Table of content
Table of content
Welcome join KingRex usership
Performance & value
Engineering passion & design idea
Contents in this box
Safety instruction
Important safety instructions
Safety caution
Important warning
Operation environment presentation
Front panel details
Rear panel details
Connecting the cables and machine setting
Input setting
Output setting
How to operate
Specification of HEADQURATERS (HQ-1)
Feature of HEADQUARTERS (HQ-1)
Burin in
Trouble shooting
Service & Warranty
Welcome joins KingRex usership
After the first integrated amplifier T20 visit the Hi-Fi field globally, KingRex never stop designing and
creating “good” sounding products. Gladly, there are lots of audiophiles keep trying KingRex products, sharing
their feedbacks, and providing their opinions to help KingRex knowing the “good products” are worth to be
expected and it is able to survive in harsh tests.
KingRex is not very big company and it makes us have more elasticity to create more fitting personal
demand Hi-Fi gears as desktop integrated ampl-T20U or our new product- HEADQUARTERS headphone
It’s a coincident for KingRex to create the home use headphone amplifier. From the early beginning, the
headphone amplifier creation is all about the family member and closing friends’ request for good sounding
headphone amp. After the early stage product research and sample creation, we can’t stop thinking to create
one for our family and friends. So we trying to get it done and make it “great”. After the long time testing,
tuning, and practicing, our entire offer is trying to create one good headphone amplifier to fit the demand of
neutral and fidelity sound.
Before you start operating the HEADQUARTER (HQ-1), we hope you can spend some time to read this
user manual carefully. This user manual has fully instruction for how to install, operate, and preserve the
machines. It will help to extend the life circle of your HQ-1 and provide the best performance of your HQ-1.
Hope you will fully enjoy the music!!!
Sincerely yours,
All KingRex staffs
Performance & value
Move up the audio ladder. Connect to the headquarters.
Nothing can be more challenging than moving up the audio ladder in today’s economic climate. At KingRex,
we’re committed to putting money to where our ears are. (And so are you). After spending countless
months and sweat on developing and perfecting personal audio, we are proud to announce our inaugural
headphone amp, the Headquarters HQ-1. This exciting new establishment will fulfill our goal in the
following ways.
As the Headquarters that commands authority, the HQ-1 has adopted a two-chassis design with separate
power supply for sonic integrity. And it’s not the switch-mode power supply but audiophile grade linear
power with rock solid 45W toroidal transformer (18V / 2.5A) completed with 25,100uF total capacity of
reserve power and optimized regulatory circuit based on LMS 1585 constant voltage regulator.
As the Headquarters to co-ordinate and mobilize, the HQ-1 has an input/output impedance characteristic
that’s highly adaptable and will match nearly all headphones or earphones available in the market. Be it
audiophile grade, closed or open air type, in-ear monitors or portable audio ear buds, the HQ-1 proves to
be the perfect performance partner, yielding output power from 100mW at 300 ohm to 570mW at 30 ohm.
Thanks to the sophisticated Class A MOSFET circuitry, THD + N drop to a bottom-low 0.005% while
frequency response opens up wide at 20Hz to 80 kHz.
As the Headquarters to set high standard of performance, only top-notch audiophile grade components
are qualified to work here: Toshiba A970/C2240 for first stage amplification; Hitachi MOSFET 2SK214 for
output stage. Panasonic FM capacitors be choosen as main filter for transparent background and balanced
soundstage. WIMA input capacitors for enhanced acoustic density. Vishay output capacitors for more
neutral and delicate details. Gold-plated Neutrik 6.35mm headphone jack, gold-plated RCA terminals,
Neutrik XLR socket (DC power transmission), Furukawa PCOCC internal wiring and ALPS potentiometer
choose for sonic purity. What’s the result? The naturally expansive, warm sound and vivid dynamics
As the Headquarters to channel lines of communication, the HQ-1 in addition to headphone output is
equipped with RCA line output and can be used as a high-quality preamp, selectable through a push button
on the front panel.
As the Headquarters to bestow flagship image, the HQ-1 is furnished with two chassis designs: piano glass
paint steel complemented with red anodized, hair-brushed aluminum front panel for trendsetting style,
and sand-last paint steel with black anodized, hair-brushed aluminum front panel for the timeless classic
You’ve earned it. Welcome to the Headquarters!
Engineering passion & design idea
The slightest demand, the greatest satisfaction!
In headphone amplifier circuit design, some user might think more is better. In KingRex design more is not
definitely better. The HEADQUARTER (HQ-1) is the first Class A headphone amplifier with pre-out design.
