Halcro DM8 Manuale utente
Preamplifier with remote control
Owner’s Manual
www.halcro.com
dm8
1
Contents
Introduction................................................2
Important Safety Information...................3
Electrical safety............................................. 3
Protection from fluids .................................. 3
Service warnings .......................................... 3
Product Design..........................................4
Electronic design.......................................... 4
Industrial design............................................ 6
Mechanical design ........................................7
Installation...................................................8
Unpacking ..................................................... 8
Storing packaging ........................................ 8
Positioning..................................................... 8
Controls and Connections.......................9
Front panel .................................................... 9
Rear panel ....................................................12
Remote control ...........................................14
dm8 outputs ................................................15
Connecting signal sources ........................ 15
Connecting home theater processor......15
Connecting to a power amplifier ..............16
Connect the mains supply cable.............. 17
Bridging......................................................... 17
Break-in period............................................ 17
Programmable input selections................ 17
Operation..................................................18
Start up .........................................................18
Source setup ...............................................18
De-allocating program buttons ................18
Display...........................................................18
Volume..........................................................19
Electronic Protection and Reliability..... 22
Components............................................... 22
Mains transient overload protection ....... 22
dm8 Specifications................................. 23
Care and Maintenance.......................... 26
Cleaning....................................................... 26
Troubleshooting...................................... 27
Service and Warranty Information ....... 28
Overview ..................................................... 28
Product warranty ....................................... 28
Exclusions to the warranty ....................... 28
Transferability.............................................. 29
Warranty verification .................................. 29
Warranty registration ................................. 29
If service is required ................................... 29
Transportation of products....................... 30
Freight damage claims.............................. 30
If you have moved ..................................... 30
Thank you for choosing Halcro!............... 30
2
Introduction
Congratulations on purchasing the Halcro
dm8 preamplifier.
It has taken two years and the generous
contributions of leading reviewers, distributors
and dealers from around the world to design,
then create, the Halcro preamplifiers. We are
confident that this combination of expertise,
along with the know-how of the high-end
audio industry’s leading Research and
Development team will ensure the success of
the Halcro preamplifiers.
The brief given to our R&D team, headed by
Bruce Candy, was to produce two models of
preamplifier to satisfy the needs of every
audio connoisseur:
•lowest distortion specifications of any
preamplifier in the world
•physical dimensions to suit a standard
domestic equipment rack, while retaining
the stunning Halcro industrial design
signature
•tractable controls
•superior reliability
•innovation in design
The Halcro dm8 preamplifiers will add no
colorations to the music. When used in
conjunction with Halcro power amplifiers, all
you will hear is the original recording
reproduced the way the artist intended it to
sound. No transistor or valve-added sounds
are present, just a level of musical purity that
was thought impossible until now.
Please enjoy the Halcro audio experience.
Halcro has enjoyed creating perfect audio
reproduction for the world's music
connoisseurs.
If you desire to contact Halcro to give us
feedback on your purchase or for general
enquiries, please feel free to:
or phone: + 61 8 8238 0807
or fax: + 61 8 8238 0852
3
Important Safety Information
Electrical safety
Only suitable approved MAINS cords, as per
European individual country requirements in
the CE Low Voltage Directive Scheme, shall
be used with this unit.
Do not use extension cords: To avoid safety
hazards, use only the power cord supplied
with your unit.
No naked flame sources, such as lighted
candles, should be placed on the unit.
The dm8 is designed to operate on any mains
supply in the range of 90 to 240 V, 50 to
60 Hz, without any internal or external
switches.
Protection from fluids
This device is designed for indoor use only
and is not protected against liquids. It must not
be exposed to dripping or splashing, and no
objects filled with liquids, such as vases,
should be placed on it.
IMPORTANT - This product must
always be connected to an
earthed voltage supply.
Service warnings
This product contains no user serviceable
parts.
WARNING: do not use any
cables longer than three meters.
All compartments are sealed at the factory. If
the seals are broken, the warranty will be void
and all service costs will be charged to the
owner.
