Highlander Pro Acoustic Mix DI User manual

Owners Manual

The Pro Acoustic Mix DI
An Acoustic Powerhouse

Welcome
Welcome to the Highlander Pro Acoustic Mix DI and thank you for placing your
trust in Highlander Products.
The Pro Acoustic Mix DI offers a level of audio uality and versatility that until
now could only be obtained by purchasing bulky, rack mount e uipment. Whats
more, the Pro Acoustic Mix DI is small enough to fit in the accessory compart-
ment of many guitar cases and can be powered by batteries, making it com-
pletely portable (120 hours from two 9V batteries).
The Pro Acoustic Mix DI includes a Two Channel Mixer with Four Band Tun-
able EQ on each Channel, Phase Reverse Switching, Mic Power, Effects Loop,
Integrated DI (XLR, balanced output) and much more. The Ultra-Low Noise,
Extended Range Electronics deliver the ultimate in warmth and clarity. Ergo-
nomically engineered to provide unsurpassed ease of use, this is truly an Acous-
tic Powerhouse.
Taking a little time to familiarize yourself with the workings of the Pro Acoustic
Mix DI will help you gain the maximum benefit from this powerful tool.
Best wishes from the staff at Highlander.
870 CAPITOLIO WAY, UNIT 3 · SAN LUIS OBISPO, CA 93401 USA
TEL: [phone] · FAX: [phone]
U.S. & CANADA TOLL F EE: 888.658.1819
EMAIL: [email protected]
WEBSITE: highlanderpickups.com

Important Information
Retain this Manual:
The operating instructions should be read before the unit is operated.
Water and Moisture:
The unit should not be used near water (e.g. near a sink, etc.) or exposed to rain, sleet or snow.
Care should be taken so that liquids are not spilled into the enclosure.
Mechanical:
Do not expose the unit to excessive vibration including loudspeakers. Care should be taken so
that objects do not fall on the unit. The unit should not be dropped. void situations where any
cables attached to the unit could cause someone to trip and hurt themselves or cause the unit
to fall.
Heat:
The unit should not be situated in direct sunlight and should be kept away from heat sources
such as radiators, stoves or other appliances including amplifiers that produce heat.
Grounding:
The unit is grounded by the audio equipment it is plugged into. Make sure that the audio
equipment that the unit is plugged into is properly grounded.
Power Source:
The unit should be connected to a power supply only of the type described in the operating
instructions or as marked on the unit and its C dapter. Do not stand on the power cable.
Cleaning:
The unit should be cleaned using a slightly damp (almost dry) soft cloth. Do not use cleaning or
polishing products. Do not spray the unit with water or any liquid cleaners.
Non-Use Periods:
The C Power dapter should be unplugged from the outlet, and the batteries should be
removed when the unit is not going to be used for long periods of time.
Servicing:
The user should not attempt to service the unit beyond what is described in the operating
instructions. ll servicing should be referred to qualified personnel.

Contents
Quick Start .....................................................................................................6
Power and Connections ................................................................................................. 6
Basic Settings ................................................................................................................ 7
Front Panel Controls .....................................................................................8
Back Panel Connectors .............................................................................. 10
Input Channels in Detail.............................................................................. 12
Recommended Types of Pickups ................................................................................ 12
Instrument icrophones............................................................................................... 12
Channel Volume Controls ............................................................................................ 12
Channel Inserts ............................................................................................................ 12
Phase Reverse ............................................................................................................. 13
The EQ ......................................................................................................................... 13
Extended Range EQ .................................................................................................... 14
Tunable EQ .................................................................................................................. 14
Using Tunable EQ ........................................................................................................ 15
Artistic Use of EQ ................................................................................................. 15
Using EQ to deal with problems ........................................................................... 15
Pitch to Frequency able ............................................................................ 16
Examples of Pitch to Frequency conversion ................................................................ 16
Master Output in Detail ............................................................................... 17
Output Level ................................................................................................................. 17
aster ute ................................................................................................................. 17
Tuner Output ................................................................................................................ 17
The FX Loop (Special Effects) ..................................................................................... 18
Unbalanced Output ...................................................................................................... 18
Balanced Output .......................................................................................................... 18
Ground Lift Switch ........................................................................................................ 18
Unbalanced and Balanced Connections ...................................................................... 19
Unbalanced Connections ..................................................................................... 19
Balanced Connections ......................................................................................... 19
Power ...........................................................................................................20
AC Adapter ................................................................................................................... 20
Using Batteries ............................................................................................................. 20
Installing Batteries ........................................................................................................ 20
LED Power Indicator and Battery Level onitor .......................................................... 20
Block Diagram .............................................................................................22
ech Specs................................................................................................... 23
Extended Response ..................................................................................................... 23