The MOSFET as the heart of the HQ-1 makes the sound to be even warm and juicy. We think the vivid
dynamic and transparent ton is also another main character of the HQ-1. Some part of these character
might also need to thank for the separated HQ- PSU.
After T20 series audio amplifier appear to the public, KingRex already set the image for good power source
provider and great audio equipment designer. The first unique design is the isolated linear power supply
unit, it definitely improve the sonic performance by instant current surge providing ability and neater DC
for providing clean background.
How is the difference between switching power and linear power!
All of the amplifiers need current while them working, or there won’t be any good sonic performance as
many detail will lost. So the power source is very important for the amplifiers. There will be three power
sources most in common: switching power adaptor, linear power supply unit, and battery power supply
The switching power adaptor should be most convenience and common power source the users could
chose however it is not a good selection for music connoisseur who cares the sonic performance much
more than the obtain convenience as it has the most noise and distortion by the high-frequency switching
and harmonics in its design.
The linear power supply should be better choice for audiophiles. It has less noise and distortion than the
switching power adaptor, however, during the AC to DC conversion and rectification process, there is still
unavoidable following the unexpected noise and distortion. That’s because the AC power should pass lots
of electronic parts as transformer, diodes, voltage regulators, and components to be the lower current and
neat DC.
The linear PSU will be a great design for the HEADQUARTER (HQ-1) as the pure power could affect the sonic
performance a lot. Sometime people already spend a lot of money for a really Hi-End power supply unit.
That’s why we design one reserved PSU for it. All KingRex concern is for bring the fully enjoyment and
happy listening while using HQ-1.
Contents in this box
Headquarters headphone amplifier *1
Headquarter liner power supply unit *1
AC power cord *1
Headquarter XLR female jack DC power cord*1
User manual *1
Warranty card*1
Fully package iteam*1 (one paper carton box + 1set black recycle foam)
Safety instructions
A. Important safety instructions!
Thank you for choose KINGREX HEADQUARTERS headphone amplifier . We sincerely hope you could keep the
user manual for whole HEADQUARTERS headphone amplifier lifetime, it provides you with better protection
for connected equipment.
Please read this user manual very carefully. It provides safety, installation, and operating instructions that will
help you derive the overall performance and fully extend the life that the HEADQUARTERS has to offer.
Please save this manual! It includes important instructions for the safely use HEADQUARTERS and for
obtaining factory service should the proper operation of the HEADQUARTERS come into question.
Please save or recycle the packaging materials! The HEADQUARTERS’s shipping materials were designing with
great care to provide protection from transportation related damage. These materials are invaluable if you
ever have to return the HEADQUARTERS for service. Damage sustained during transit is not covered under the
B. Safety caution!
To reduce the risk of electric shock, disconnect the HEADQUARTERS reserved power supply unit from the
mains supply before installing the HEADQUARTERS headphone amplifier. Reconnect the power cord only
after signaling interconnections have been made.
The following precaution should be observed when working on the power supply unit:
-Remove watches, rings or other metal objects.
-Use tools with insulated handles.
!!! Caution: Risk of electric shock, do not remove cover. No user serviceable parts inside, Refer servicing to
qualified service personnel.
!!! Warning: To reduce the risk of fire, replace only with the same type and rating of fuse.
!!! Warning: To reduce the risk of fire or electric shock, install in temperature and humidity controlled indoor
area of conductive contaminants.
-Read the user manual and familiarize yourself with the functions before you attempt to use this equipment.
-To prevent fire or shock hazard, do not expose this appliance to rain or moisture.
-Do not dispose of in fire to prevent injury or burns. Also do not place the units near the heat sources such as
radiator, heat registers, stoves, or other devices (including amplifiers) that produce heat.
-Do not disassemble the machine with power on. If you do, you may receive an electric shock.
-Do not let children (or grownups) push anything into holes or slots in the case-this could result in harmful
electrical shock and could cause damage of the equipment.
-Do not set these units near the water near following area: bathtub, washbowl, kitchen sink, laundry tub, wet
basement, or swimming pool.
-Do not place heavy objects on the power cord. If the cord is damaged, fire, or electrical shock may result. In
particular, it is possible that one might accidentally place a heavy object on a carpet that covers the cord;
definitely avoid these situations!
-Do not install the HEADQUARTERS headphone amplifier in a place where it might be exposed to oil, smoke or
steam (for example, near a cooking table or humidifier). Otherwise, fire or electrical shock may result.
-Do not place the power cord near a heating device. Otherwise, the cord sheath may melt, resulting in fire or
electrical shock.
