit, turn it off immediately. Remove the power cord
from the AC outlet. Consult your dealer for repair.
Using the unit in this condition is a fire and electrical
shock hazard.
• Should this unit be dropped or the cabinet be damaged,
turn the power switch off, remove the power plug from
the AC outlet, and contact your dealer. If you continue
using the unit without heeding this instruction, fire or
electrical shock may result.
• Hold the power cord plug when disconnecting it from
an AC outlet. Never pull the cord. A damaged power
cord is a potential fire and electrical shock hazard.
• Do not touch the power plug with wet hands. Doing so
is a potential electrical shock hazard.
• This unit has ventilation holes at the front, rear and
sides to prevent the internal temperature rising too
high. Do not block them. Blocked ventilation holes are
a fire hazard.
• Allow enough free space around the unit for normal
ventilation. This should be: 10 cm at the sides, 30 cm
behind, and 20 cm above.
These distances should also be adopted when rackmounting the unit. For normal ventilation during use,
remove the rear of the rack or open a ventilation hole.
If the airflow is not adequate, the unit will heat up
inside and may cause a fire.
• To mount several of these units in an EIA-compliant
rack, refer to the rack mounting instructions on page 9.
• Use only speaker cables when connecting speakers to
amplifier outputs. Using other types of cables is a fire
hazard.
• Do not use this amplifier for any purpose other than
driving loudspeakers.
• XLR-type connectors are wired as follows:
pin 1: ground, pin 2: hot (+), and pin 3: cold (–).
• Using a mobile telephone near this unit may induce
noise. If noise occurs, use the telephone away from the
unit.
• Clean the contacts of the phone plug before connecting
it to the SPEAKERS jack of this unit. Dirty contacts
may generate heat.
Contents
Controls and Functions ............................................................. 4
Front Panel........................................................................... 4
Rear Panel ........................................................................... 5
Connecting Speakers .......................................................... 6
Caution for Connection ............................................................. 8
Rack Mounting .......................................................................... 9
Mounting in an EIA standard rack ....................................... 9
General Specifications....................................................... 10
Specifications .......................................................................... 10
Block Diagram.................................................................... 11
Dimensions ........................................................................ 11
Troubleshooting ...................................................................... 12
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Controls and Functions
■ Front Panel
POWER
1
ON OFF
POWER
1 POWER switch and indicator
This is the main POWER switch. Press to power ON
the amplifier. Press again to power OFF. The POWER
indicator lights up when the amplifier is powered ON.
2 SIGNAL indicators
These green LED indicators light up when the
respective channel’s output signal exceeds 4 Vrms.
3 CLIP indicators
These red LED indicators light up when the respective
channel’s output signal distortion exceeds 1% (i.e.
clipping). Output signal clipping is usually due to
excessive input signal levels.
3
2
SIGNAL CLIP SIGNALCLIPPROTECTION
CH A CH B
4
4 PROTECTION indicators
These LED indicators light up to indicate that the
protection circuit is working. The speaker system is
disconnected from the amplifier outputs and no sound
is output from the speakers.
The protection circuit is activated in the following
situations:
• When the amplifier is powered on:
The protection circuit is activated for approximately 3
seconds when the amplifier is powered on. After 3
seconds, the protection system is deactivated automatically, and the amplifier is ready to use.
• If a DC voltage is present at the amplifier’s
outputs:
If the DC voltage problem is corrected, normal
amplifier operation resumes.
• If overheating occurs:
Turn off the power to the amplifier to cool down the
unit and consult the Precautions section of this manual
to improve the vent condition, if necessary. Turn the
power on to the amplifier after it cools down.
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