6
Quick Start
Power and Connections
Plug in the AD18 AC Adapter (into any one of the two AC
Adapter connectors) or install two 9V Batteries and turn
on the Pro Acoustic ix DI. The LED should come on. If
batteries are being used, the LED will start slowly flash-
ing. This is normal, it saves battery power. When the bat-
teries need to be changed the LED will flash quickly.
PA or Recording Console Tuner Acoustic Instrument
Amplifier
AC Adapter
XLR (Balanced) Cable Guitar Cable
Guitar Cable
Guitar Cable
Instrument 1 Instrument 2
Stereo/ ono
Guitar Cable
Remember to mute or turn down the console
and/or amplifier before plugging in any cables.
Plug in instrument or instruments (two max).
If Instrument 1 has two pickups or a pickup
and mic, use a stereo cable and do not plug
in a second instrument. If a stereo cable is
being used, the pickup that is wired to the tip
will be connected to Channel 1.
uick Start
30 feet to 250 feet long

7
Basic Settings
Connect Instrument ics that require power to Channel 2.
The  IC PWR button should be DOWN to turn on ic Power.
Highlanders Internal ic does Not Require ic Power.
A) DOWN
(Power ON).
C) UP (not
muted).
These knobs have no
effect until the EQ
faders are moved up
or down from center.
F) ove Channel 1
Volume up to this
position.
H) Bring aster
Volume up
slowly until the
instrument is
loud enough.
B) Set all 8 EQ faders to the
center (detent) position. In this
position the EQ is bypassed.
G) For a second pickup or
instrument bring up
Channel 2 Volume.
D) UP (not muted).
E) UP for two pickups,
pickup and mic or two
instruments. DOWN for
one instrument.
The Master Mute: utes the signal from both outputs but
leaves the tuner signal on.
The Channel Mutes: utes the channel and the tuner signal.
Phase: Both phase buttons
should be in the UP position
(not phase reversed).
uick Start

8
Front Panel Controls
1) Channel Volume: Controls the loudness of each channel. Typically set between half
way and all the way up, depending on how loud the source (pickup) is.
lFor an instrument with two pickups or a pickup and a microphone like our IP-2 and
Internal ic, the Channel Volume controls can be used to adjust the balance be-
tween both sound sources.
lIn situations where two instruments are connected (one to each channel), the vol-
ume of each instrument can be adjusted independently.
The controls for both Input Channels are identical with the exception of ic Power on
Channel 2, therefore, only one set of controls is detailed.
Use Channel 2 with either a pickup or an Electret (Instrument) icrophone.
ic Power on Channel 2 is NOT REQUIRED for Highlanders Internal ic.
The EQ will be explained in detail in the chapter on Using Tunable EQ.
Front Panel Controls
124
3
6 8 10 11
579 171615
12 13 14

