Neutral X-DREi User manual

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NEUTRAL AUDIO wants to thank you for the trust you have placed
in us by purchasing this product and we hope it will fill you with
satisfaction for a very long time.
You should know that we have made every effort to be an exclusive
and unique audio industry leader, with our advanced analog
technology.
Signed J. M. Jimenez

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Important safety instructions
oPlease read all the instructions.
oDon’t use this equipment in humid environments.
oDo not use cleaning fluids. Use a dry or slightly damp cloth.
oDo not install near any heat sources or equipment that generates much heat.
oInside there is no component that needs adjustment. Do not handle it, and refer to
qualified service personnel in case of failure to prevent electrical accidents.
oPlace the equipment on a flat surface with enough space for ventilation
oDo not cover rear ventilation vents.
oBefore connecting the power outlet, be sure that you have the proper
voltage and the earth is of good quality.
oContact with Neutral Audio for any question not contained in this guide.
oAlways disconnect the amplifier before handling connecting cables.
This product has been assembled by hand in Spain, member of the European Community.
Audio and D.R.E.I. Neutral technology are trademarks and may not be used without
permission from the owner. The system D.R.E.I. technology is patented and cannot be used
without having been licensed by the owner.
This NEUTRAL AUDIO electric device has been
Certified for use with the integrate D.R.E.I. system
technology.

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INDEX
A short description of the external module, 4
Alternative connection, 9
Built to Last, 5
Connecting X-DREI, 5
Designed by D.R.E.I. technology, 5
Everything is analog, 5
Front, 10
Guarantee conditions, 15
Headphones amplifier, 14
Important safety instructions, 2
Inputs lines, 6
Multi-buffers, 5
Note for technicals experts:, 16
Output to amplifier, 7
Recommended connection, 7
Switch on of equipment, 10
Synergy Control, 11
Technical features, 16

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A short description of the external module
In the first place we are proud that NEUTRAL AUDIO is a part of your highly valued musical
system. With this external Module DREI, Stereo and Analog, we have taken a big step
forward in the audio industry.
This new and essential product is designed to increase the listening quality of your
stereo audio and movie soundtracks, to levels well beyond currently normal. Our sound
will give you many more hours of warm, friendly enjoyment. If the rest of your audio
system is at an appropriate level, we are convinced that it will sound more neutral,
transparent, detailed, warm and musical than you could ever have imagined.
A preamplifier is the element in the music reproduction system that lets you select the
source you want to hear, to change its output level or volume and connect to the
associated amplification. Neutral Audio is aware that this is the step where the musical
signal deteriorates most due to the extremely low levels with which they work and the
electrical problems inherent in this and therefore should be chosen with great care as
overall outcome of the entire system depends on it. For this reason we
developed the Multi Pre amplification technology, which with several preamps
modules in parallel per channel commanded by the DREI module the problems we have
talked about are greatly reduced obtaining a pure sound you will never have
heard before. There are several Neutral Audio Multi-preamp models with DREI tech. and
they are undoubtedly the best choice if you want to have the best sound possible, as they
have been designed from scratch to eliminate any electronic interaction in the sound signal.
The X-DREI is not a preamp. It is designed for those cases in which there may not be
a need or desire to replace the existing preamplifier but where there is a desire to
include the DREI technology in the final sound. To do this it is necessary
to insert this external module between your preamp output and the amplifier input.
Internally it uses a simplified Multi-preamps technology , using 6 high-precision buffers
operating in parallel with no gain or volume control and controlled by the incorporated DREI
with the objective of neutralize intermodulation, correct errors in the electronics and
increase the overall performance of the amplification, filters and speakers.
PRO AUDIO, in this sector this device has an important use in indoor or outdoor concerts
and nightclubs and the extraordinary control it exercises over power and amplification allows
higher sound levels without saturating rooms, produces fewer problems of sound
transmission to adjacent rooms and floors and increases the intelligibility of the music. Less
power is needed to achieve the required sound level, therefore facilitating compliance with
acoustic regulations, increasing acoustic efficiency and extending the life of the power
equipment and speakers thus increasing their profitability. In Recording studios the
properties our technology confers to the sound is reflected in the Master.
The audio tone is not modified, it keeps the characteristic "sound" of your equipment but at a
much higher level.
The main function is as described but has other interesting features:
You can change the soundstage using an external switch.
It includes a high end headphone amplifier,(only in the HighEnd version).
It’s an active adapter between input and output RCA-balanced which does not
cause deterioration in the musical signal.
You can use it as a split for bi-amping your speakers or to a second system in
another room.
In the interior,(on the exterior in the Pro model), there is a switch to change into
Duplex mode, thus quadrupling its output and doubling the X-DREI effect using
only one input per device.
Bypass. When Off it bypasses input to output completely unchanged.

