R
LTO
User's Manual
MISTRAL 900/1500
STEREO POWER AMPLIFIER
www.altoproaudio.com
Version 1.0 OCT. 2007
English
IMPORTANT SAFETY INSTRUCTION
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
TO REDUCE THE RISK OF ELECTRIC SHOCK
PLEASE DO NOT REMOVE THE COVER OR
THE BACK PANEL OF THIS EQUIPMENT.
THERE ARE NO PARTS NEEDED BY USER
INSIDE THE EQUIPMENT. FOR SERVICE,
PLEASE CONTACT QUALIFIED SERVICE
CENTERS.
WARNING
To reduce the risk of electric shock
and fire, do not expose this equipment
to moisture or rain.
Dispose of this product should
not be placed in municipal waste
and should be separate collection.
11. Move this Equipment only with a cart,
stand, tripod, or bracket,
This symbol, wherever used, alerts you to the
specified by the
presence of un-insulated and dangerous voltages
manufacturer, or
within the product enclosure. These are voltages that
sold with the
may be sufficient to constitute the risk of electric
Equipment. When
shock or death.
a cart is used, use
This symbol, wherever used, alerts you to
caution when
important operating and maintenance instructions.
moving the cart /
Please read.
equipment
Protective Ground Terminal
combination to
AC mains (Alternating Current)
avoid possible
Hazardous Live Terminal
injury from tip-over.
ON: Denotes the product is turned on.
12. Permanent hearing loss may be caused by
OFF: Denotes the product is turned off.
exposure to \ extremely high noise levels.
CAUTION
The US. Government's Occupational Safety
Describes precautions that should be observed to
and Health Administration (OSHA) has
prevent damage to the product.
specified the permissible exposure to noise
1. Read this Manual carefully before operation.
level.
2. Keep this Manual in a safe place.
These are shown in the following chart:
3. Be aware of all warnings reported
with this symbol.
HOURS X DAY SPL EXAMPLE
4. Keep this Equipment away from water and
90 Small gig
8
moisture.
92 train
6
5. Clean it only with dry cloth. Do not use
95 Subway train
4
solvent or other chemicals.
97 High level desktop monitors
3
6. Do not damp or cover any cooling opening.
100 Classic music concert
2
Install the equipment only in accordance with
102
1,5
the Manufacturer's instructions.
105
1
7. Power Cords are designed for your safety. Do
110
0,5
not remove Ground connections! If the plug
0,25 or less 115 Rock concert
does not fit your AC outlet, seek advice from
a qualified electrician. Protect the power
According to OSHA, an exposure to high SPL in
cord and plug from any physical stress to
excess of these limits may result in the loss of
avoid risk of electric shock. Do not place
heat. To avoid the potential damage of heat, it is
heavy objects on the power cord. This could
cause electric shock or fire.
recommended that Personnel exposed to
equipment capable of generating high SPL use
8. Unplug this equipment when unused for long
hearing protection while such equipment is
periods of time or during a storm.
under operation.
9. Refer all service to qualified service personnel
The apparatus shall be connected to a mains
only. Do not perform any servicing other than
those instructions contained within the
socket outlet with a protective earthing
User's Manual.
connection.
10. To prevent fire and damage to the product,
use only the recommended fuse type as
indicated in this manual. Do not short-circuit
the fuse holder. Before replacing the fuse,
make sure that the product is OFF and
disconnected from the AC outlet.
The mains plug or an appliance coupler is used
as the disconnect device, the disconnect device
shall remain readily operable.
IN THIS MANUAL:
1. INTRODUCTION.........................................................................1
2. FEATURES................................................................................1
3. CONTROL ELEMENTS................................................................2
4. APPLICATION............................................................................5
5. TECHNICAL SPECIFICATIONS.....................................................13
6. WARRANTY.............................................................................14
1. INTRODUCTION
Thank you for purchasing the MISTRAL 900/1500.
They are the line of high power, low profile, professional Power Amplifiers with
advanced features and great reliability. They deliver tremendous power in only
two rack spaces, providing high level performance under the most demanding
conditions. An automatic speed fan matches cooling capacity with heat requirements.
The amplifiers contain two independent channels, with separate AC transformer
secondaries, power supplies and protection system. Each channel has independent
protective circuitry against open circuit, short circuit, mismatched loads and
over temperature and LED indicators for operating/protection, limit, power on
and clip. The power outputs employ standard power connectors and all the inputs
are electronically balanced.
Enjoy your MISTRAL900/1500 and make sure to read this Manual carefully before
operation.