9
2) LO (Bass) Boost/Cut: Center position is off (no EQ). See page 13 The EQ.
3) Tune (sweep) the LO Pitch: Typically set at 40Hz for acoustic guitar.
4) LO Mid Boost/Cut: Center position is off (no EQ). See page 13 The EQ.
5) Tune (sweep) the LO Mid Pitch: See Using Tunable EQ on page 15 for settings.
6) HI Mid Boost/Cut: Center position is off (no EQ). See page 13 The EQ.
7) Tune (sweep) the HI Mid Pitch: See Using Tunable EQ on page 15 for settings.
8) HI (Treble) Boost/Cut: Center position is off (no EQ). See page 13 The EQ.
9) Tune (sweep) the HI Pitch: For acoustic guitar set between 12KHz to 24KHz
10) Channel Mute: Turns the sound from the channel off including the output to the tuner.
lNote: The aster ute mutes the output but leaves the tuner on. If two instru-
ments are being used, and one is being tuned, the other instrument can be muted
to avoid leakage into the tuner.
11) Channel Phase: Phase reverse can be used to correct for two pickups (or a pickup and
a microphone) that are out of phase with each other. When two pickups are out of
phase, the sound from the instrument will get thinner (less bass) as the two pickups are
mixed. Reversing the phase of one of the two pickups will correct this situation. Gener-
ally, the pickup that is considered to be secondary has its phase reversed. In some
instances switching the phase can reduce or eliminate feedback. See page 13 Phase
Reverse.
12) Mic Power on Channel 2 only: Used to power Electret Condenser (Instrument) ics.
lNot Required for Highlanders Internal ic
13) Master FX: Controls the loudness of a special effect (e.g. reverb) that is connected to
the effects loop.
14) Master Volume: Controls the overall loudness. Set between half way and all the way up.
lWhen setting up, first bring the Channel Volume ¾ (75%) of the way up. Bring the
aster Volume up slowly until a suitable level is obtained. If the aster Volume is
all the way up and there is not enough level, bring up the Channel Volume.
15) Master Mute: Turns off the signal coming from both the ¼ output jack and the XLR
(Balance Out) while leaving the signal from the Tuner Output on, so an instrument can
be tuned up without audience participation.
16) LED Power Indicator:
lWhen using the AC Adapter, this LED is on continuously when the unit is On.
lWhen using batteries, this LED will come on for a few seconds then start to flash
approximately once every 3 seconds. This saves battery power.
lBatteries should last for approximately 120 hours (thats 60, two-hour gigs). The
LED will start flashing faster (once a second) when the batteries need changing.
17) Power Switch: This turns the unit On and Off. Always make sure the amplifier or PA
that the Pro Acoustic ix DI is connected to is muted or turned down before turning
the power On or Off.
Front Panel Controls

10
Back Panel Connectors
When connecting to either the ¼ Output Jack or the XLR Balanced Out, make sure the
amplifier or PA you are connecting to is turned all the way down or muted.
18) Channel 1 Input Jack: This is a stereo ¼ jack that can be used in two ways.
lStereo: An instrument with 2 pickups or a pickup and mic that are wired to a stereo
output jack can connect both pickups to both Input Channels using a stereo cable.
The Tip connects to Channel 1. The Ring connects to Channel 2.
lono: An instrument with one pickup can be connected using a regular (mono)
guitar cable.
19) Channel 2 Input Jack: This is a mono ¼ jack for connecting to Channel 2.
lUse this input when using two instruments that each have a single pickup.
One instrument is plugged into Channel 1, the other into Channel 2.
lOr to use Channel 2 instead of Channel 1.
20) Channel 1 Insert: Enables an effect to be inserted into Channel 1. This is a stereo ¼
jack; Send is on the Tip, and Return is on the Ring. A stereo to 2 mono insert cable is
available from Highlander.
21) Channel 2 Insert: Enables an effect to be inserted into Channel 2. This is a stereo ¼
jack; Send is on the Tip, and Return is on the Ring. A stereo to 2 mono insert cable is
available from Highlander.
Back Panel Connectors
18
1921
20
23252728
2224
2629
Input
Channels
aster
Output