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Designed by D.R.E.I. technology
The insertion of the D.R.E.I. technology module, (described at the end of this manual),
included in all the analog models manufactured by Neutral Audio makes our products
exceptional and us pioneers because our devices incorporate this technology.
To bring out the full power of "humanizing" sound and reducing electronic interactions that
this module is able to offer, Neutral Audio has had to develop new amplification circuits and
ingenious solutions to adapt them to each other.
For more information please visit our website.
Multi-buffers
Similar to a prism that separates white light into many colors, DREI tech separates sound
into several musical signals and redirects them to 6 high precision buffers operating in
parallel to finally get back to the stereo signal. Each of these buffers is managed by the
DREI module.
It is a simplified circuit of the Multi-preamp, patented by the brand.
Do not confuse multi-channel systems used in home theatres with our product, which
is only STEREO, even though we use various amplifiers per channel.
Everything is analog
One of the fundamental aspects of the X series and its exceptional sound is that it does
not use any digital devices at any point and shows utmost respect to content. We have
exclusively used analog technology; there is no digitalization used in any process.
Built to Last Being top-level equipment, its construction and design has been done without cost
concessions of any kind. We have used the most modern means available to make each
of the component parts, using first quality components, the printed circuit boards and the
connectors are gold plated, the toroidal transformer is sealed and isolated, and Premium
electronic components etc.
The audio signal does not use internal wires and the signal track has been reduced to
minimum on a single circuit board.
Sturdy, durable, anodized aluminum chassis in the HighEnd model and a high strength
treated steel and aluminum chassis in the PRO model
Connecting X-DREI
CAUTION. Before making connections, turn off the associated amplification and
disconnect the plug from the outlet.
Make sure the voltage of the device matches that of your power supply. For safety the

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earthing of your electrical system must work properly; otherwise unwanted noise and
interference may invade the audio system.
Note that the unit when off connects "bypass”, the input signal is directly available to the
output connecting RCA/RCA and XLR/XLR. After switching on, the blinking blue power LED
lights dimly until all internal modules are operational, (5 sec. approx.), after which it gives a
stronger light and DREI tech. starts to function, (CHECK LED in the PRO model). This is not
a fault but protects your speakers from inappropriate signals.
We strongly recommend you to use good quality, clean, dry, rust
free interconnect cables. Periodically check the status of these connections.
Our connections are very high quality and gold
plated. We recommend periodic application of
a specific product, (ask the dealer), to the
connectors to prevent rust and loss of contact.
Balanced connections of input and output XLR
connectors are the standard in
The pin 1 = Ground
The pin 2 = Hot
The pin 3 = Cold
Inputs lines
The equipment has a pair of RCA inputs, (only in the HighEnd version) and another pair of
XLR (balanced). You can connect either one or the other. Normally, you use only one of
them.
In the case of connecting two different devices, (ex. Stereo and AV), in the two inputs
simultaneously, it is usual that the sound of the two mix at the start and do not cause
damage. In some cases there may be no sound output, usually in the unit connected to a
RCA input.
You should connect the left channel to the "LEFT" (white) and the right channel to the
"RIGHT" (red), but this is not obligatory.
It is normal for the balanced (XLR) input
signal to be louder than the RCA and this is
not a malfunction. XLR also has a higher
output volume level (+6 db.) than the RCA.
Output gain
Input
Output
STEREO
MONO
RCA
RCA
=
=
RCA
XLR
+6 db
+6 db
XLR
RCA
-6 db
=
XLR
XLR
=
+6 db

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Recommended connection
The usual and recommended way to connect the X-DREI in your current stereo system is as
shown in the illustration above.
The X-DREI is inserted between the preamplifier and amplifier. In this mode with a single
appliance, the X-DREI serves all the sources used.
At the input you can connect any preamp of any brand, transistor or valve, or any source
(CD player, DAC, etc.) but it is very important that it has VOLUME CONTROL.
Remember that this device does not have any gain or volume control, so the volume level of
the output is the same as the input. If you connect a source directly, the sound is very
loud and could damage your speakers.
Output to amplifier
You should connect the output marked "OUTPUTS" directly to the respective amplifier and
can use any unbalanced connections (RCA) or balanced (XLR), since both are always
active and deliver the same signal.

