Alto HPA6 Owners Manual

R

LTO

OWNER'S MANUAL

HPA6

6-CHANNEL HEADPHONE AMPLIFIER

www.altoproaudio.com

Version 2.4 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.

1.

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

2.

Be aware of all warnings reported

3.

with this symbol.

4.

Keep this Equipment away from water and
moisture.

5.

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

6.

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

7.

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

8.

periods of time or during a storm.

Refer all service to qualified service personnel

9.

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 SPL EXAMPLE

Small gig

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.

90

train

92

Subway train

95

High level desktop monitors

97

Classic music concert

100
102
105
110

Rock concert

115

IN THIS MANUAL:

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

2. FEATURES.....................................................................................1

3. CONTROL ELEMENTS....................................................................2

4. APPLICATIONS...............................................................................5

5. INSTALLATION AND CONNECTION..................................................7

6. TECHNICAL SPECIFACATION...........................................................9

7. WARRANTY...................................................................................10

1. INTRODUCTION

Thank you for your purchasing of the HPA6, 6-channel headphone amplifier. It is just
one of the many Alto products that a talented, multinational Team of Audio Engineers
and Musicians have developed with their great passion for music. Your HPA6 has
been designed for applications such as recording, broadcast and Live events. It is a
very flexible tool allowing personal headphone mix for up to six musicians.
Enjoy your HPA6 and read this Manual carefully before operation!

2. FEATURES

Mountable in a 19" Rack Unit
6 individual headphone channels
Input gain control, and individual output gain control
Up to 3 headphone outputs per channel for a total of 18 headphones
Direct In and Headphone Output on the front panel for easy operation, when
mounted in a rack
Input and Output Level Led Meter
BalanceControltomixuptheMainInandtheAuxInsignal
Main Outputs for linking additional HPA6 headphone amplifiers
High-end quality even at high volume levels
Exceptionally rugged construction ensures long life and durability
Universal and professional headphone amplification system for studio and
stage application
Manufactured under QS9000 certified quality system

LTO

NPUTLEVEL dBu)

4 1 12 0 1 8

2

DRECT IN

0
NPUTGA N

MAINSECTION

3

24 0 12

MUTELR

3

4

5

6

4

CLP

5

1

0

MANIN

AUX

BALANCED

OUTPUTGA N

AUX N

HEADPHONEOUT

MONO

STEREO

CHANNEL1

24 0 12

MUTELR

3

2

4

CLP

5

1

6

0

MANN

AUX

BALANCED

OUTPUTGAIN

AUXIN

HEADPHONEOUT

MONO

STEREO

CHANNEL2

4 0 2

MU ELR

3

2

4

CLIP

5

0

MAINN

AUX

BALANCED

OU PUT GA N

AUX N

HEADPHONEOUT

MONO

S EREO

CHANNEL3

4 0 12

MUTELR

3

OUTPUTLEVEL dBu)OUTPUTLEVEL dBuOUTPUT LEVEL(dBu)OUTPUTLEVEL dBu)OUTPUTLEVEL dBu

MAI IN

BALANCED

CHANNEL4

24 0 12

5

1

0

AUX

OUTPUTGA N

AUX N

HEADPHONEOUT

CLP

MONO

STEREO

MUTELR

3

OUTPUTLEVEL(dBu)

4

CLP

5

1

6

0

MANN

AUX

BALANCED

OUTPUTGAIN

AUXIN

HEADPHONEOUT

MONO

STEREO

CHANNEL5

4 0 2

MUTELR

3

2

4

CLIP

MANN

BALANCED

MONO

STEREO

CHANNEL6

HPA6

5

0

AUX

OUT UT GA N

AUXIN

HEADPHONEOUT

6-CHANNEL
HEADPHONE

ON

AMPLIFIER

OFF

POWER

1

SPOTLIGHT

3. CONTROL ELEMENTS

11

3

5

5

9

10

1

AUX

OUTPUT GAIN

HEADPHONE OUT

3

2

4

5

6

0

8

LTO

INPUT LEVEL(dBu)

24 18 12 60 6 12 18

2

R

DIRECT IN

1

0

INPUT GAIN

MAIN SECTION

1 2

3

4

6

OUTPUT LEVEL(dBu)

24 0 12

MUTELR

5

7

CLIP

MAININ

MONO

STEREO

CHANNEL 1

6 4

BALANCED

AUX IN

MAIN SECTION:

1 DIRECT IN

You can use this socket to feed and additional stereo signal into your HPA6. This
socket is in "priority". It means that when you insert the jack, the signal fed into
the MAIN input on the rear panel will be disconnected.

2 INPUT GAIN

This knob controls the level of the signal applied to the MAIN or DIRECT IN inputs.

3INPUTLEVEL

This Led Meter informs you about the level of the input signal. The range goes
from 24 dBu to +18 dBu. For the best quality of input signal the operating
leds should be those from +6 to +18 dBu. The CLIP led should light up only
occasionally. If CLIP led is always on, you must reduce the input level through the
input gain control. If only -18 and -12 dBu leds are operating, you will experience
a bad S/N ratio and increase the input level.

CHANNEL SECTION

There are 6 identical channels on your HPA6 with identical functions and
performance.

4AUXIN

This stereo input is useful when you want to feed an additional signal with the signals
applied to MAIN or DIRECT IN inputs. If you have a stereo signal depress the MONO
switch. If you have a mono signal, press the MONO switch if you want such signal
to appear on both ears.

5 L&R MUTE SWITCHES

Through these switches you can mute the respective input signals one at a time
or both at the same time.

2