11
22) Master FX Send: ¼ mono jack for connecting to the input of an effects unit such as
reverb.
23) Master FX Return: ¼ mono jack for connecting to the output of the effects unit.
24) Master Unbalanced Output: ¼ mono jack for connecting to the unbalanced input on
equipment such as an acoustic instrument amplifier, certain power amplifiers or pow-
ered speakers.
25) Tuner Output: Connect to the input of a tuner. The Tuner Output stays on when the
aster ute is active. The Tuner Output is muted by either of the Channel utes.
26) Master Balanced Output (DI): A 3-pin XLR connector for connecting to a PA, record-
ing console, certain power amplifiers or powered speakers.
27) Ground Lift Switch: Disconnects the ground connection to the XLR (Balanced Out)
connector. Used to prevent hum caused by ground loops. Use the switch in whichever
position provides the quietest connection.
lUP is ground lifted.
lDOWN is grounded. Default position is down. Always try this position first.
28) AC Power Adapter Input: (see 29)
29) AC Power Adapter Input: Do Not Plug In 2 AC Adapters Simultaneously.
The batteries are disconnected when the AD18 AC Adapter is plugged in.
lEither connector (28) or connector (29) can be used to plug in the AD18 AC Adapter.
There are two connectors making it possible to power more than one Pro Acoustic
ix DI from a single AD18 AC Adapter using a Power Jumper Cable available from
Highlander.
lUse Highlanders AD18 AC Power Adapter Only.
lContact Highlander to purchase alternate AC Adapters for countries that use volt-
ages other than 120VAC.
Back Panel Connectors

12
Input Channels in Detail
Recommended Types of Pickups
The Pro Acoustic ix DI is designed to give optimal audio performance when used with Active
or low impedance pickups.
lActive pickups have a matching preamplifier and require power, typically a 9V battery.
lLow impedance pickups are normally magnetic sound hole pickups.
High impedance pickups such as piezo pickups without a matching preamplifier are not rec-
ommended. These pickups may work but will probably sound thin. The low noise and low distor-
tion inherent in the Pro Acoustic ix DI will not be fully realized.
Instrument Microphones
There are a wide variety of Electret Condenser icrophones available for acoustic instrument
amplification. Unfortunately, there is no standard method for powering these mics. The Pro
Acoustic ix DI has a unique and innovative microphone power circuit (see page 8, control 12)
on Channel 2. This circuit senses the power requirements of almost every (two wire) type of
Electret ic available and delivers optimal power for each type of microphone.
lWhen running from batteries, battery life will be reduced when using a powered mic. This
varies according to the power requirements of the mic.
lic Power is not intended for Studio Type Condenser icrophones like the AKG 414, etc.
lic Power is Not Required for Highlanders Internal ic.
Channel Volume Controls
A fader (1) on each channel. There are two basic uses for these controls:
lWhen an instrument is equipped with two pickups or a pickup and microphone (such as
Highlanders IP-2), these two controls can be used for balancing the sound from both sources.
lWhen using two instruments (each with a single pickup), the volume of each instrument
can be set to the appropriate level. If a solo musician is using both instruments, the levels
can be left in the appropriate positions, and the Channel utes can be used to select a
particular instrument.
The optimum position for these controls depends on the type of instrument, pickup and playing
style.
Tip: If the aster Volume has to be kept below half way, try turning down the Input Channels
until the aster Volume is at least half way up.
Channel Inserts
Connectors (see page 10, connectors 20 & 21) are used to insert an effect into each channel.
Bass Players sometimes use Channel Inserts to insert a compressor. The main difference be-
tween a Channel Insert and an Effects Loop is that when using a Channel Insert, the entire
signal is passed through the (inserted) effect (which may compromise the audio quality), whereas
with an Effects Loop, the effect is mixed with the original signal, therefore, there is no risk of
degrading the original signals audio integrity.
Input Channel in Detail

13
lBoth insert jacks are stereo. Send is on the Tip. Return is on the Ring. A stereo to 2
mono cable is required to connect to an effect unit. The Tip is connected to the effects
input, the Ring is connected to the effects output (see diagram).
lIt is possible to use the Channel Insert as a direct output from each channel. A cable is
required that has a stereo plug on one end and a mono plug on the other end. The
stereo plug has the Tip and Ring connected together and wired to the Hot of that cable.
The mono plug is wired as normal (see diagram).
Phase Reverse
A push button (11) that reverses the phase of the signal when pushed. Phase Reverse can
be used to correct for two pickups (or a pickup and a microphone) that are out of phase with
each other. This can happen if the pickups or mics have been purchased from different
manufactures or modified by a previous owner. When two pickups are out of phase, the
sound from the instrument will get thinner (less bass and less volume) as the two pickups
are mixed. Reversing the phase of one of the two pickups will correct this situation. Gener-
ally the phase is switched on the pickup that is considered to be secondary. In some in-
stances switching the phase can reduce or eliminate feedback. If two pickups are being
used the phase of both have to be switched to determine if there is any effect on feedback.
The E
Each channels EQ has four sections LO, LO ID, HI ID and HI. Each section has two
controls: a fader (or slider) (2,4,6,8) for boosting and cutting and a (rotary) knob (3,5,7,9) for
tuning (selecting pitch). When a fader is in the center (neutral) position, that section of the
EQ has no effect on the sound. The center position has a detent or click that positively
identifies the neutral position. Pushing the fader up from center boosts and pulling down
from center cuts.
When using any EQ, in order to achieve the lowest levels of noise and distortion, it is better
to cut than to boost.
Input Channel in Detail
(Tip) (Ring)