-Obstruct the necessary all- around ventilation: especially DO NOT place the set close to curtains or on soft
furnishing such as carpets. Overheating can cause unnecessary damage and shorten the lifespan of the
-No user serviceable parts inside. Refer servicing to qualified technician. Never remove the cover unless
qualified to do so. This unit contains dangerous voltage.
-When you remove the power plug, be sure to hold the plug. Never pull on the cord. Otherwise, the power
cord may become damaged, resulting in fire or electrical shock.
-Do not attempt to modify this equipment. Otherwise, fire or electrical shock may result. Warranty is void on
modified devices.
-Do not damage, process, bend, twist, stretch or heat the power cord. If the cord is damaged, fire or electrical
shock may result.
-When you are connecting other audio devices to the HEADQUARTERS headphone amplifier make sure that
you first turn off the power to all devices to be connected. Refer to the user’s guide for each device and use
the specific cable for the connection.
-Set the volume levels of all devices including that of the HEADQUARTERS headphone amplifier) to minimum
before connecting the HEADQUARTERS headphone amplifier to your actual set up and to the AC outlet.
Otherwise, an extremely loud noise could damage your loudspeakers or even your hearing.
-If you plan not to use the HEADQUARTERS headphone amplifier for a long period of time (such as when you
are on vacation), remove the power plug from the AC outlet. Otherwise, a fire could possibly result.
-If any abnormality occurs while suing the HEADQUARTERS headphone amplifier, remove the plug from the
AC outlet. In this case first shut off the power amplifier or turn down the volume controls and so on to avoid
possibly damaging transients.
- If you notice any abnormality- such as smoke, smell, noise, etc. –remove the plug from the AC outlet.
Confirm that the abnormality is no longer present, then consult your dealer for repair. If you continue using
the HEADQUARTERS headphone amplifier under abnormal condition, fire or electrical shock might result.
- If a foreign object or water enters inside the equipment, remove the plug from the AC outlet and consult
your dealer for repair. If you continue using the HEADQUARTERS headphone amplifier under this condition,
fire or electrical shock may result.
- If the power cord is damaged(for example if it is cut or if the core wire is exposed), ask your dealer for a
replacement. If you continue suing the HEADQUARTERS headphone amplifier under this condition, fire or
electrical shock might result.
-The HEADQUARTERS headphone amplifier offers superb sonic quality. To ensure the best possible results,
you should use the best quality connecting cables that you can afford. Regular maintenance involves keeping
all connections clean using a quality contact cleaner.
C. Important warning!
You must earth this machine. The PREference PSU is going through 3 wires power cord and wall ac socket.
If you cut off the mould plug, get rid of it straight away. You cannot rewire the plug it into a socket
The wires in the mains lead have the following color code:
Green and Yellow: Earth
Blue: Neutral
Brown: Live
If the wires in the main lead do not match the colors marked in your plug, do the following:
You must connect the green and yellow wire to the pin marked by the letter “ E” or by the safety ‘Earth
symbol’ or colored green and yellow or green.
You must connect the blue wire to the pin which is marked with the letter “N” or colored black.
You must connect the brown wire to the pin which is marked with the letter “ L “ or colored red.
You must have a fuse in the plug, adaptor, or at the distribution board.
The power supply cord should be rounted so that it is not likely to be walked on or pinched, especially
near the plug, convenience receptacles, or where the cord exists from the unit.
The power-supply cord of the unit should be unplugged from the wall outlet when it is to be unused for a
long period of time.
Operation environment presentation
Front panel details & rear panel details
HQ-1 in red panel color
HQ-1 in Black panel color
Connecting the cables and machine setting
Input setting & Output setting
Red panel
Black panel
Connecting the cables and machine setting
Input setting & output setting
How to operate
1. Please do not pill up the HQ-1 & HQ-1 PSU as it might be interrupted by very little noise . Please place
the HQ-1 & HQ-1 PSU in horizontal position for getting the best performance.
2. Please make sure all power connection being tight before you start use it.
Please noted the Neutrik XLR plug connection is for signal pass, please do not connect the HQ-1 PSU
with any other machines to avoid the unknown damages.
3. Please minimize the volume by VR before you replace another headphone.
4. In the early two minutes of turning up the power of HQ-1, the internal capacitors and input stage would
be reached the balance. In this status, switching the output selector will cause the sudden pulse output.
It might hurt your headphone or your power amplifier. KingRex would suggest you to do the switch 3
minutes after power on.
5. All KingRex parts and accessories are all in good quality and performance. However, we knew there still
lots of users seeking the great. Change the accessories as signal cable or power cord might have
significant efficiency. The HQ-1 & HQ-1 PSU connected power cord is specially made for reserved
purpose. The ordinary Audio XLR cable should be not suit the HQ-1 & HQ-1 PSU. For avoid the unknown
damages, please contact with KingRex or dealers before you replacing the XLR cable.
