HEED OBELISK separates PRE and PX User manual

Users Manual
Thank you for choosing our products!
With the development of the OBELISK separates, our aim was to take our highly praised
and award-winning Obelisk Si integrated amplifier to the next level of performance, in terms
of both functionality and sound. Using separate components for the various amplifier stages
gives more flexibility of use and achieves more transparency, information retrieval and
dynamic capability. We sincerely hope that you will agree, and that your Obelisk separates
will provide you with many years of impeccable, trouble-free operation.
Happy listening!
These components are designed to offer the finest performance available by avoiding
compromise, wherever possible. This detailed guide contains advice specifically related
to using this amplifier combination, as well as more general warnings about the use of
domestic audio components.
OBELISK
separates
PRE and PX
SPECIFICATIONS
Input (1) impedance: 75 Ohm
Input (2-6) impedance: 10 kOhm
Input (2-6) sensitivity (at 775 mVRMS out): 220 mVRMS
Input (2) sensitivity / impedance with MM phono module 5 mV / 47 kOhm
Output impedance (Pre Out, Tape Out): 35 Ohm
Maximum output level (at THD = 1%): 7.5 VRMS
Gain: 10 dB
Headroom: 20 dB
Signal-to-noise ratio (A-weighted): 98 dB
Total harmonic distortion (at 775 mVRMS out), unweighted): <0,005 %
Frequency response (+0, -1 dB, unity gain): 1 Hz - 105 kHz
Frequency response (+0, -3dB, unity gain): 1 Hz - 220 kHz
Power consumption: <10 W
Power consumption (standby): 4 W (+1 W per module)
Weight (Obelisk PRE): 4.2 kg
(Obelisk PX): 5 kg
If within three years of the purchase date your Heed OBELISK PRE or PX prove to be defective
for any reason other than accident, misuse, neglect, unauthorised modification or fair wear and
tear, Heed Audio Ltd. will, at its discretion, replace the faulty parts without charge for labour. This
factory warranty is valid only for units sold into countries with no appointed Heed distributor.
Service enquiries in countries with appointed distributor should be addressed first to the
supplying dealer and/or Heed distributor. Warranties granted in these countries are entirely
at the discretion of distributor.
FACTORYCONTACT
DISTRIBUTOR CONTACT
WARRANTY
HEED Audio Kft. (Ltd) Tel/Fax: [phone]
Reviczky Gyula u. 9-11eMail: [email protected]
H-1181 Budapest
Hungary Web: www.heedaudio.com
Heed OBELISK PRE - Users Manual 1.1 (2010)

precautions
Instructions — All safety and operating instructions should be read and adhered to exactly as written here or as
depicted on the unit. Please retain for future reference.
Water and Moisture — The unit should not be used near water — that is, near a bathtub, washbowl, kitchen sink,
laundry tub,
in a wet basement, or swimming pool, etc.
Heat
—The unit should be situated away from heat sources such as radiators, stoves, etc..
Power Sources —The unit should be connected to a power supply only of the type described in the operating instructions
or as marked on the unit.
Power-Cord Protection — Power-supply cords should be routed so that they are not likely to be walked on or pinched
by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point
where they exit from the unit.
Lightning — For added protection during a lightning storm, or when left unattended and unused for long periods of time,
unplug the unit from the wall outlet. This will prevent damage to the product due to lightning and power-line surges.
Object and Liquid Entry
— Care should be taken so that objects do not fall into and liquids are not spilled into the inside
of the unit. For this reason,no objects filled with liquid, such as vases or drinking glasses should be placed on the equipment.
Damage Requiring Service — The unit should be serviced by qualified service personnel when:
— The power-supply cord or the plug has been damaged;
—
Objects have fallen, or liquid has been spilled into the unit; or the unit has been exposed to rain respectively;
— The unit does not appear to operate normally or exhibits a change in performance;
— The unit has been dropped, or the cabinet damaged.
The Obelisk PRE preamplifier, as well as its optional PX auxiliary power supply do not have
any user serviceable parts. It is essential that repairs and updates are only carried out by our
authorised trade partners —distributors and dealers —, or at the factory by Heed Audio
itself. Many components are custom made, tested or matched and appropriate replacements
are often unobtainable from other sources.
