DigiDesign PRE User manual

PRE
™
Version 8.0

Legal Notices
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reserved. Under copyright laws, this guide may not be
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Digidesign.
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Warning
This product contains chemicals, including lead, known to the
State of California to cause cancer and birth defects or other
reproductive harm. Wash hands after handling.
Communications & Safety Regulation Information
Compliance Statement
The model PRE complies with the following standards
regulating interference and EMC:
• FCC Part 15 Class A
• EN55103 – 1, environment E4
• EN55103 – 2, environment E4
• AS/NZS 3548 Class A
• CISPR 22 Class A
Radio and Television Interference
This equipment has been tested and found to comply with the
limits for a Class A digital device, pursuant to Part 15 of the
FCC Rules.
Communications Statement
This equipment has been tested to comply with the limits for a
Class A digital device. Changes or modifications to this product
not authorized by Digidesign, Inc., could void the Certification
and negate your authority to operate the product. This product
was tested for CISPR compliance under conditions that
included the use of peripheral devices and shielded cables and
connectors between system components. Digidesign
recommends the use of shielded cables and connectors
between system components to reduce the possibility of
causing interference to radios, television sets, and other
electronic devices.
Safety Statement
This equipment has been tested to comply with USA and
Canadian safety certification in accordance with the
specification of UL Standards : UL6500 and Canadian CAN
E60065. Digidesign Inc., has been authorized to apply the
appropriate UL & CUL mark on its compliant equipment.
Warning!
Important Safety Instructions
When using electric or electronic equipment, basic precautions
should always be followed, including the following:
• Read all instructions before using this equipment.
• To avoid the risk of shock, keep this equipment away from
rain water, and other moisture. Do not use this equipment
if it is wet.
• The equipment should only be connected to the correct
rating power supply as indicated on the product.
• Do not attempt to service the equipment. There are no
user-serviceable parts inside. Please refer all servicing to
authorized Digidesign personnel.
• Any attempt to service the equipment will expose you to a
risk of electric shock, and will void the manufacturer’s
warranty.
• The product should be connected only to the correct power
supply as indicated on the product.
• Do not block any ventilation openings. Install in accordance
with the manufacture’s instructions.
• Do not install near any heat sources such as radiators,
heat registers,stoves, or other apparatus (including
amplifiers) that produce heat.
• Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades with
one wider than other, A grounding type plug has two blades
and a third grounding prong. The wide blade or the third
prong are provided for your safety. If the provided plug does
not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
• Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
• Only use attachments/accessories specified by the
manufacturer.
• Clean only with dry cloth.

Contents iii
contents
Chapter 1. Introduction to PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PRE Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
What’s Included . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
System Requirements and Compatibility Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Digidesign Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Conventions Used in This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
About www.digidesign.com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 2. Hardware Overview and Stand-Alone Operation. . . . . . . . . . . . . . . . . . . . . . . 5
PRE Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
PRE Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Using PRE in Stand-Alone Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Calibrating PRE and Other Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Adjusting Channel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Adjusting Input Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Muting Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Chapter 3. Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Connecting PRE to a Pro Tools System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Configuring AMS for PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Configuring MIDI Studio Setup for PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Configuring Pro Tools Software for PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Mic Preamps in Pro Tools Edit and Mix Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Viewing Mic Preamp Controls in Pro Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Mic Preamp Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Mic Preamp Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Adjusting Mic Preamp Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Adjusting Controls on Multiple PREs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Mic Preamp Remote Control with Digidesign Control Surfaces. . . . . . . . . . . . . . . . . . . . . . . . 31

