Alto D3, D2, D1, D4 Owners Manual

LTO

OWNER'S MANUAL

D1/D2/D3/D4

PROFESSIONAL POWER AMPLIFIERS

www.altoproaudio.com

Version 1.3 SEPTEMBER 2007

English

IMPORTANT SAFETY INSTRUCTION

CAUTION

RISK OFELECTRIC SHOCK

DO NOTOPEN

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.

This symbol, wherever used, alerts you to the

presence of un insulated and dangerous voltages within the product enclosure. These are voltages that may be sufficient to constitute the risk of electric shock or death.

This symbol, wherever used, alerts you to important operating and maintenance instructions.

Please read.

Protective Ground Terminal AC mains (Alternating Current)

Hazardous Live Terminal ON: Denotes the product is turned on. OFF: Denotes the product is turned off.

CAUTION

Describes precautions that should be observed to prevent damage to the product.

Read this Manual carefully before operation. Keep this Manual in a safe place.

Be aware of all warnings reported

with this symbol.

Keep this Equipment away from water and moisture.

Clean it only with dry cloth. Do not use solvent or other chemicals.

Do not damp or cover any cooling opening. Install the equipment only in accordance with the Manufacturer's instructions.

Power Cords are designed for your safety. Do

not remove Ground connections! If the plug does not fit your AC outlet, seek advice from a qualified electrician. Protect the power cord and plug from any physical stress to avoid risk of electric shock. Do not place heavy objects on the power cord. This could cause electric shock or fire.

Unplug this equipment when unused for long

periods of time or during a storm.

Refer all service to qualified service personnel

only. Do not perform any servicing other than those instructions contained within the User's Manual.

To prevent fire and damage to the product,

10.

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.

WARNING

To reduce the risk of electric shock and fire, do not expose this equipment to moisture or rain.

Dispose of this product should notbeplacedinmunicipalwaste and should be separate collection.

MovethisEquipmentonlywithacart,

11.

stand, tripod, or bracket, specified by the manufacturer, or sold with the Equipment. When a cart is used, use caution when moving the cart / equipment combination to avoid possible injury from tip over.

12.

Permanent hearing loss may be caused by exposure to \ extremely high noise levels. The US. Government's Occupational Safety and Health Administration (OSHA) has specified the permissible exposure to noise level. These are shown in the following chart:

HOURS X DAY

8 6 4 3 2 1,5 1 0,5 0,25 or less

According to OSHA, an exposure to high SPL in excess of these limits may result in the loss of heat. To avoid the potential damage of heat, it is recommended that Personnel exposed to equipment capable of generating high SPL use hearing protection while such equipment is under operation.

The apparatus shall be connected to a mains socket outlet with a protective earthing connection.

The mains plug or an appliance coupler is used as the disconnect device, the disconnect device shall remain readily operable.

SPL

EXAMPLE

Small gig

train

Subway train

High level desktop monitors

Classic music concert

100 102 105 110 115

Rock concert

IN THIS MANUAL:

1. INTRODUCTION..............................................................................

2. FEATURES.....................................................................................

1 1

3. CONTROL ELEMENTS...................................................................5

4. OPERATION...................................................................................8

5. BLOCK DIAGRAM........................................................................11

6. TECHNICAL SPECIFICATION ........................................................12

7. WARRANTY.................................................................................13

1. INTRODUCTION

Thank you for expressing your confidence in LTO products by purchasing one or more of our D series power amplifiers. The D range includes D1, D2, D3 and D4. There are 2 channels for the D1/D3, and 4 channels for D2/D4. All models are rugged, 2 rack-unit amplifiers fan-cooled. They provide a lot of power and a high value performance. They are all designed for heavy-duty application and they all can drive 4 ohm loads for long periods without overheating. Therefore they are suited to drive subwoofers with a minimum load of 8 ohm when working in Bridge Mode.

Enjoy your D amplifier and make sure to read this manual carefully before operation!

2. FEATURES

Illuminated Power Switch Automatic Clip-limiter circuit Switchable low-frequency filter at 30 Hz Operating Mode is: Stereo, Parallel or Bridge Balanced Combo input connectors Output connectors are speak-on jacks and binding post terminals Low-noise, variable speed fan Front panel LED indicating Signal and Clipping and Protection Status Class D technology, switch power, light weight and high power Manufactured under TS16949, ISO14001 certified management system

SPOTLIGHT

SG CLIPPROT SG CL P PROT

CH1

SG CLIPPROT SG CL P PROT SIGCL P PROT IG CLIP PROT

CH1

SG CLP PROT SIG CL P PROT

CH1

28306

( B)

(dB)

CH2

28306

( B)

CH2

2806

(dB)

CH2

8306

(dB

dB)

CH3

CH4

28306

dB)

500W 2

8306

dB)

500W 4

750W 2

SIG CL P PROT SIG CLIP PROT SG CLIP PROT SG CL P PROT

28306

dB)

CH1

CH2

8306

dB)

( B)

CH3

CH4

2806

(dB)

750W 4

HOOK

STEREO MODE

In this mode 2 independent channels are sent to 2 separate speakers.

HOOK

PARALLEL MODE

One mono signal is input to CH A or CH B of the D series amplifier and then

output to 2 separate speakers. Each speaker volume can be set separately.

+ 11 hidden pages