DANGER: Contains no user
serviceable parts. Do not
attempt to open any of the
amplifier compartments, as
this may expose you to
dangerous voltages and will
void the warranty.
W
ARNING: Weighs 2
3
kg (50 lb)
per unit. Shipping weight is 36 kg
(79 lb). Never lift the amplifier by
yoursel .f
Requires F2AL 250 V fuse for continued
protection against the risk of fire. Never
bypass or use any other type of fuse. The fuse
is located on the rear panel in the main switch.
4
Product Design
Electronic design
by Bruce Candy
In keeping with my philosophy of design, my
basic aim was to produce a preamplifier with
which I, personally, am quite satisfied. I
sincerely hope that others will share my
satisfaction with these products.
As I saw it, the major issues were:
•zero compromise on Transparency
•flexibility
•ease of use
•progressive design concepts
In order to meet this challenge, the resulting
circuits have particular characteristics:
First, all circuits in the preamplifier have
distortion so low that it is immeasurable,
whether THD, IM and so on.
Second, all circuits in the preamplifier exhibit
exceptionally low noise (see specifications).
Third, there is no compromise whatever with
the choice of components (Vishay resistors,
FKP1 capacitors and so on).
Fourth, the circuits are highly immune to
electromagnetic interference. Some inputs
and outputs include both first order filters and
common mode chokes.
Fifth, the power supply and microprocessor
circuits are designed for minimal
electromagnetic emissions (extensive 2nd to
6th order filters).
Sixth, the power supply switching frequency
was chosen to be much higher than the audio
band (>200 kHz).
Seventh, the power supply rails are
exceptionally well regulated, double regulation
in fact (switch-mode and linear servo loops).
Eighth, components and design are selected
for high reliability.
The volume control is implemented so as to
include two identical stages in series. This
minimizes output noise.
The dm8 and dm10 preamplifiers feature
balanced, unbalanced, current mode and
bridged current mode outputs. The latter
consists of a non-inverted and inverted
current output. There is also an unbalanced
output for tape and headphones.
5
Audible relay noise
The dm8 and dm10 use mechanical relays in
all switching including the volume control
because they exhibit the following ideal
characteristics:
•zero ON resistance
•infinite OFF impedance
•very low OFF capacitance
•zero distortion
In contrast, the now universally popular solid-
state relays/switches exhibit none of these
ideal properties and detract from
performance. Hence, sonically, Halcro feels
that it is worth the side effect of mechanical
clicking sounds when parameters are
changed.
Microprocessor control
The excellent audio electronics are
complemented and controlled by a number of
highly integrated micro-controllers located
close to the electronics they serve. Being as
near as possible to the controlled electronics
allows short control paths and virtually
eliminates internal connectors, thereby greatly
increasing system reliability.
Each amplifier channel has its own micro-
controller; the front panel display and user
interface has another. A fourth micro-
controller, located on the rear connector
panel, co-ordinates the activity of the others.
The four micro-controllers are linked via only
four interconnections each.
A unique programming feature of the
microprocessor has been developed which
allows the user to dedicate a particular pair of
input sockets to a specific input device. This
feature provides the user with great flexibility
for connecting input devices to the
preamplifier.
On the rear panel there are one pair of current
inputs, three pairs of balanced inputs and
three pairs of unbalanced inputs.
6
Industrial design
Product form
The aim when designing the dm8 and dm10
was to create a preamplifier that was
unmistakably part of the Halcro product family,
but at the same time a component that would
complement any high-end audio system.
The preamplifier had to sit comfortably within a
contemporary domestic environment, retain
the visual signature of the Halcro family of
products, which differentiates them from
other high-end audio products, and have an
appearance that reflected the high level of
technical innovation. As with other Halcro
products, softer forms and textures are used,
all fasteners are concealed and the heat sinks
are integrated into the external form to
maintain simple, clean lines.
While the unique pillar forms of the power
amplifiers have been carried through to the
preamplifier, proportions have been reworked
to allow this component to be either
freestanding or housed within a standard 19”
shelving system.