14 Input Channel in Detail
In order to discuss EQ, it necessary to understand that what engineers call frequency and musi-
cians call pitch actually refer to the same thing. usicians refer to a pitch as a note, for example,
A whereas engineers refer to a frequency in cycles per second for example 440Hz (1Hertz or
1Hz is one cycle per second). any musicians are familiar with A 440 where A refers to a
musical note and 440 refers to 440Hz. Engineers use KHz (kilohertz) as a kind of shorthand for
a thousand cycles per second. (See the Pitch to Frequency Table on page 16).
Extended Range E
Unlike many other equalizers the range of frequencies on the Pro Acoustic ix DI extends down
to 25Hz in the bass end and up to 24KHz in the treble end. There is a good reason for this.
lAt the bass end, 82.4Hz is the frequency of the low E string on a guitar in open tuning at
concert pitch. any EQs have their bass frequency preset around 80Hz. If 80Hz is boosted,
the low E string is actually getting louder and the string balance suffers. By setting the
bass frequency between 25Hz  40Hz, the bass harmonics are boosted, warming up the
sound, while maintaining string balance even if the guitar is in drop D or C tuning.
Being able to boost or cut 25Hz is especially useful for bass instruments.
lTech Note: The Input Channel; low end is rolled-off at 15Hz using a phase linear filter to
avoid boosting subsonic frequencies when the EQ is set to 25Hz.
lAt the treble end many EQs are preset between 10KHz  12KHz. Boosting these pitches
can result in a harsh, edgy sound. By boosting 24KHz, the high end sounds open and airy
without any harshness. Although the human ear cannot hear 24KHz, we are sensitive to
harmonics that are accentuated by boosting this frequency. This is a subtle but very musi-
cally pleasing effect that has been used by some of the worlds top recording engineers for
many years.
Tunable E
Tuning the EQ means that it is possible to select which pitch to boost or cut as opposed to
having the pitch preset by the manufacturer of the EQ. This flexibility enables a musician to tune
the EQ to produce exactly the desired effect or compensation. Because it is impossible to select
just one pitch, the user should be aware that pitches close to the one that is selected will also be
affected but to a lesser degree that the center or selected pitch.
There are two types of tunable EQ available on the Pro Acoustic ix DI:
lShelving EQ: The LO and HI sections of the EQ are called shelving filters.
For the LO (bass) end that means that the pitch that is selected and every pitch below
it are affected.
For the HI (treble) end the selected pitch and every pitch above it are affected.
Notch EQ: The LO ID and HI ID sections of the EQ are called notch filters. This
means that the selected pitch is affected more than the pitches that are just above
and below the selected pitch.
The terms Shelving and Notch are derived from looking at a graph used by sound engineers that has
pitch from bass to treble along the horizontal axis and loudness on the vertical axis. If you plot the response
of these types of EQ on such a graph, one looks like a shelve and the other looks like a notch.

