DigiDesign PRE User manual

Digidesign
2001 Junipero Serra Boulevard
Daly City, CA 94014-3886 USA
tel: 650·731·6300
fax: 650·731·6399
Technical Support (USA)
tel: 650·731·6100
fax: 650·731·6384
Product Information (USA)
tel: 650·731·6102
tel: 800·333·2137
International Offices
Visit the Digidesign Web site
for contact information
Web Site
www.digidesign.com
PRE
Guide
Remote Controllable 8-Channel Mic Preamp

Copyright
This guide is copyrighted ©2002 by Digidesign, a division of
Avid Technology, Inc. (hereafter “Digidesign”), with all rights
reserved. Under copyright laws, this guide may not be
duplicated in whole or in part without the written consent of
Digidesign.
DIGIDESIGN, AVID and PRO TOOLS are trademarks or
registered trademarks of Digidesign and/or Avid Technology,
Inc. All other trademarks are the property of their respective
owners.
All features and specifications subject to change without
notice.
PN 910609434-00 REV A 06/02
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Chapter 2. PRE Hardware Overview and Stand-Alone Operation . . . . . . . . . . . . . . . . . . 5
PRE Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
PRE Back Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Using PRE in Stand-Alone Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Calibrating PRE and Other Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Editing Channel Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Adjusting Input Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Muting Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 3. Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Connecting PRE to a Pro Tools System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Configuring OMS for Your PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Configuring Pro Tools Software for PRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Mic Preamps in Pro Tools Edit and Mix Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Viewing Mic Preamps in Pro Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Mic Preamp Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Mic Preamp Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Changing Settings on One Mic Preamp Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Changing Settings on Multiple PREs (or PRE Channels) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Mic Preamp Remote Control with Digidesign Control Surfaces . . . . . . . . . . . . . . . . . . . . . . . . 28

PRE Guide iv
Appendix A. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Appendix B. Pinout Diagram for the DB-25 Connector . . . . . . . . . . . . . . . . . . . . . . . . . 35
DB-25 Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Appendix C. MIDI Controller Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
PRE MIDI Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 1: Introduction to PRE 1
chapter 1
Introduction to PRE
Welcome to the Digidesign PRE, a multi-pur-
pose microphone preamplifier for Pro Tools sys-
tems. With Pro Tools TDM 5.3.1 (Macintosh),
Pro Tools offers remote control of PRE.
PRE is designed especially for Pro Tools systems,
but it can also be utilized as a stand-alone micro-
phone preamplifier. When used with Pro Tools
TDM 5.3.1 on Macintosh, most PRE features can
be controlled from within the Pro Tools applica-
tion. (In Pro Tools, PREs are referred to as Mic
Preamps). 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 Pro Tools TDM 5.3.1
(Macintosh) software and Digidesign control
surfaces (such as Control|24 and ProControl).
• Maximum fidelity of PRE output signals, by
keeping preamplification of low-level signals
close to the source.
• Analog outputs utilize industry-standard DB-
25 connectors for easy connection to
Pro Tools audio interfaces or any other record-
ing or mixing medium.
• Each channel features:
• Support for microphone (XLR), line level
inputs (1/4˝) and direct instrument (1/4˝)
• Selectable impedance settings for Mic in-
put
• 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)
• Phase invert
• 85 Hz High-Pass Filter
• Up to nine PREs are supported through soft-
ware for up to 72 channels of remote-con-
trolled Mic Preamp channels.
• All features are available in Stand-alone mode,
making PRE ideal for any recording applica-
tion.

PRE Guide 2
What’s Included
• PRE
• AC power cable
• PRE Guide
System Requirements
When used as a stand-alone microphone pream-
plifier, PRE is ready to use.
For remote control within Pro Tools, PRE re-
quires:
• A Pro Tools|HD system (including a Digide-
sign HD-series audio interface)
• Pro Tools TDM 5.3.1 or higher software
• Digidesign-qualified Macintosh computer
• 17˝ or larger color monitor; 1024x768 resolu-
tion
• Digidesign-qualified MIDI interface
Mic Preamps in Pro Tools can optionally be re-
mote-controlled by Digidesign control surfaces
(such as Control|24 and ProControl).
Compatibility Information
Digidesign can only assure compatibility and
provide support for hardware and software it
has tested and approved. For a list of Digidesign-
qualified computers, operating systems, and
third-party devices, refer to the latest compati-
bility information on the Digidesign Web site:
www.digidesign.com
About This Guide
This guide provides a basic overview of PRE fea-
tures and functionality, plus complete installa-
tion instructions for using PRE as a stand-alone
microphone preamplifier, adding PRE to an ex-
isting Pro Tools|HD system, or controlling it by
other means.
For more detailed Pro Tools|HD system installa-
tion instructions, or if you are connecting and
configuring a Pro Tools|HD system for the first
time, see the
Getting Started with HD Guide .
For additional information about using
Pro Tools, see the
Pro Tools Reference Guide .
Conventions Used in This Guide
Digidesign guides use the following conven-
tions to indicate menu choices and key com-
mands:
Convention Action
File > Save Session Choose Save Session
from the File menu
Control+N Hold down the Control
key and press the
N
key
Option-click Hold down the Option key
and click the mouse but-
ton

Chapter 1: Introduction to PRE 3
The following symbols are used to highlight im-
portant information in Digidesign guides:
User Tips are helpful hints for getting the
most from your system.
Important Notices include information that
could affect your data or the performance of
your system.
Shortcuts show you useful keyboard or
mouse shortcuts.
Cross References point to related sections in
other Digidesign guides.

PRE Guide 4

Chapter 2: PRE Hardware Overview and Stand-Alone Operation 5
chapter 2
PRE 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 will default to the last
settings they had at power down, with the ex-
ception 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 Guide 6
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 Pro Tools Periph-
erals dialog (Mic Preamps tab).
PRE can be taken out of Remote Lock-Out mode
by unchecking 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 channel Select switches)
is used in Stand-alone mode when grouping
channels in order to control multiple channels
simultaneously.When lit (green), this LED indi-
cates 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 to single
or multiple inputs of external devices through
the DB-25 output connector on the back panel,
or to any individual input using the 1/4˝ TRS
OSC output. To send the oscillator signal
through a channel on the DB-25 connector,
press OSC, then a channel Insert.
The oscillator is enabled through the front panel
only, and cannot be accessed remotely through
Pro Tools.
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.
Calibration can change with temperature.
The output is nominally +4 dBu, but may
vary up to ± 0.3 dB depending upon the am-
bient temperature inside of PRE. Allow the
unit to heat up and thus stabilize the oscil-
lator output before using the output for cal-
ibration purposes.

Chapter 2: PRE Hardware Overview and Stand-Alone Operation 7
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 con-
trol 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 40).
Peak Meter
These fourteen-segment LEDs indicate input sig-
nal level for any chosen input channel. 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.
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 k
Ω , 15 k Ω , or 1.5 M Ω .
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:
■ 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.
– or –
■ If the input Source is Line, press Input Z to
change to 1.5K or 15K.
– or –
■
If the input Source is Inst (instrument), the In-
put Z cannot be changed from its default 1.5M
setting.

PRE Guide 8
Channel Status Section
Each PRE channel provides switched control for
48V (phantom power), phase reverse, input pad-
ding, access to a unity gain insert send/return,
and a high-pass filter. In addition, all eight
channels have individual Mute switches and sig-
nal 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, the LED is off.
When clipping occurs, the LED will remain lit
(or clear) depending on the Peak Hold setting.
Clips can also be manually cleared with the
Clear Clip switch.
48V Switch and LEDs
This switch applies 48V phantom power to 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 48V back to
the line level device through the XLR cable and
eliminates unnecessary power draw when not in
use for powering microphones.
Dynamic microphones (like a Shure SM57) do
not require 48V to operate, but are not harmed
by it. Most
condenser microphones (like an AKG
C414)
do require 48V to operate. If you are not
sure about the 48V requirements for your micro-
phone, contact the manufacturer, or read your
microphone’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.
Although 48V can be used safely with most
microphones, ribbon microphones can be
damaged by it. Always turn off 48V, and
wait for the red 48V indicator light to go
completely off and any signal to dissipate
before connecting or disconnecting a ribbon
microphone.
Condenser microphones requiring 48V
should not be “hot-plugged” into a PRE Mic
Input where 48V 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.”

Chapter 2: PRE Hardware Overview and Stand-Alone Operation 9
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.
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 for editing. When lit (green), the
Channel Select LED indicates that the channel
can be edited.
The following channel controls can be edited:
• 48V Phantom Power; see “48V Switch and
LEDs” on page 8.
• Phase Reverse; see “Phase Switch and
LEDs” on page 9.
• Pad; see “Pad Switch and LEDs” on page 8.
• Insert; see “Insert Switch and LEDs” on
page 8.
• 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 7.
• Input Gain; see “Gain/Param and Input
Gain” on page 14.
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˝ balanced/un-
balanced 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 re-
spective back panel Line/Inst input.
Use these jacks for convenient access to high im-
pedance instrument inputs.

PRE Guide 10
PRE Back Panel
PRE has the following back panel connectors:
Mic Inputs 1–8
These are balanced XLR jacks, with Pin 1 wired
hot (or “+”), Pin 2 (“–”), and Pin 3 ground.
Use these jacks for microphone connections or
line level devices that support balanced XLR
connectors.
Line/Inst (Line Level/Instrument)
Inputs 1–8
These are balanced 1/4˝ TRS jacks, with Tip
wired hot (or “+”), Ring cold (“–”), and Sleeve
ground.
Unbalanced connections are supported with the
use of standard 1/4˝ mono phone plugs. If using
line inputs with balanced line level devices, be
sure to use balanced to balanced cables to max-
imize 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 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˝ TRS Send and 1/4˝ TRS
Return jacks, with Tip wired hot (or “+”), Ring
cold (“–”), and Sleeve ground. Insert 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.
Output Trims 1–8
The output trims are used to individually cali-
brate each channel’s output and send level.
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

Chapter 2: PRE Hardware Overview and Stand-Alone Operation 11
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 wind 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 sys-
tem).
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 16).
The MIDI Thru connector is not used for
Pro Tools remote control.
Oscillator (OSC) Output
This is a balanced 1/4˝ TRS jack that outputs a
fixed oscillator signal (+4 dBu reference signal at
approximately 1 kHz) for calibrating the inputs
of gear not connected through the DB-25 out-
put. For more information, see “OSC (Oscillator)
Switch and LED” on page 6.
Calibration can change with temperature. The
output is nominally +4 dBu, but may vary up to
± 0.3 dB depending upon the ambient tempera-
ture inside of PRE. Allow the unit to heat up and
thus stabilize the oscillator output before using
the output for calibration purposes.
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.
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 con-
nections.
The Send jacks and the DB-25 connector
both use the output Trim calibration pots
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

PRE Guide 12
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 48V phantom power is disabled. Press
48V, 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.
8 Repeat these steps for additional microphone
connections.
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 (as re-
quired), 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.
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
against sudden spikes and surges, as well as
possible acoustical feedback if a micro-
phone is connected and left “open.”
Although 48V can be used safely with most
microphones, ribbon microphones can be
destroyed by it. You should always turn off
48V, and wait for the red light to go com-
pletely off, before connecting or disconnect-
ing a ribbon microphone.
If using line inputs with balanced line level
devices, be sure to use balanced to balanced
cables to maximize performance.

Chapter 2: PRE Hardware Overview and Stand-Alone Operation 13
Using External Effects Devices
PRE can make dedicated connections to external
analog devices (such as compressors and equal-
izers). 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 chan-
nel.
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 wind the trims all the way up (clock-
wise) to allow for maximum signal output
(+28 dBu) and maximum performance.
Editing 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 14).
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:
1 Press Shift.
2 Press the Select switch of any channels you
want to edit.
When more than one channel is selected, meter-
ing, control states, and Gain/Param settings,
will reflect the activity of the left-most channel
of the group.
Edits made to any member of the group will
now be made to all members, simultaneously.
See “Mixed State Operating Mode While Editing
Multiple Channels” on page 14.
Both the Send and Return jacks are bal-
anced 1/4˝ jacks, with Tip wired hot (or
“+”), Ring cold (“–”), and Sleeve ground.
Insert send levels are post output trim.
To select all channels with one quick stroke,
drag your finger across all the Select
switches.

PRE Guide14
To change a setting with a channel control switch:
1 Select one or more channels to edit, as de-
scribed directly above.
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.)
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 channels are grouped, switch modifica-
tions made to one channel of the group are au-
tomatically applied to all other channels of the
group.
Gain/Param and Input Gain
If an offset exists between grouped channels,
the offset will be maintained while moving the
Gain/Param control until you hit +69 dB gain or
0, at which point the grouped channels will mir-
ror each other.
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 Mute on each channel you want to
mute. To mute additional channels, press their
respective Mute switches. Meters remain active,
and Channel Status controls can still be
changed.
To unmute a channel:
■Press Mute again.
Gain offsets are retained when moved as a
group in Stand-alone mode, but this is cur-
rently not true in Pro Tools Remote mode.
To mute all channels with one quick stroke,
drag your finger across all the Mute
switches.

Chapter 3: Remote Operation 15
chapter 3
Remote Operation
Installation of PRE remote control in Pro Tools
includes:
• Making audio and MIDI connections to PRE.
(See “Connecting PRE to a Pro Tools System”
on page 16.)
• Configuring MIDI. (See “Configuring OMS for
Your PRE” on page 17.)
• Configuring Pro Tools. (See “Configuring
Pro Tools Software for PRE” on page 19.) This
includes:
• Declaring PRE in the Peripherals dialog.
• Mapping PRE outputs to an audio inter-
face’s inputs in the I/O Setup dialog.
Once PRE is configured in Pro Tools, Mic
Preamp controls can be displayed in Pro Tools
Mix and Edit windows, and you can:
• Remote control PRE from the Mix or Edit win-
dow.
– or –
• Use PRE front panel controls to adjust Mic
Preamp controls in Pro Tools.
PRE Remote Control in Pro Tools
The following PRE front panel controls can be
remote-controlled in Pro Tools:
• Input Gain
• Input Source
• Selecting one or more channels for editing
• Input Impedance (Input Z)
• 48V
• Insert
• Pad
• Phase Invert
• High-Pass Filter
The following PRE front panel controls are not
supported by remote control.
• Oscillator on/off
• MIDI channel assignment
• Changing the Peak Hold setting of front panel
Clip LEDs
• Clearing of Clips on the front panel
• Muting individual PRE outputs

PRE Guide16
Connecting PRE to a Pro Tools
System
Audio Connections
PRE must be physically connected to a Digide-
sign audio interface (such as a 192 I/O) in your
Pro Tools system.
To connect your PRE to your Pro Tools system:
■Connect PRE outputs to analog inputs on
your Digidesign audio interface (for example, to
connect PRE to a 192 I/O, use a DB-25 cable to
connect the PRE outputs to the Analog Inputs
on the 192 I/O). For installations with multiple
PREs, repeat the above step.
MIDI Connections
The following are basic instructions for connect-
ing your PRE to a MIDI interface for remote con-
trol.
Before you connect PRE MIDI Ins and Outs, con-
nect and configure your MIDI interface accord-
ing to the manufacturer’s instructions, if you
have not done so already.
To connect a PRE to the MIDI interface:
1 Connect a MIDI cable between the MIDI Out
port on your PRE and the MIDI In port on your
MIDI interface.
2 Connect a MIDI cable between the MIDI In
port on your PRE and the MIDI Out port on your
MIDI interface.
3 For additional PREs, daisy-chain them by con-
necting the MIDI Out port on the first PRE to
the MIDI In port of the second PRE, and so on.
For multiple PRE MIDI cabling considerations,
see “Installations with Multiple PREs” on
page 16.
Setting PRE MIDI Channel
To set global receive/transmit MIDI channel:
1 If you haven’t done so already, connect AC
power to PRE.
2 Power on PRE.
3 On the PRE front panel, press MIDI Chan. The
LED should be lit; if not, press and release again.
The Gain/Param display will display the current
MIDI channel (1–16).
4 Turn the Gain/Param control clockwise to in-
crement MIDI channel numbers, or counter-
clockwise to decrement channel numbers. The
MIDI channel will be set once you stop moving
the control; you do not need to press an Enter
key to set the channel.
5 To exit MIDI Channel mode, press MIDI Chan
again.
6 Repeat the above steps for additional PREs.
Installations with Multiple PREs
To control multiple PREs via a single MIDI port,
set each unit to a unique MIDI channel number.
Keep in mind that if PRE units are set to the
same MIDI channel on a single MIDI port, their
controls will operate in a “linked” fashion—
changing a setting on one unit will change the
setting on all units.
For each PRE output, note the respective au-
dio interface input channels, as these will be
the physical inputs you map PRE outputs to
in Pro Tools. For example, PRE outputs 1–8
attached to a standard 192 I/O map to an-
alog inputs 1–8; however, PRE outputs 1–8
attached to the second A/D card on a
192 I/O represent analog inputs 9–16.