Control interface
Knobs and buttons
The volume and input selector knobs use a
unique magnetic incremental indexing
mechanism developed to provide a very
subtle and reliable indexing action. The knobs
and buttons are finished in the same soft
textural finish as the pillars.
Control interface
Knobs and buttons
The volume and input selector knobs use a
unique magnetic incremental indexing
mechanism developed to provide a very
subtle and reliable indexing action. The knobs
and buttons are finished in the same soft
textural finish as the pillars.
7
t
Display
A high-resolution display was chosen in order
to provide clean simple graphics without the
rough edges associated with displays of
lesser quality. The graphic layout of the display
has been optimized to give prominence to the
functions that are viewed most often. These
include volume levels, balance and input
selection. Functions that are accessed less
often are displayed in smaller type along the
bottom of the screen. These include
stereo/mono and in or out-of-phase. The
volume levels for each channel are displayed
side-by-side so that when the levels are not
equalized the user will easily notice it.
Remote con rol
When designing the Halcro Remote Control,
we aimed to reflect the quality and forms of
the Halcro preamplifiers. Machined from a
solid aluminum extrusion, the remote rests
comfortably in the right hand with its minimalist
array of buttons falling within the natural
sweep of the thumb. Simple and logical to
operate, every effort has been made to keep
this product free of unnecessary complexity.
Mechanical design
The Halcro dm8 and dm10 can boast their
spectacularly low noise and distortion
specifications while their cases contain
inherently noisy digital circuitry, including a
switch-mode power supply, partly due to the
mechanical design of their circuit boards and
the boxes that contain them. Supports of
folded aluminum serve not only as bases to
which the electronics are anchored, but also
to shield different sections of the circuitry from
one another.
Each of the audio, panel and display, and
power supply sections is contained within its
own internal aluminum enclosure. Cables
connecting the separate sections are few and
short, minimizing both radiation and reception
of unwanted signals.
8
Installation
Ensure you have read the Important Safety
Information on page 3, before installing your
Halcro preamplifier.
If you require assistance in the unpacking and
installation of your Halcro preamplifier, please
contact your dealer.
Unpacking
oUnscrew the four knurled knobs at the
base of the container, and then remove
the upper part of the container by lifting
directly upwards, until it clears the top of
the preamplifier.
oRemove the plastic wrapping and foam
pieces, then lift the preamplifier from the
base of the container and remove the
plastic covering from the unit.
Please save all packaging material for
later use.
oRemove the centerpiece of foam in base
of transit case, to locate the remote
control and power cable.
oWearing the white cotton gloves
provided (to prevent marking the
preamplifier while moving it in to position),
move the unit to its final location (see
Positioning).
Storing packaging
The packaging is custom designed to prevent
damage from occurring during transport.
Store the packaging in a dry location.
Positioning
The Halcro dm8 preamplifier can be placed
anywhere indoors. There is no need to leave
room around the unit to allow for ventilation as
the dm8 does not generate significant
amounts of heat.
To ensure ultimate performance and to avoid
potential safety hazards, place the unit on a
firm, level surface. When placing the unit on a
shelf, be certain that the shelf and mounting
hardware can support the weight of the
product.
Do not connect to mains power
until all the connections are
made and checked.
9
Controls and Connections
Front panel
Figure 1
1. LCD information display
2. Balance control left
3. Standby/On button
4. Mute button
5. Balance control right
6. Input select control
7. Volume control
8. Phase button
9. Remote sensor window
Altri manuali per DM8
1
Indice
Altri manuali Halcro Amplificatore
Halcro
Halcro MC30 Manuale utente
Halcro
Halcro MC20 Guida rapida
Halcro
Halcro MC70 Manuale utente
Halcro
Halcro Eclipse mono Manuale utente
Halcro
Halcro DM10 Manuale utente
Halcro
Halcro MC70 Guida rapida
Halcro
Halcro MC70 Manuale utente
Halcro
Halcro MC30 Guida rapida
Halcro
Halcro SSP100 Manuale utente
Halcro
Halcro DM8 Manuale utente