15
Input Channel in Detail
Using Tunable E
EQ is basically used in two ways. One use is artistic, enhancing the sound of an instrument or
modifying the sound of the instrument to better suit a piece of music. The other reason for
using EQ is to deal with problems, compensating for a bad sounding room or instrument or for
dealing with feedback in a room that has less than ideal acoustics.
The most important tool when using E is the ear of the user.
Artistic Use of E
The most common use of EQ is to boost or cut the bass or treble. As discussed above, there
are ways to do this with extended range EQ that are subtle and musical. With tunable EQ it is
possible to experiment. For example, lets say a bass boost is required. ove fader (2) up
from center until the effect is heard then try rotating the EQ tuning knob (3) until the desired
sound is achieved. The same holds true for a treble boost or cut using fader (8) and knob (9).
Both mid range sections of the EQ can have very interesting effects and the user is encour-
aged to experiment, just remember that when experimenting, boosting can cause feedback.
Practice at low volume can save ears and speakers.
Using E to deal with problems
Feedback is the most common problem that EQ is used to deal with. Several factors are
involved in inducing feedback: the shape and size of the room, the materials the room and
stage are made of, speaker placement and the loudness or volume of the PA. Before deciding
to use EQ to solve a feedback problem, here are few tips on some of these other factors:
lSmall rooms are more likely to induce feedback than large ones. Keep the volume down
in small rooms.
lIf possible cover reflective surfaces like a tiled floor with a rug, if there are windows in the
room close the curtains. If temperature, outside noise and neighbors are of no concern,
then open the windows.
lPlace the main PA speakers at either end of the stage, well in front of the performers, just
above the heads of the audience and pointed straight ahead. Experiment with speaker
placement, sometimes moving a speaker a few feet to the left or right can have a pro-
found effect on feedback, especially in odd-shaped rooms. If monitor speakers are used,
then point them at the side of the instrument, not the top or back.
lIf the stage is boomy, place any speakers or instrument amplifiers that are on the stage
up on a stand or chair. If possible cover the stage with a rug.
lAs long as the people in the back of the room can hear the performance, use the lowest
volume possible.
If all else fails, it is time to resort to EQ. This is where the LO ID and HI ID sections of the
EQ come into play.
lThe performer should be in position on stage with their instrument connected to the Pro
Acoustic ix DI, (which should be connected to the PA).
lWith Channel Volume (1) down, bring up the aster Volume (14) to about ¾ of its travel.
lBring up the Channel Volume (1) slowly until the onset of feedback then back off slowly
until the feedback stops.

16
lIf the pitch of the feedback is low, then bring up the LO ID fader (4) a little and rotate
the tuning knob (5) until the onset of feedback. By rotating the tuning knob, the pitch of
the feedback is determined.
lPull fader (4) below center to reduce feedback and bring up the Channel Volume. It
should now be possible to raise the Channel Volume higher than before. As the Chan-
nel Volume is raised, EQ fader (4) may have to be brought down some more. Listen to
the sound of the instrument while pulling EQ fader (4) down. Too much cut can cause
the sound of the instrument to suffer.
lIf a different pitch starts to feedback, follow the same procedure as above with the
appropriate EQ section.
Input Channel in Detail
Pitch to Frequency Table
Examples of Pitch to Frequency conversion
G = 196Hz
D = 293.7Hz
A = 440Hz
E = 659.3Hz
andolin in Open Tuning
E = 82.4Hz
A = 110Hz
D = 146.8Hz
G = 196Hz
B = 246.9Hz
E = 329.6Hz
Guitar in Open Tuning
The following table may be helpful when using Tunable EQ:
E = 41.2Hz
A = 55Hz
D = 73.4Hz
G = 98Hz
Double Bass in Open Tuning