2. FEATURES
Mountable in a 19" unit (2U), stereo high power amplifier
Fantastic audio quality even with extremely high volume levels
Solid and durable can be mounted into a cabinet
User-controllable clip limiter
2
300 Watt EIAJ on 4 ohms for MISTRAL 900
2
500 Watt EIAJ on 4 ohms for MISTRAL 1500
Stereo (dual-channel) or bridge mono operating modes
Balanced XLR inputs/parallel outputs to ensure noiseless long wiring
Binding post and Neutrik Speak-on connectors for output
Single channel, bridge and bi-amp output wiring possibility
Front panel LED indicators for operating/protection, limit, power on and clip
Accurate gain control
Independent DC and thermal overload protection on each channel automatically
protects amplifier and speakers
Over-heat protection for each channel
Manufactured under QS9000, VDA 6.1 certified management system
1
SP
OT
L
3. CONTROL ELEMENTS
IG
HT
2
3
1500
ON
CH1
CH2
CLIP
LIMIT
OPERATING/
PROTECTION
POWER ON
OFF
POWER
1
R
Stereo Power Amplifier
4
5
LTO
6
1 POWER SWITCH
It switches the amplifier ON and OFF.
2 CLIP LED
When the signal distortion reaches or surpasses 0.5% , the LED lights up. This
means the output level of signal source is too high and it is time to reduce the
input level until the LED turns off.
3 OUTPUT LIMITER LED
When the unit limits the output signal, the LED lights up.
4 OPERATION AND PROTECTION LED
When there presets signal, the yellow LED lights up. When at protection status,
the LED turns off.
5 POWER LED
This LED lights up when the unit is powered on.
6 LEVEL CONTROL (For CH 1 & CH 2)
Adjust the output signal level to avoid signal distortion.
2
SP
OT
L
3. CONTROL ELEMENTS
IG
HT
Rear panel
7
9
14 11
12
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
2
1
3
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
1
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
BRIDGE
MONO
CH2
1+
1POS NEG
CH2
SERIAL
CH2
PARALLEL
OUTPUT
13
OUTPUT2
10
8
7 COOLING FAN
This fan secures enough cooling for your amplifier. The fan speed is electronically
regulated depending on the temperature of the power devices.
8 IEC SOCKET FOR AC POWER CABLE
Connect the supplied main cord. Do not insert the power cord into the MISTRAL
900/1500 amplifiers and into the AC Outlet until voltage has been correctly set.
9 CIRCUIT BREAKER (Manual reset button)
This is an electronic fuse for protecting the unit from possible damage. When
the unit is overloaded or the temperature inside the unit is too high, this push
type button will spring out and disconnect the power supply. Push the Breaker
down again to restore normal working conditions.
10 OUTPUT CONNECTOR
These connectors have two kinds: Binding post and Neutrik connector. You can
choose proper connectors according to practical need. For your safety, please
be careful when do connecting work.
11 LIMITER SWITCH
Set the switch at "ON" position, when the output level is above maximum, the
clip begins, thus keeping consistent output level for protecting apparatus. If
the switch is set at "OFF" position, this clip function doesn't work.
12 BALANCED INPUT CONNECTOR
These connectors connect the input signal of CH 1 and CH 2 separately.
13 BALANCED OUTPUT CONNECTOR
These two output connectors are parallelled inside with input connectors. It enables
the unit work under parallelled mode. Please also refer to wiring diagram for
parallelled mode.
3
SP
OT
L
3. CONTROL ELEMENTS
IG
HT
14 MODE SELECTOR
The MISTRAL 900/1500 power amplifiers present two operating modes:
- Stereo Mode
In this mode, CH 1 and CH 2 operate independently (as a normal stereo amplifier).
The CH 1 input signal will be output from the CH 1 output connector, and CH 2
input signal will be output from the CH 2 output connector.
- Bridge Mode
In this mode, CH 1 input signal will be output from the bridge-mono output connector.
On the other hand, the output level control of CH 2 should be turned to the minimum.
4
4. APPLICATION
The MISTRAL 900/1500 amplifiers provide two operating modes: stereo mode and
bridge mode, you can decide each specific operating mode according to your actual
application circumstance. Please see following diagram for connecting the power
amplifier into your audio system.
- Stereo Mode
In this mode, CH 1 and CH 2 operate independently (as a conventional stereo amplifier).
The CH 1 input signal will be output from the CH 1 output connectors, and the CH 2
input signal will be output from the CH 2 output connectors.
Input Connector
Balanced
+
GND
1
3
2
CH 1
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
CH 2
Stereo Mode
Release this button
PARALLEL
OUTPUT
OUTPUT2
CH 1
+
CH 2
5
4. APPLICATION
- Stereo Mode
Input Connector
Balanced
GND
1
3
2
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
CH 2
Stereo Mode
Release this button
PARALLEL
OUTPUT
OUTPUT2
CH 1
CH 1
+
CH 2
+
6
4. APPLICATION
- Stereo Mode
You can also operate the parallelled mode via outside wiring, so the signal input from
CH 1 or CH 2 will be output from both CH 1 and CH 2 simultaneously. The volume of
CH 1 or CH 2 can be controlled separately.