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•If you have active speakers directly connect the X-DREI at the input to the internal
amplifier.
•For bi-amping your speakers connect the RCA to the amplifier of middles and trebles
and the XLR (balanced) to the bass amplifier. Note that this product is not a filter and
the entire musical signal is on both outputs. You may need to adjust the internal gain
of the amplifiers.
•To connect a second system in another room use the RCA for the nearest amplifier
and Balanced (XLR) to the farthest.
•For a duplex system in mono, connect only one input to the corresponding left
channel and use any of the four outputs in the desired configuration. Repeat with
another X-DREI on the other channel. The advantages of this configuration are
obvious when looking for the complete separation of channels, including separate
preamps as in the case of model X-QUANTUM Neutral Audio. Do not forget to
change the internal switch to “mono”.
•The output is muted when you connect headphones.
DUPLEX/MONOPHONIC MODE
To set this up in mono reposition
the internal switch found inside the
HighEnd Model or the outside
MONO switch on the PRO model.
Only can connect the Left input.
Before opening the lid
DISCONNECT the device from the
energy supply to keep you safe
from injury.

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Alternative connection
There is another way to connect the X-DREI into your current stereo system, indicated in the
illustration above, although it is generally less efficient than the previous way. It inserts the
X-DREI between a source and preamp. It is not necessary that the source has a volume
control.
You may wish to connect it this way for various reasons, including:
•Do not want any of your sources to be directed to the DREI (although you can always
turn it off thanks to its internal bypass).
•You want to set a different soundstage in each source.
•To enhance the sound with several X-DREI, both on the inputs and the outputs.
•To send a source to two preamplifiers.
•To have a headphone amplifier from a single source.
•To get an extra output for recording.
At the input you can connect any source whether transistor or valve from any manufacturer.
Remember that this device does not have any gain or volume control, so the volume level of
the output is the same as the input.
Do not connect in this way, unless the connected source has a volume control,
directly to an amplifier or the sound will be very loud and could damage your speakers.

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Finally there is another possible connection
mode, the Loop Tape. If your preamp has
an input / output recording tape, you can
connect the X-DREI here as indicated in the
instruction manual of your preamp, as if it
were a recording system, processor or
equalizer.
Front
As you can see the design of the X-DREI is extremely simple, as befits a device of its range
where ease of use and high sound quality should dominate.
While "off" the bypass redirects each input to its output (RCA-RCA and Balanced-Balanced).
There is no change in the connected equipment's impedance values when in bypass.
Switching on the equipment
If you've already got to here, you must have the equipment fully installed, tested and
connected.
It is common sense to avoid damage to your speakers by turning the amplifier stage on last,
and also switching them off first!
When you press the power button located on the rear panel, the blue LED will light dimly.
After a while, when all the internal modules are stabilized, the LED will light up brightly,
indicating that it is fully operational.

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Synergy Control
One of the advantages of the technology developed by Audio Neutral is that it allows you to
vary the impulse response of each of the various buffers that make up each channel.
Thanks to this unique and novel technique the Synergy and Soundstage can be adapted to
your taste with a simple click in the position of the switch.
What led Neutral Audio to design this feature is very important. Bear in mind that the
room/hall where music is played always alters the overall sound. Depending on the physical
characteristics and elements of the room/hall and the type of speakers you have in your
installation, the resulting sound can be far from ideal. It would be endless to explain all the
possible situations and that is not the goal of this manual but generalizing, all equipment +
room/hall may deliver a less crisp and more confused sound with severely uncontrolled base
areas with little detail, in addition to lack of amplitude and focus on the stage, including lack
of "life" and realism. All this can be improved by using this device.
To achieve maximum synergy between
the room/hall and your High End
equipment (especially the speakers), try
using the different positions (6) by turning
the switch to the one that best suits your
preferences. There is no need to turn off
the appliance.
Inherited from our Multi-preamps, we
have continued with the colour system for
ease of use but on this occasion have
intermediate positions between the
different colours to achieve a greater
setting accuracy.
The last position (red) is where you will
least notice the effect of Synergy change
and will be the closest to your current
installation. The DREI tech always operates at 100% and its effects are independent of this
adjustment.
Our recommendation is not to make any radical changes in the beginning. For example start
at Blue (No. 3) and eventually turn the switch until you reach the optimal position. You might
be interested in other positions when using different sources. The button design makes it
easy to change without seeing it.
This image will help you select the position you like best. The following explanations should
not be taken too literally as they are only intended to explain as simply and graphically as