17
The ASTER OUTPUT is the section of the Pro Acoustic ix DI where both Input Channels are
combined (electronically mixed). The aster Output Fader (14) drives both the Unbalanced (24)
and Balanced (26) outputs. The ASTER section provides an input for the FX return and an
overall mute.
Output Level
The level (loudness) from the aster Output is controlled by fader (14) marked VOL. Generally this
control should be set between half way to three quarters of the way up. In some instances, espe-
cially when driving a professional power amplifier and speakers, it may be necessary to set this
control all the way up. Instrument Amplifiers and PA systems typically require less level than pro-
fessional power amplifiers, although each time the Pro Acoustic ix DI is used with a new system,
the optimum operating levels should be carefully determined. When determining the optimum
level, it is important to test the system by playing the loudest parts of the performance while paying
particular attention to any meters or clipping lights on consoles or amplifiers that are connected
to the Pro Acoustic ix DI. It is undesirable and potentially damaging to overdrive equipment. A
little experimentation in order to obtain the optimum, cleanest sound is in the best interest of the
user, the audience and the equipment.
When initially setting up:
lBring the aster Fader (14) all the way down.
love the appropriate Channel Volume faders (1) to approximately ¾ way up.
love the aster Fader (14) up a little and play, check the level and repeat until the desired
volume is attained.
If the aster Fader (14) is less than ½ way up and the sound is loud enough, either:
lBring down the volume of the Instrument Amp, Power Amp, PA or recording console that the
Pro Acoustic ix DI is connected to
lOr bring down the Channel faders on the Pro Acoustic ix DI
Then bring up the aster Fader until it is at least half way up.
Master Mute
When in the down position this button (15) mutes (turns off) both the Balanced (26) and Unbal-
anced (14) outputs, however, it does not mute the output to the tuner (25) (see Tuner Output).
Tuner Output
Use this ¼ jack (25) to connect the Pro Acoustic ix DI to a tuner.
The Channel utes and the aster ute have different effects on the tuner output:
lThe Channel utes mute the tuner.
lThe aster ute does not mute the tuner.
The aster ute enables instruments to be discretely tuned up (without the audience hearing). By
using the Channel utes, a musician who has two instruments plugged in can tune either instru-
ment while muting the other to prevent it from leaking into the tuner and causing false readings.
Master Output in Detail
Master Output in Detail

18
The FX Loop (Special Effects)
The FX Loop is a combination of an output or FX Send, an input or FX Return and FX Fader
that enables the user to mix a special effect (e.g. reverb or echo) with the sound of the instru-
ment. A portion of the signal from both Channels is combined (electronically mixed) and con-
nected to the FX Send Jack. The amount of signal from each Channel is determined by the
level of each Channels Fader (1). The FX Return is connected to the FX Fader, which in turn
is routed to the aster Output ixing Stage.
Note: The FX Return can be also be used as an extra instrument input, although there is no
EQ, Phase Reverse or separate ute.
Connecting the Pro Acoustic ix DI to a special effects unit:
lThe FX Send (22) is connected to the input of an effects unit.
lThe FX Return (23) is connected to the output of the effects unit.
lThe FX Fader (13) is used to adjust the desired loudness of the effect.
When using the FX loop, it is important that the special effect unit in question only passes the
wet, or effect signal and does not include any of the dry or original signal.
Unbalanced Output
Output Jack (24) is for connecting to equipment that has unbalanced (mono) inputs, e.g.
Instrument Amplifiers. There are some Power Amplifiers and Powered Speakers that may also
be equipped with unbalanced inputs. This output may be used to connect to a console if it is in
close proximity (within 25 feet) to the Pro Acoustic ix DI and has unbalanced line inputs.
Balanced Output
Output Jack (25) and the Ground Lift Switch (27) alleviate the need for a DI Box when
playing live on stage or in any situation where there is a considerable distance (more than 20
- 30 feet) between the Pro Acoustic ix DI and the piece of equipment it is being connected to.
Ground Lift Switch
Use the GND LIFT switch (27) to prevent ground loops (see Unbalanced verses Balanced
Connections on page 19) that can cause a low frequency hum. It does this by disconnect-
ing ground from the XLR connector. Use whichever switch position results in the cleanest
sound with the least hum.
lUP is Ground Lifted
lDOWN is grounded. This is the default position. Always try this position first.
Note: Because the Pro Acoustic ix DI does not obtain a ground connection from the AC
outlet, ground loops are more likely to occur when both outputs (24 and 26) are connected to
different pieces of equipment.
Master Output in Detail