Input Connector
Balanced
+
GND
1
3
2
CH 1
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
PARALLEL
OUTPUT
OUTPUT2
CH 2
Stereo Mode
Release this button
CH 2
7
4. APPLICATION
- Stereo Mode
Input Connector
Balanced
GND
1
3
2
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
PARALLEL
OUTPUT
OUTPUT2
CH 2
CH 1
+
CH 2
+
Stereo Mode
Release this button
8
4. APPLICATION
- Stereo Mode
Input Connector
Balanced
+
GND
1
3
2
CH 1
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
Stereo Mode
Release this button
PARALLEL
OUTPUT
OUTPUT2
CH 1
CH 2
9
4. APPLICATION
- Stereo Mode
Input Connector
Balanced
GND
1
3
2
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
Stereo Mode
Release this button
PARALLEL
OUTPUT
OUTPUT2
CH 1
CH 1
+
CH 2
+
10
4. APPLICATION
- Bridge Mode
In this mode, the CH 1 input signal will be output from the bridge output connector.
On the other hand, the output level control of CH 2 should be turned down to smallest
(turn the volume control at counterclockwise). Only the volume control of CH 1 is used
to control the volume of the whole system.
Input Connector
Balanced
GND
1
3
2
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
PARALLEL
OUTPUT
OUTPUT2
CH 1
Bridge Mode
Press this button
CH 2
CH 1
11
4. APPLICATION
- Bridge Mode
Input Connector
Balanced
GND
1
3
2
INPUT
POWER OUTPUTS
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
NEW
2
TIDE
1
CH2
2+
2POS NEG
MODE
MODEL
NEW
TIDE
3
2
STEREO
BRIDGE
PARALLEL
OUTPUT
INPUT
CH1
TIP/PIN 2
RING/PIN 3
SLEEVE/PIN 1
1
Apparaten skall anslutas
till jordat uttag nar den
ansluts till ett natverk
CH1
1+
1POS NEG
1
3
3
2
2
1
3
LIMITER
OFF
ON
BRIDGE
1+
2+
POS NEG
CH1
BREAKER
OUTPUT1
CH2
1+
1POS NEG
BRIDGE
MONO
CH2
SERIAL
CH2
PARALLEL
OUTPUT
OUTPUT2
CH 1
CH 2
Bridge Mode
Press this button
CH 1
12
6. WARRANTY
1. WARRANTY REGISTRATION CARD
To obtain Warranty Service, the buyer should first fill out and return the enclosed
Warranty Registration Card within 10 days of the Purchase Date.
All the information presented in this Warranty Registration Card gives the
manufacturer a better understanding of the sales status, so as to provide a
more effective and efficient after-sales warranty service. Please fill out all the
information carefully and genuinely, miswriting or absence of this card will void
your warranty service.
2. RETURN NOTICE
2.1 In case of return for any warranty service, please make sure that the
product is well packed in its original shipping carton, and it can protect your
unit from any other extra damage.
2.2 Please provide a copy of your sales receipt or other proof of purchase with
the returned machine, and give detail information about your return address
and contact telephone number.
2.3 A brief description of the defect will be appreciated.
2.4 Please prepay all the costs involved in the return shipping, handling and
insurance.
3. TERMS AND CONDITIONS
3.1 LTO warrants that this product will be free from any defects in materials
and/or workmanship for a period of 1 year from the purchase date if you
have completed the Warranty Registration Card in time.
3.2 The warranty service is only available to the original consumer, who purchased
this product directly from the retail dealer, and it can not be transferred.
3.3 During the warranty service, LTO may repair or replace this product at its
own option at no charge to you for parts or for labor in accordance with the
right side of this limited warranty.
3.4 This warranty does not apply to the damages to this product that occurred
as the following conditions:
Instead of operating in accordance with the user's manual thoroughly, any abuse
or misuse of this product.
Normal tear and wear.
The product has been altered or modified in any way.
Damage which may have been caused either directly or indirectly by another
product / force / etc.
Abnormal service or repairing by anyone other than the qualified personnel or
technician.
And in such cases, all the expenses will be charged to the buyer.
3.5 In no event shall LTO be liable for any incidental or consequential damages.
Some states do not allow the exclusion or limitation of incidental or
consequential damages, so the above exclusion or limitation may not apply to
you.
3.6 This warranty gives you the specific rights, and these rights are compatible
with the state laws, you may also have other statutory rights that may vary
from state to state.
14
SEIKAKU TECHNICAL GROUP LIMITED
NO. 1, Lane 17, Sec. 2, Han Shi West Road, Taichung 40151, Taiwan
http://www.altoproaudio.com Tel: 886-4-22313737
email: alto@altoproaudio.com Fax: 886-4-22346757
All rights reserved to ALTO. All features and content might be changed
without prior notice. Any photocopy, translation, or reproduction of part of this
manual without written permission is forbidden. Copyright c 2007 Seikaku Group