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possible what to expect from this technology and its results will largely depend on the
associated elements and listening quality of the room/hall.
As you can see in our example, the Green position gives you a close sound, with great base
detail and only the first wave reflections the middles and trebles will be clean and
straightforward, widely spaced and with plenty of air between the instruments as might be
perceived by an orchestra director. Everything seems to become otherworldly and listening
becomes pleasanter and less tiring.
On Blue you will seem to move back a few rows into the audience, the bass will become
more present and more instruments are fused together. The soundstage becomes a bit
narrower.
In Red the feeling of the room/hall becomes more present. The reverberations seem to
increase, the bass becomes more powerful and confused and some details are lost. The
middles and trebles attenuate because of the effect of the stored energy, in general the
room/hall and the speakers are more easily saturated and the sound pressure level can’t be
so high and produces more listening fatigue.

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Headphones amplifier
As a bonus, the X-DREI HighEnd model has a high performance internal headphone
amplifier to take advantage of the DREI technology in this sphere.
The connection is made with a standard 6.35mm, (1/4 "), stereo Jack
On introducing the headset plug, the music signal is diverted to the headphone amplifier
and the output disconnects the speakers. To avoid damaging it, the signal is never
connected to the headset when they are not connected.
The orange LED light indicates that the headset is connected.
It has been equipped with a high gain of 15 db, so we recommend that you turn down the
volume on your amp before connecting. It is designed to prevent your speakers from being
damaged by excessive dbs when you unplug the headphones.
Because of the special characteristics of D.R.E.I. technology we recommend you not use
sharp sounding headphones. It is better to have a flat natural response.

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Guarantee conditions
NEUTRAL AUDIO guarantees this product for a period of 2 years, or the time
legally established in the country where it is purchased, as long as it is
purchased from an authorized dealer.
This guarantee covers any manufacturing defects.
To qualify for this guarantee, you must go to a service centre authorized by
NEUTRALAUDIO or the store where you purchased it, presenting your
purchase invoice.
The Guarantee DOES NOT COVER:
oDamage caused by accident, misuse or abuse.
oDamage caused by external factors or natural tragedies.
oTheft or robbery.
oDamage caused by handling by persons not authorized by NEUTRAL AUDIO.
oDamage caused by other non-product components.
oProducts purchased from unauthorized distributors.
oThe shipment rates for the repair and return of the device to the customer.
oAny costs arising from installation or desinstallation of the product.
Any manipulation of the product by any person not authorized by NEUTRAL AUDIO,
automatically makes this guarantee null and void.
Consult your distributor as to your nearest technical assistance provider and how to
contact him.

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Technical features
All technical specifications contained in this manual are correct at the time of printing.
However NEUTRAL AUDIO may have made modifications to them without notice.
Line RCA unbalanced and XLR balanced
RCA line outputs unbalanced and XLR balanced
Frequency response 0-200000 Hz (extended up to 500,000 Hz)
Total Distortion 0.04%
Recommended maximum input voltage 3.2Vpp RCA / 6.2Vpp balanced
Maximum output voltage Vpp 3.2Vpp RCA / 6.2Vpp balanced
Input impedance 20 Kohms RCA / 50 kohms balanced
Output impedance 600 ohms RCA / 300 Ohm balanced
Signal to noise ratio better than 110 dB
Channel separation better than 100 dB
Headphone amplifier 15db.
IEC socket for power supply
Maximum Consumption> 6 W
Supply voltage 230VAC 50/60Hz. (or 115VAC),(using an interior switch).
Dimensions HighEnd Width: 305 mm, Depth: 261 mm, Height: 85 mm
Approximate HighEnd Net Weight 4.5 kg
Dimensions PRO model standart 19" 1U
Approximate PRO model Net Weight 3.8 kg
For more information contact your local Neutral Audio distributor .
Note for technical experts:
This unit challenges the traditional method of the electronic measurement of sound. If you want to correctly
interpret these values, consider talking to Neutral Audio regarding them.

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NOTES:

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