Therefore, users should not attempt to service the units beyond those means described
in the operating instructions, or under any circumstances allow anyone to modify them.
Unauthorised repairs or modifications will invalidate the guarantee of the units.
Grounding or Polarization —Precautions should be taken so that the grounding or polarization is not defeated.
Radio interference — All Heed components are designed to provide reasonable protection against harmful interference
in a domestic installation. However, there is no guarantee that interference will not occur in a particular installation. If your
Obelisk does cause harmful interference to radio or television reception, which can be determined by turning off and on,
you are encouraged to try to correct the interference by one or more of the following measures:
— Reorient or relocate the receiving antenna;
— the separation between amplifier and receiver (radio tuner, television set, etc.);
— Connect the equipment into a power outlet on a circuit different from that to which the receiver is connected;
— your Heed dealer or an experienced radio/TV technician for help.
Maintenance / Cleaning — It is recommended to dust the equipment from time to time with a soft dry cloth.
Do not use cleaning solvents or abrasives for cleaning!
Always switch off and unplug the unit from the power supply when cleaning!
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1 Volume Knob 3 Position and on/off indicator LEDs
2 Input Selector Switch 4 Infrared sensor
7 Auxiliary Power Supply connector 19 No. 4. Line level input right channel
8 Pre-out 2, left channel connector 20 No. 3. Line level input left channel
5 Power on/off switch 17 No. 5. Line level input right channel
6 Mains connector and fuse socket assy 18 No. 4. Line level input left channel
9 Pre-out 2, right channel connector 21 No. 3. Line level input right channel
10 Pre-out 1, left channel connector 22 No. 2. Line level input left channel
11 Pre-out 1, right channel connector 23 No. 2. Line level input right channel
12 Tape Out, left channel connector 24 Earthing ( for tonarm cables only )
13 Tape Out, right channel connector 25 TOSLINK digital input (optical fiber)
14 No. 6. Line level input left channel 26 S/PDIF digital input (co-axial)
15 No. 6. Line level input right channel 27 Push-button switch (TOSLINK<>S/PDIF)
16 No. 5. Line level input left channel
front panel
rear panel

Installation
We believe that a Heed Audio component should, optimally, be installed by an approved Heed dealer. Nevertheless, the
procedure is straight-forward enough to enable you to install your new Obelisk PRE, and its PX power supply, if applicable,
yourself by following the instructions presented here.
Should any problems be experienced which are not covered here, contact your local dealer. If you are unable to do so,
or problems persist, however, do not hesitate to contact our distributor/trade partner in your country (see our website
< www.heedaudio.com > — “Worldwide distributors” —for details), or us directly at Heed Audio .… we're here for you!
When opening the box and unpacking the unit, you will find following items
supplied:
— (1) Heed Obelisk PRE line-level preamplifier
—
(1) OBELISK remote control handset
— (1) 6-pole 'shorting' power supply plug
— (1) IEC-norm mains power cord
— (1) Users Manual
Before placing the unit in its chosen location, insert the 'shorting' power supply plug into
the PSU socket (7) —see rear panel. Alternatively, you can use the Obelisk PX auxiliary
power supply via this socket (see below “Upgrade Options”). If the plug is not inserted in the
socket, the preamplifier is completely muted because the circuit is disconnected from the
onboard power supply, enabling the connection of the Obelisk PX.
In common with all high-quality audiophile equipment, the Obelisk PRE performs optimally when positioned on its own individual
mounting surface, ideally a light rigid structure. There are many purpose-built stands readily available from all better dealers.
Avoid placing the unit on soft surfaces, for example, carpets or soft fabrics. Keep it away from strong magnetic fields.
Before performing any connections or disconnections, ensure that the unit’s power on/off
switch (5) is in "off" position.
Always check that the voltage and frequency of the mains supply corresponds to the
specifications, as labelled on the unit!
Insert the power cord's IEC-type plug into the power inlet connector (6) of the Obelisk.
Connect the power cord's mains plug to your power outlet.
The Obelisk PRE has one dedicated digital (co-axial / optical fiber), and five pairs of high quality RCA (cinch) input connections.