6. To maintain the consistence of the HQ-1 pre-out & phone out, KingRex sets the output level equally. The
input level might be over for most of the integrated amplifier. We would suggest you use HQ-1 with
your power amplifier.
Specification of HEADQURATERS (HQ-1)
HQ-1 headphone amplifier with outboard Power supply unit
Input Impendence: 15k Ohm Ω
1.8 Ohm
Gain :
20Hz(-0.7dB) ~ 80KHz(+0.1dB)
Output power (@1% THD+N)
100mW at 300ohm
170mw at 150 ohm
360mW at 60ohm
570m W at 30 ohm
THD + N :
0.005% at 2Vrms Output
Dynamic Range:
Separation :
>92dB at 1Khz
>76dB at 10Khz
Signal to Noise
Audio connectors: Neutrik Headphone jack (6.35mm) with gold plated contacts
RCA connectors with gold plated contacts
<10W with outboard low noise power supply
technical specification
liner power
transformer :
45W toroidal type (18V / 2.5A )
voltage requlatory
Total 8pcs Hi-Fi grade Nippon Chemicon Electrolytic capacitior in total
capacity 25100uF.
5 x 2,200 uF at AC input stage.
3 x 4,700uF at DC output stage.
AC acceptance :
110V +/- 10%
; 220V +/- 10% by area requriement
Dimension :
183 x 145 x 55 mm
Two outfit design : Black panel / Red panel
Feature of HEADQUARTERS (HQ-1)
KingRex new – HEADQUARTERS (HQ-1) is in Class A MOSFET design is general-purpose desktop headphone
HQ-1 has one input and two outputs which is selectable by front panel push button- one is line-output and
another is phone-output.
Gold-plated NEUTRIK 6.35mm headphone jack and gold-plated RCA terminals for provide great contact.
The interior circuitry consists by first stage transistor –Toshiba A970/C2240 for first stage amplification and
output stage by Hitachi MOSFET 2SK214.
Featuring Hi Fi grade Panasonic FM capacitor as main filter brings the transparent background and balanced
soundstage ; input capacitor choose WIMA increase acoustic density; output capacitor choose Vishay for
more neutral and delicate details. All material choose for neutral, balance, details, rich musicality, and vivid
Original ALPS potentiometer for provide the best signal for sonic purity.
Input/ output signal path setting use FURUKAWA PCOCC which brings more expansive and warm sound.
Discreet external linear power design- highly current supplied toroidal transformer, LMS1585 constant
voltage regulator, total 8pcs Hi-Fi grade Nippon Chemi-Con Electrolytic capacitor in total capacity 25100uF(5 x
2,200 uF at AC input stage; 3 x 4,700uF at DC output stage) through NEUTRIK
out fully power to fit active dynamic demands.
XLR socket all design stream
Two style chassis design : Chassis design by piano glass paint steel 180 x 138 x 45mm with aluminum red
anodized panel in hair polishing or Sandy blast paint steel 180 x 138 x 45mm with aluminum black anodized
panel in hair polishing.
For cleaning the cabinet, use a dry cloth and wipe dust away. If needed, moisturize the
cloth with a small amount of window cleaning dissolvent. Do not use excessive amounts of
solvents, and do not let any of solvent spill into amplifier. The front panel is made of
aluminum, it can be cleaned by using normal mild solvents and clean paper tissue or cloth.
Do not use any other the scratch the mirror display at the front.
Burn in
All new electronic equipment must be burned in to achieve optimum performance.
Please allow the new pre-amplifier and reserved power supply unit to burn in by playing
music with the loudspeakers connected for 200 hours before critical listening is performed.
The simplicity of the KingRex PREference preamplifier and reserved PSU are very few
parts can be breaking down.
Should you ever require service, you can either contact your dealer or national
distributor, who can solve any problems locally.
You are also very welcome to contact KingRex Technology Co., LTD directly if you need
any information or help.
Our contact information is listed on the last page of this user guide.
Our best wishes ~
We at KingRex only use the best “ raw materials” trimmed and rafted to perfection by
the best engineers and sound enthusiasts for all audiophiles.
The guidance lines in this manual will assure you of an exquisite sound experience
hope it will provide clear instruction to operate our products.
We hope you years of proud ownership and happy listening. We feel confident that you
will cherish this amplifier for both its amazingly clear reproduction as well as for its
splendid craftsmanship, elegant appearance, and convenient size.
Hope you won’t mind to share with us if there is any problem or questions. Please do not
hesitate to contact with us. We look forward to hearing from you~
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