19
Unbalanced and Balanced Connections
The following definitions may help to clarify the discussion on unbalanced and balanced con-
nections.
lShield in an audio cable is a series of thin, uninsulated wires that are wrapped or braided
around the hot wire to prevent electromagnetic interference from imposing noise on
the audio signal.
lElectromagnetic interference radiates from many sources including: Light Dimmers,
Computers, Radio, Cell Phones, TV, AC Wiring, Flourescent Lighting, Electric otors
and even sun spot activity.
For the purpose of this discussion the main difference between an unbalanced and a bal-
anced signal is:
lOne hot wire and shield are used to transmit the unbalanced signal. Shield is a neces-
sary part of signal transmission and is connected to ground to shield the signal from
unwanted interference.
lTwo wires are used to transmit a balanced signal. The shield is connected to ground in
order to protect the signal from interference but is not a necessary part of signal trans-
mission.
There are pros and cons to both of these strategies:
Unbalanced Connections
lUnbalanced connections in general are more accurate, especially where very high pitches
and/or fast, percussive signals are concerned. Percussive signals refer to the spike or
transient that is created, for example, when a guitar string is struck by a pick.
lTypical unbalanced cables are less expensive.
lUnbalanced signals are more prone to (electromagnetic) interference when cables longer
than 20 - 30 feet have to be used.
lWhen using a PA where the PA Console and the stage gear may be plugged into different
AC outlets, a phenomenon known as a ground loop can cause unacceptable levels of low
frequency hum. Because an unbalanced signal uses grounded shield as a necessary
part of signal transmission, ground loops cannot easily be overcome.
Balanced Connections
lBalanced connections are almost impervious to (electromagnetic) interference and can
be used over distances of a hundred feet or more.
lBecause balanced connections do not use ground as a necessary part of signal trans-
mission, ground loops are easily overcome. All that is required to prevent a ground loop is
to disconnect or lift ground at one end of the balanced cable. This can be accomplished
in the Pro Acoustic ix DI by the use of the GND LIFT Switch (27).
lTypical balanced cables are more expensive.
lSystems using balanced connections do so out of practical necessity, although under
certain circumstances there is no substitute for a balanced connection. The unbalanced
connection has the potential for better audio fidelity.
Master Output in Detail

20
Po er
Power
The Pro Acoustic ix DI is turned on using the Power Button (17). When the Power Button is
down, the unit is on.
Power can be supplied in one of two ways:
lBy using the AD18 AC Adapter
lBy installing two standard 9V batteries
When the AD18 AC Adapter is plugged in, the batteries are automatically disconnected.
AC Adapter
The AD18 AC Adapter is designed to operate several Pro Acoustic ix DIs (and/or equipment
that Highlander may produce in the future). Therefore, there are two AC Adapter Sockets (28 &
29). Either socket can be used to plug in the AD18. The other socket can be used with the
optional AC Jumper Cable to daisy chain several units to one AD18. The AD18 supplies AC
voltage which is converted to DC in the unit.
Important: Do Not Plug 2 AC Adapters.
Using Batteries
Use two standard 9V batteries. Alkaline batteries are preferred, they provide long life and stable,
low noise operation. Battery life is approximately 120 hours (thats 60, two-hour gigs), although
this can vary depending on the type of batteries used and how old they are when purchased.
Also, the use of Instrument icrophones that require power from the Pro Acoustic ix DI will
reduce battery life.
Please dispose of all batteries in an environmentally responsible manner. Check with your local
recycling center for information on the correct procedure for used battery disposal.
Installing Batteries
Fig 1 - Fig 4 indicate how to open the battery compartment. Once it is open, remove the old
batteries (if any) and disconnect them. Connect two new batteries and install them in the battery
compartment.
Avoid pulling hard on the battery wires.
Note: While changing batteries, it is OK to place the Pro Acoustic ix DI upside down on a flat
surface. The controls are protected.
LED Power Indicator and Battery Level Monitor
The Red LED (16) lights when the Pro Acoustic ix DI is turned on. This LED has three modes
of operation.
lWhen using the AD18 AC Adapter, the LED will stay on continuously.
lWhen operating from batteries, the LED will flash slowly at a rate of approximately one
flash every 3 seconds.
lWhen operating from batteries that are low on power, the LED will start to flash faster,
at a rate of approximately one flash per second. When this first happens, the batteries
are still usable but should be changed within four hours. This enables the user to finish
playing a gig, but the batteries should be replaced before the next gig.