Input 1 (25,26) is a true digital connection accepting digital output signals from various digital devices such as CD-transports,
CD- or DVD-players via their digital outputs, as well as computer music servers and DAB-tuners. This input works via either
optical fiber TOSLINK (25) or co-axial S/DIF (26) connection, if the input is equipped with the optional Heed Audio Dactil DAC
module. Input 2 (22,23) can also be used as digital input (co-axial only), if equipped with its own DAC module. (Either the Left
or Right RCA jack may be used to accept a suitable digital source, but only one (1) of them may be used as such, with the other
remaining unconnected.) This input, as opposed to the digital-only Input 1, can be used, alternatively, as a standard line level
input or even as a phono input for connecting a turntable, if equipped with the optional Heed Audio Vinyl-1 MM phono module.
Inputs numbers 3 to 6 (14-21) are standard line level inputs. See the specifications section for the sensitivity data of the inputs.
unpacking
placement
connection to mains supply
input connections
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'shorting' power supply plug
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PRE OUT: The Obelisk PRE has two pre-out (RCA) connections (8,9 and 10,11). Here you can connect your power amplifier,
ideally the Heed Audio Obelisk PS stereo amplifier or a pair of Obelisk PM mono power amplifiers to drive your loudspeakers.
When connecting the Obelisk PRE to power amplifier(s) ensure that the “L” (left) and “R”
(right) channels are connected correctly.
As the Obelisk PRE features two pre-out connections, it is also possible to use two Obelisk PS, or four Obelisk PM units
for bi-amplification. This configuration benefits most loudspeakers. Provided your speakers have a terminal with separate
connectors for low/mid and high frequencies, remove the “bridge” between them (which must be used if driving them with a
single amp set) and connect the low/mid way to “Pre Out 1” with one set of interconnect cables and the high way to “Pre Out”
2
(or the other way round) with another set of interconnects. If you have problems, contact your Heed dealer and seek advice.
TAPE OUT: Using this output, you can connect an analogue or digital recorder to your Obelisk PRE. If you also want to
listen to the recorder, you have to connect the output of the recorder to one of the line-level inputs (14-21) of the Obelisk PRE.
Alternatively, it is possible to drive a headphone amplifier via the “Tape Out”, ideally our Heed Audio CanAmp.
It is strongly recommended to use decent interconnect cables between your Obelisk PRE and
your other hi-fi components connected to it — better quality interconnects can usually
enhance
the performance of your system. One of the best choices is our HEED ConCord cable. Your
HEED dealer will certainly help you to choose the right connections for your particular set-up.
Operation
Once the Obelisk PRE is connected to the mains supply, as well as to source component(s)
and power amplifier(s), remove the protective film from the front panel(s) — the same
applies to the PX power supply, if applicable. You can detach it by grabbing the film at any
of the corners and peeling it off.
When all installation steps have been correctly completed, your amplification is ready for action!
Turn the Volume Knob (1) counter-clockwise to the minimum setting.
Switch on your desired source components.
Switch on amplifier units with power on/off switch (5,29) and allow some time for warming up.
If your unit was transported or stored in a cold environment, allow it to
warm up to room temperature before switching on!
Select the component that you'd like to listen to with the Input Selector Switch (2).
Begin playing the source component.
Adjust the volume level with the Volume Knob (1) or with the Remote Control Handset >>>
to your preferred setting: up with , down with . You can also mute the amp by pressing .
Sit back and enjoy!
output connections
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This step concerns only the appearance of the units, it has no electrical or mechanical influence on their
functioning.
Note:
Although the components can be used within seconds of switching on, as with all audio equipment the best
sound quality will be reached after a warm-up period: a minimum of 30 minutes, preferably a couple of hours.
As the units draw very little power, unless it is out of use for a long period, we recommend keeping them
switched on permanently for optimum performance. However, all units should be switched off if left unattended
for extended periods, or in the event of a thunderstorm.
Note:

The Obelisk PX is a fully regulated auxiliary power supply which fundamentally improves the sonic performance of the
Obelisk PRE preamplifier.
In this enhanced two-box configuration, the Obelisk PX power supply will take over the support of all audio and operational
stages of the Obelisk PRE from its on-board power supply. To avoid unwanted electrical and magnetic interference, the
Obelisk PRE must be switched off when supported by the Obelisk PX.
Before performing any connections or disconnections ensure that the power on/off
switch (5) of the unit is in the "off" position.