PRE Guideiv
Appendix A. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Appendix B. Pinout Diagram for the PRE DB-25 Connector . . . . . . . . . . . . . . . . . . . . . 39
DB-25 Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Appendix C. MIDI Controller Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
PRE MIDI Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Chapter 1: Introduction to PRE 1
chapter 1
Introduction to PRE
Welcome to the Digidesign®PRE™ multi-pur-
pose microphone preamplifier for Pro Tools®
systems.
PRE is designed especially for use with Pro Tools
systems, but it can also be used as a stand-alone
microphone preamplifier. When used with
Pro Tools, most PRE features can be controlled
from within the Pro Tools application.
With or without remote control, PRE can be
configured manually using its front panel
switches and displays.
PRE can also be remotely-controlled by other
MIDI devices through standard MIDI controller
data. See Appendix C, “MIDI Controller Num-
bers.”
PRE Features
• Eight high-performance, discrete matched
transistor hybrid microphone preamplifica-
tion circuits
• Remote control with qualified Pro Tools TDM
systems and Digidesign control surfaces (such
as D-Control®, D-Command®, C|24™, Com-
mand|8®, Control|24™, and ProControl™)
• Industry-standard DB-25 output connectors
for easy connection to Pro Tools audio inter-
faces or any other recording or mixing me-
dium
• Each channel features:
• Support for microphone (XLR), line level
inputs (1/4-inch), or direct instrument
(1/4-inch)
• Selectable impedance settings for Mic input
• Input gain variable from 0 dB to +69 dB, in
approximately 3 dB steps, with an optional
–18 dB pad
• +48V power for condenser microphones
• Balanced Insert points (Send and Return),
for easy integration of outboard gear (such
as compressors or EQs)
•Phaseinvert
• 85 Hz High-Pass Filter
• Up to nine PREs supported through software
for up to 72 channels of remote-controlled
preamplification
• All features available in Stand-alone mode
What’s Included
•PREunit
•ACpowercable
•PREGuide
• Digidesign Registration Information Card

PRE Guide2
System Requirements and
Compatibility Information
When used as a stand-alone microphone pream-
plifier, PRE is ready to use.
For remote control within Pro Tools, PRE
requires:
• A Digidesign-qualified Pro Tools|HD®
system
• A Digidesign-qualified MIDI interface
Mic Preamps in Pro Tools can be remotely
controlled by Digidesign control surfaces.
Digidesign can only assure compatibility and
provide support for hardware and software it has
tested and approved.
For complete system requirements and a list of
Digidesign-qualified computers, operating sys-
tems, hard drives, and third-party devices, refer
to the latest information on the Digidesign web-
site:
www.digidesign.com/compatibility
Digidesign Registration
Review the enclosed registration information
card and follow the instructions on it to quickly
register your purchase online. Registering your
purchase is the only way you can be eligible to
receive complimentary technical support and
future upgrade offers. It is one of the most im-
portant steps you can take as a new user.
Conventions Used in This
Guide
All Digidesign guides use the following conven-
tions to indicate menu choices and key
commands:
:
The following symbols are used to highlight
important information:
Convention Action
File > Save Choose Save from the File
menu
Control+N Hold down the Control key
and press the N key
Control-click Hold down the Control key
and click the mouse button
Right-click Click with the right mouse
button
User Tips are helpful hints for getting the
most from your Pro Tools system.
Important Notices include information that
could affect your Pro Tools session data or
the performance of your Pro Tools system.
Shortcuts show you useful keyboard or
mouse shortcuts.
Cross References point to related sections in
this guide and other Digidesign Guides.

Chapter 1: Introduction to PRE 3
About www.digidesign.com
The Digidesign website (www.digidesign.com) is
your best online source for information to help
you get the most out of your Pro Tools system.
The following are just a few of the services and
features available.
Product Registration Register your purchase
online. See the enclosed Digidesign Registration
Information Card for instructions.
Support and Downloads Contact Digidesign
Technical Support or Customer Service; down-
load software updates and the latest online
manuals; browse the Compatibility documents
for system requirements; search the online An-
swerbase; or join the worldwide Pro Tools com-
munity on the Digidesign User Conference.
Training and Education Study on your own using
courses available online or find out how you can
learn in a classroom setting at a certified
Pro Tools training center.
Products and Developers Learn about Digidesign
products; download demo software or learn
about our Development Partners and their plug-
ins, applications, and hardware.
News and Events Get the latest news from
Digidesign or sign up for a Pro Tools demo.
Pro Tools Accelerated Videos Watch the series of
free tutorial videos. Accelerated Videos are de-
signed to help you get up and running with
Pro Tools and its plug-ins.
To learn more about these and other resources
available from Digidesign, visit the Digidesign
website (www.digidesign.com).

PRE Guide4

Chapter 2: Hardware Overview and Stand-Alone Operation 5
chapter 2
Hardware Overview and Stand-Alone
Operation
This chapter describes the PRE front and back panels, and includes instructions for using its switches,
indicators, and connectors for Stand-alone mode operation. To use PRE in Remote mode (remote con-
trol of PRE by Pro Tools or a dedicated control surface), see Chapter 3, “Remote Operation.”
PRE Front Panel
PRE has the following front panel switches, indicators, and connectors:
Power Switch and LED Ring
This switch turns PRE on and off. When lit
(green), the LED ring around the power switch
indicates that the unit is switched on.
By default, PRE powers up in Stand-alone mode.
In this mode, controls can be adjusted from the
front panel or remotely. The Remote “Lock-
Out” LED is unlit (signifying Remote Lock-Out
mode is inactive).
At power up, PRE units default to the last set-
tings they had at power down, with the excep-
tion of Remote Lock-Out mode.
PRE front panel
Activity and Remote LEDs
Channel Select and Mute
switches and LEDs
Shift, Oscillator, and
MIDI Chan switches
Line/Inst 1 and 2
Gain/Param
Power switch,
and LED ring
Peak Meter
Clear Clips
Peak Hold, Source,
and Input Impedance
Signal Present/Clip, 48V, Insert, Pad,
Phase, and High-Pass Filter indicators
48V, Insert, Pad, Phase,
and High-Pass Filter

PRE Guide6
Activity LED
When lit (green), this LED indicates MIDI data is
being received by PRE.
Remote “Lock-Out” LED
When lit (green), this LED indicates PRE is in Re-
mote Lock-Out mode. In this mode, PRE is con-
nected to a remote controller (such as Pro Tools
or a dedicated device), and the front panel con-
trols are locked out.
PRE is placed in Remote Lock-Out mode (after
configuring PRE for remote control) by selecting
Remote Lock-Out Mode in the Mic Preamps tab
of the Pro Tools Peripherals dialog.
PRE can be taken out of Remote Lock-Out mode
by deselecting the Remote Lock-Out Mode box
in the Pro Tools Peripherals dialog, or by power-
ing PRE off, and then back on.
For more information on locking and unlocking
PRE front panel controls, see Chapter 3, “Re-
mote Operation.”
Shift Switch and LED
This switch (along with the channel Select
switches) is used in Stand-alone mode when
grouping channels in order to control multiple
channels simultaneously. When lit (green), this
LED indicates the Shift switch is active.
OSC (Oscillator) Switch and LED
This switch enables the internal oscillator,
which can be used for calibrating the inputs of
audio interfaces (such as Digidesign’s
192 I/O™). When lit, the OSC LED indicates the
oscillator is on.
The oscillator generates a fixed tone of approxi-
mately 1k Hz at +4 dBu (= 1.228 Vrms).
The PRE oscillator signal can be routed through
the OSC output on the back of the unit or
through individual channels on the DB-25
connector.
To route the signal to the OSC output:
Press the OSC switch on the front of the unit.
To route the signal through an individual channel
output on the DB-25 connector:
1 Disconnect any cable inserted into the chan-
nel’s Send jack.
2 Enable the Insert for that channel via the front
panel (see “Insert Switch and LEDs” on page 9)
or through software.
3 Press the OSC switch on the front of the unit.
The oscillator signal can only be activated via
the front panel. However, routing the oscillator
signal through the DB-25 connector can be con-
trolled remotely or by the front panel.
Calibration can change with temperature.
The output is nominally +4 dBu, but may
vary up to ± 0.3 dB depending upon the
current operating temperature. Allow the unit
to warm up and stabilize the oscillator output
before using it for calibration purposes.
Oscillator routing through a channel output
is done after the channel’s metering point,
and therefore does not display in the PRE
meters.

Chapter 2: Hardware Overview and Stand-Alone Operation 7
MIDI Chan (Channel) Switch and LED
This switch activates MIDI Channel selection
mode. When lit, the MIDI Chan LED indicates
PRE is in MIDI Channel mode, and the PRE’s
MIDI channel can be changed with the
Gain/Param control.
Gain/Param Display
This three-character, seven-segment LED dis-
plays the input gain for the currently selected
PRE channel, or the PRE’s MIDI channel.
This display can also show the current firmware
version of PRE.
To display the firmware version of PRE in the
Gain/Param display:
1 Press Shift once, then release it.
2 Press OSC.
Gain/Param Control
The Gain/Param control can be used to add gain
to the input signal on one or more of the PRE’s
eight channels, or to set the PRE’s MIDI chan-
nel. Changes made with the Gain/Param control
appear in the Gain/Param display.
The gain range for each input (Mic, Line, and In-
strument) is 0 dB to +69 dB, adjustable in incre-
ments of approximately 3 dB (see Table 2 on
page 44).
Peak Meter
These fourteen-segment LEDs indicate input sig-
nal level for any channel that currently has its
Select switch enabled. If multiple channels have
their Select switch enabled, only the left-most
channel will be represented in the Peak Meter
display.
The meter is referenced from the clip point of
the amplifier (for example, –22 dB is 22 dB
below the clip point of the amplifier).
Clear Clips Switch
This switch clears Clip indicators on the Peak
meter and Signal indicators.
Peak Hold Switch and LEDs
This switch sets the clip hold action of the SIG
meters atop each of the 8 channels. Clips are
also indicated by a red Clip LED on the Peak
Meter. The amount of time the clip stays lit is
determined by the Peak Hold value, as follows:
Off When lit, the Peak Hold function is off. Clip
LEDs will light during clipping, then clear
shortly after clipping stops. This is the default
Peak Hold value, on power up.
3 sec When lit, Clip LEDs are displayed for
three seconds, then automatically clear, as long
as no additional peaks occur.
∞(Infinity Symbol) When lit, Clip LEDs will stay
lit until the Clear Clips switch is pressed.
To change Peak Hold (time constant)
performance:
Press Peak Hold once to change to the next
setting, or multiple times to toggle through the
three settings. Peak hold is a global command
which sets clip persistence for all channels.

PRE Guide8
Source Switch and LEDs
This switch sets the active input source for indi-
vidual PRE channels to Mic, Line, or Inst (instru-
ment). The three Source LEDs indicate the active
input.
Input Impedance (Represented as Z)
The Input Z switch sets the input impedance for
a PRE channel to 1.5 kΩ, 15 kΩ, or 1.5 MΩ.
The three Input Z LEDs indicate the current set-
ting:
1.5K Typically used for microphone inputs, this
is the default setting when Source is set for Mic.
15K Typically used for line level inputs, this is
the default setting when Source is set for Line.
1.5M Typically used for instrument inputs, this
is the default setting when Source is set for Inst.
To change input impedance, do one of the
following:
If the input Source is Mic, press Input Z once
to change to the next setting, or multiple times
to toggle through the three settings.
If the input Source is Line, press Input Z to
change to 1.5K or 15K.
If the input Source is Inst (instrument), the In-
put Z cannot be changed from its default 1.5M
setting.
Channel Status Section
Each PRE channel provides switched control for
48V (phantom power), phase reverse, input pad,
access to a unity gain insert send/return, and a
high-pass filter. In addition, all eight channels
have individual Mute switches and signal status
LEDs.
Signal Present/Clip (SIG) LEDs
These LEDs indicate the status of a channel’s in-
put signal. Green indicates signal is present
(–45 dB) and red indicates clipping. When there
is no signal present or the signal is below –45 dB,
the LED is off.
When clipping occurs, the LED remains lit or
clears, depending on the Peak Hold setting.
Clips can also be manually cleared with the
Clear Clip switch.

Chapter 2: Hardware Overview and Stand-Alone Operation 9
48V Switch and LEDs
This switch applies 48V phantom power to the
Mic Inputs. When lit (red), these LEDs indicate
which channels have 48V enabled.
Mic Inputs can provide 48V phantom power for
microphones that require it to operate. If Source
is set to Line or Inst, phantom power automati-
cally disengages to avoid sending phantom
power back to the line level device through the
XLR cable, eliminating unnecessary power draw
when not in use for powering microphones.
Dynamic microphones (like a Shure SM57) do
not require phantom power to operate, but are
not harmed by it. Most condenser microphones
(like an AKG C414) do require phantom power
to operate. If you are not sure about the phan-
tom power requirements for your microphone,
contact the manufacturer, or read your micro-
phone’s documentation.
Insert Switch and LEDs
This switch enables insert points on individual
channels. When lit (yellow), Insert LEDs indi-
cate which channels have their insert point en-
abled.
PRE’s back panel has eight pairs of send and re-
turn jacks for inserting external processors (such
as compressors or EQs) in the audio path. Insert
send levels are post output trim.
Pad Switch and LEDs
This switch applies an input pad to individual
channels to reduce input sensitivity by –18 dB.
When lit (green), Pad LEDs indicate which
channels have Pad enabled.
Phase Switch and LEDs
This switch applies phase reversal to individual
channels. When lit (green), Phase LEDs indicate
which channels have phase reverse enabled.
High-Pass Filter Switch and LEDs
This switch applies a high-pass filter to individ-
ual channels. When lit (green), HPF LEDs indi-
cate which channels have the high-pass filter
enabled.
Each PRE channel includes a high-pass filter
with a center frequency of 85 Hz and a roll-off of
–18 dB/octave. Use the high-pass filter to re-
move microphone proximity effects, hum, rum-
ble, wind, and other low frequency sounds.
Although phantom power can be used
safely with most microphones, ribbon mi-
crophones can be damaged by it. Always
turn off phantom power, and wait for the
red 48V indicator light to go completely off
and any signal to dissipate before connect-
ing or disconnecting a ribbon microphone.
Condenser microphones requiring phantom
power should not be “hot-plugged” into a
PRE Mic Input where phantom power is
active before plugging the microphone in.
This could potentially cause damage to
PRE, as well as to un-muted monitoring
systems, due to a loud “click” or “pop.”

PRE Guide10
Channel Mute Switches and LEDs
Each PRE channel has a dedicated Mute switch
to mute input signal. The respective Mute LED
lights when muting is enabled.
Channel Select Switches and LEDs
These switches are used to “focus” one or more
channels to adjust their controls. When lit
(green), the Channel Select LED indicates that
the channel’s controls can be adjusted.
To select multiple channels for adjusting, first
press the Shift key on the left-hand side of the
unit, then press the Select switches for corre-
sponding channels. To return to single channel
selection, disengage the Shift key, then press the
Select switch for the individual channel you
wish to change.
The following channel controls can be adjusted:
• 48V Phantom Power; see “48V Switch and
LEDs” on page 9.
• Phase Reverse; see “Phase Switch and
LEDs” on page 9.
• Pad; see “Pad Switch and LEDs” on page 9.
• Insert; see “Insert Switch and LEDs” on
page 9.
• High-Pass Filter; see “High-Pass Filter
Switch and LEDs” on page 9.
• Mic/Line/Instrument Source Switching; see
“Source Switch and LEDs” on page 8.
• Input Gain; see “Gain/Param and Input
Gain” on page 15.
When PRE is powered off, channel select states
are stored in memory and are subsequently re-
stored at power up.
Line/Inst 1 and 2
The front panel includes two 1/4-inch
balanced/unbalanced TRS jacks, with Tip wired
hot (or “+”), Ring cold (“–”), and Sleeve ground.
These jacks mirror Line/Inst Inputs 1 and 2 on
the back panel. Connecting to the front panel
Line/Inst input will break a connection made to
the respective back panel Line/Inst input.
Use these jacks for convenient access to high im-
pedance instrument inputs.

Chapter 2: Hardware Overview and Stand-Alone Operation 11
PRE Back Panel
PRE has the following back panel connectors:
Mic Inputs 1–8
These are balanced XLR jacks, with Pin 1 wired
ground, Pin 2 wired hot (or “+”), and Pin 3 wired
cold (or “–”).
Use these jacks for microphone connections or
for line level devices that support balanced XLR
connectors.
Line/Inst (Line Level/Instrument)
Inputs 1–8
These are balanced 1/4-inch TRS jacks, with Tip
wired hot (or “+”), Ring cold (“–”), and Sleeve
ground.
Unbalanced connections are supported with the
use of standard 1/4-inch mono phone plugs. If
using line inputs with balanced line level de-
vices, be sure to use balanced to balanced cables
to maximize performance.
DB-25 Outputs 1–8
This is a balanced DB-25 connector for line out-
puts 1–8. For pinouts, see Appendix B, “Pinout
Diagram for the PRE DB-25 Connector.”
This connector can also output a fixed oscillator
signal on each channel. For more information,
see “OSC (Oscillator) Switch and LED” on
page 6.
Send and Return Inserts 1–8
These are balanced 1/4-inch TRS Send and
1/4-inch TRS Return jacks, with Tip wired hot
(or “+”), Ring cold (“–”), and Sleeve ground. In-
sert send levels are post output trim.
Use these jacks for inserting external devices
such as compressors or equalizers in the audio
path before recording to disk. Sends can also be
used as line outputs; in this case, all front panel
controls will affect the signal, except Mute.
Return channels 1–8 can be bypassed from the
front panel, or through remote control.
PRE back panel
Send and Return Inserts 1–8
Mic Inputs 1–8 Line/Inst Inputs 1–8
DB-25 Outputs 1–8
Output Trims 1–8 MIDI In/Out/Thru
Oscillator Output
Auto-switching power
supply connector

PRE Guide12
Output Trims 1–8
The output trims are used to individually cali-
brate each channel’s output and send level.
The output trims are factory-calibrated so that
the clip point of the PRE output amplifier
matches the factory-set clip point of the 192 I/O
analog input. The PRE’s output level is –6 dBu
below its maximum output of +28 dBu
(+22 dBu). If you do not intend to use a 192 I/O,
you should turn the trims all the way up (clock-
wise) to allow for maximum signal output
(+28 dBu) and maximum performance.
MIDI In/Out/Thru Connectors
The MIDI connectors on PRE accept standard
5-pin MIDI cables.
The MIDI In connector accepts MIDI input for
remote control of PRE (for example, from the
MIDI Out of a MIDI interface in a Pro Tools
system).
The MIDI Out connector sends MIDI data out of
the PRE to the MIDI input of a Pro Tools system,
or another PRE. To daisy-chain multiple PREs,
connect the MIDI Out of one PRE to the MIDI In
of the next PRE, and so on. You will also need to
set each unit to a unique MIDI channel number
(refer to “MIDI Connections” on page 18).
The MIDI Thru connector is not used for
Pro Tools remote control.
Oscillator (OSC) Output
This is a balanced 1/4-inch TRS jack that outputs
a fixed oscillator signal (+4 dBu reference signal
at approximately 1 kHz) for calibrating the in-
puts of gear not connected through the DB-25
output. For more information, see “OSC (Oscil-
lator) Switch and LED” on page 6.
AC Power
This connector accepts a standard AC power ca-
ble (included). PRE is auto power-selecting
(100V to 240V) and will automatically work
with a standard modular cable to connect to AC
power receptacles in any country.
Power Up Defaults
When you first power on PRE, it has the follow-
ing settings.
User Settings Stored in Memory
When PRE is powered down, it remembers its
last settings. When the unit is powered back on,
the last settings will be intact.
The Send jacks and the DB-25 connector
both use the output trims for adjustment.
Calibrating a DB-25 output will affect the
Send output level as well.
Power Up Defaults
Function Status
Operation
Mode
Stand-alone (Remote “Lock-Out”
LED off)
Peak Hold Off
OSC Off
Shift Off

Chapter 2: Hardware Overview and Stand-Alone Operation 13
Using PRE in Stand-Alone
Mode
PRE can be used without Pro Tools as a stand-
alone microphone preamplifier. PRE stand-
alone operation requires power and audio
‘connections.
Powering Up PRE
To use PRE as a stand-alone microphone
preamplifier:
1 Connect AC power to PRE.
2 Power on PRE.
At power up, PRE units will default to the last
settings they had at power down.
Making Signal Connections to PRE
Depending on how you plan to use PRE, the way
you connect it to your studio will vary.
While you can use PRE with a variety of audio
setups, all you really need is a line input device
(such as a mixer or an A/D converter) to monitor
PRE outputs.
Connecting Audio Sources
To connect a microphone:
1 Press the Channel Select switch for the Mic In-
put you will be using.
2 Change the input source to Mic, by pressing
Source one or more times.
3 Make sure the gain is turned down, especially
if the monitors are up.
4 Verify that phantom power (48V) is disabled.
Press the 48V switch, so that the 48V LED is off.
5 Plug a microphone directly into the Mic Input
on the back of PRE. These inputs accept XLR
connectors.
6 If your microphone requires phantom power,
press 48V.
7 Turn the Gain/Param control to raise the gain.
Use the Peak Meter to determine the proper
level.
If the output trim has been calibrated to the in-
put trim of your 192 I/O, the pre-fader meter in
Pro Tools should accurately reflect the Peak
Meter of the PRE, allowing you to use the on-
screen meters to set your levels.
8 Repeat these steps for additional microphone
connections.
To prevent damage to PRE or your monitor-
ing system, mute your monitoring system or
set levels to their minimums before making
audio connections. This will prevent sudden
spikes and surges, as well as possible feed-
back if a microphone is connected and left
“open.”
Although phantom power (48V) can be
used safely with most microphones, some
ribbon microphones can be destroyed by it.
You should always turn off phantom power,
and wait for the red light to go completely
off before connecting or disconnecting a
ribbon microphone.

PRE Guide14
To connect line level and instrument level sources:
1 Press the Channel Select switch for the
Line/Inst Input you will be using.
2 Change the input source to Line or Inst by
pressing Source one or more times.
3 Plug a line level source (such as a synth, out-
put from your mixer, or a microphone or guitar
that has been amplified by an outboard preamp)
or a DI (direct instrument) source into a
Line/Inst Input on the front or back of PRE.
These inputs accept balanced/unbalanced TRS
connectors.
4 Repeat these steps for additional connections.
Using External Devices
PRE can make dedicated connections to external
analog devices (such as compressors and equal-
izers) before committing the signal to disk in
Pro Tools. You can send and return signals to
these devices, using PRE’s back panel Send and
Return jacks.
To connect an external analog device to your
system:
1 Connect the Send jack of one PRE channel to
an input of the external signal processor.
2 Connect the output of the external signal pro-
cessor to the Return jack of the same PRE
channel.
3 Press the Channel Select switch for the
Send/Return channel you will be using.
4 Press Insert.
Repeat these steps for additional connections.
Calibrating PRE and Other
Devices
Before you use PRE, you may want to calibrate
its output level (as well as the input and output
levels of other devices) to the level of your mix-
ing console.
The output trims are factory-calibrated so that
the clip point of the PRE output amplifier
matches the factory-set clip point of the 192 I/O
analog input. The PRE’s output level is –6 dBu
below its maximum output of +28 dBu
(+22 dBu). If you do not intend to use a 192 I/O,
you should turn the trims all the way up (clock-
wise) to allow for maximum signal output
(+28 dBu) and maximum performance.
If using line inputs with balanced line level
devices, be sure to use balanced to balanced
cables to maximize performance.
Both the Send and Return jacks are balanced
1/4-inch jacks, with Tip wired hot (or “+”),
Ring cold (“–”), and Sleeve ground. Insert
send levels are post output trim.

Chapter 2: Hardware Overview and Stand-Alone Operation 15
Adjusting Channel Controls
Most PRE parameters can be changed with front
panel channel control switches; for a descrip-
tion of each switch, see “PRE Front Panel” on
page 5. Input Gain is changed with the
Gain/Param control (see “Adjusting Input Gain”
on page 16).
PRE channel controls can be applied to one or
more channels at a time.
To select one channel:
Press the Select switch of the desired channel.
Selecting one channel deselects the previously
selected channel or channels.
To select multiple channels:
Hold Shift and press the Select switch of any
channels you want to adjust.
When more than one channel is selected, meter-
ing, control states, and Gain/Param settings
reflect the activity of the leftmost channel of the
group.
Adjustments made to any selected channel are
made to all selected channels. See “Mixed State
Operating Mode While Editing Multiple Chan-
nels” on page 15.
To change a setting with a channel control switch:
1 Select one or more channels.
2 Press a channel control switch to change its
current setting. For example, if the 48V LED is
off, pressing 48V will enable 48V phantom
power on all the selected channels. (48V can
only be enabled when input source is set for Mic
input. It is disabled as a choice when input
source is set for line or DI input.)
To return the selection to a single channel:
Press Shift to disengage, then press the Select
switch of the individual channel you want to
edit.
Mixed State Operating Mode While Editing
Multiple Channels
A mixed state operating mode exists when you
are editing multiple channels simultaneously,
and some of the channels have different set-
tings.
Channel Control Switches
When multiple channels are selected, switch
modifications made to one selected channel are
automatically applied to all selected channels.
Gain/Param and Input Gain
If an offset exists between selected channels, the
offset will be maintained while moving the
Gain/Param control until you reach +69 dB
gain or 0 dB, at which point the selected chan-
nels will mirror each other.
To quickly select all channels, drag your
finger across all the Select switches.
Gain offsets are retained when multiple
channels are adjusted in Stand-alone mode,
but not in Pro Tools Remote mode.

PRE Guide16
Adjusting Input Gain
To set input gain on a channel:
1 If the Gain/Param display currently shows a
MIDI channel, press MIDI. The display should
now show an input gain level.
2 Press the Select 1 switch (for example, for Mic
Input 1).
3 If the Source Mic LED is not lit, press Source
one or more times until the Mic LED is lit (so
that the Mic Input is active).
4 Rotate the Gain/Param control to change the
input gain level.
Muting Channels
To mute a channel:
Press the Mute switch on each channel you
want to mute. To mute additional channels,
press their corresponding Mute switches. Meters
remain active, and Channel Status controls can
still be changed.
To unmute a channel:
Press Mute again.
To quickly mute all channels, drag your
finger across all the Mute switches.