Never attempt to connect any other type of power supply to this connection as it may
cause your equipment to fail!
The Obelisk PRE is a highly versatile preamplifier and
can be used with the vast majority of power amplifiers.
We suggest, however, that you combine it with one
(or more) of our Obelisk power amplifiers, which is a
perfect match both technically and sonically.
Follow these steps when connecting pre- and power
amplifier(s):
Before performing any connections or disconnections ensure that the power on/off
switches (5) of the units are in the "off" position.
Connect the pre- and power amplifiers by plugging a pair of interconnecting RCA (cinch) cables into one of the pre-out
connectors (8,9 and 10,11) of the Obelisk PRE and to the input connectors of the Obelisk PS or PM at the other end.
Ensure that the “L” (left) and “R” (right) channels are connected correctly to preamplifier
and power amplifier(s).
Switch on the units with their power on/off switch — first PRE (or PX) and then power amplifier(s).
Obelisk PX auxiliary power supply (optional)
connecting the Obelisk PX to the Obelisk PRE
Obelisk PS stereo and PM mono power amplifiers
1. Connect one end of the supplied P.S. connector
to
the P.S.output socket of PX (31), and the other
end to the P.S. input socket of Obelisk PRE (7).
2. Connect the supplied power cord's IEC type plug
into the power inlet connector of the Obelisk PX
(30), and its mains plug into your power outlet.
3. Switch the PX power on/off switch (29) to "on".
Confirm blue LED power indicators are lit on both
PRE and PX units. Allow time for warm-up. Enjoy!
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Note: Obelisk PRE remains switched off.
For a detailed description, refer to the separate instruction manual supplied with the Obelisk PS or PM.
Upgrade Options
Upon installation of the Heed Audio Dactil DAC module for Input 1 and/or Input 2, your Obelisk PRE will be able to receive
the digital signal of CD-transports, CD- or DVD-players, music servers or any other source component with a digital output,
and convert it into a line-level analogue signal. If you don’t use Input 2 for vinyl reply, you can connect up to two digital source
components
and use them simultaneously, although you need a DAC module for each. Additionally, you can share Input 1
between two source components — one connected via S/PDIF and the other via TOSLINK — and use them by toggling (27).
Upon installation of the Heed Audio Vinyl-1 MM phono module, your Obelisk PRE will be able to amplify a signal directly
from the cartridge (moving-magnet) of your record player. Note: only Input 2 (22,23) can be used with the phono module.
If you use Input 2 for vinyl replay, you need to change the jumper settings (Line
— Phono) on the PCB inside the unit.
We strongly recommend that the installation of modules and changing of jumper settings be
carried out by your authorised Heed Audio dealer, so the description outlined below is for
reference purposes only!
D-to-A converter (DAC) and MM phono modules
Before installation of the module your equipment must be
switched off, and disconnected from the power supply.
All input/output cabling should be disconnected.
1. Remove the housing cover.
2. Set the correct position of the jumpers (30) with a pair of tweezers or even with
your fingertips: "Phono" for the Vinyl-1 phono or Dactil DAC module respectively,
“Line” for any line-level source component (slot remains vacant).
Input 1 accepts only the Dactil DAC module and therefore needs no jumpering.
3. Connect the module(s) to the main PCB by sliding it on the pin connectors of
the slot(s) — No. 28 for Input 1 and No. 29 for Input 2.
4. Reassemble the housing cover.
5. Re-connect all cables —see "installation”, page 4.
6. Connect your turntable to Input 2 (22,23) and its tonearm’s grounding cable, if
available, to the “earthing screw” (24). Pay attention to polarity (“+” to “+”, ”-” to “-”).
[OR] Connect your digital source (CD-transport, computer server, DAB-tuner, etc.)
via co-axial
interconnect cable to either the Left or Right RCA jack of Input 2 (22,23),
leaving the other jack unconnected.
If you have a DAC module connected to Input 1, you will probably use your primary
digital source with it (connected to No. 25 via TOSLINK, or No. 26 via S/PDIF).
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phono module Heed Audio Vinyl-1 MM DAC module Heed Audio Dactil
While Input 1 comes with both S/DIF (co-axial) and TOSLINK connections, Input 2 can be used as a co-axial
connection only.
Note: