Sound Devices usbpre User manual

User Guide and
Technical Information
v. 1.5 Hardware
Microsoft Windows Driver v. 2.5 with ASIO 2.09
Macintosh OS 9.X Driver v. 2.0 with ASIO 2.09
Sound Devices, LLC
300 Wengel Drive
Reedsburg, WI 53959 USA
Telephone: [phone]
Fax: [phone]
[e-mail]
www.sounddevices.com
®

User Guide and
Technical Information
page 2SOUND DEVICES, LLC
Table of Contents
Product Features . . . . . . . . . . . . . . . . 4
Hardware . . . . . . . . . . . . . . . . . . . . . . 5
Specifications . . . . . . . . . . . . . . . . . 5
System Requirements - Windows . . 6
System Requirements - Mac OS . . . 7
Front Panel - Controls, Indicators . . 8
Bottom Panel - Controls . . . . . . . . . . 9
Side Panels - Connectors . . . . . . . . . 9
Windows OS . . . . . . . . . . . . . . . . . . 10
Installing Hardware . . . . . . . . . . . 10
Driver Software Installation . . . . . 10
Deleting Software Drivers . . . . . . 11
Selecting the USBPre . . . . . . . . . 11
System Tray Icon . . . . . . . . . . . . . 12
Control Panel Application . . . . . . 12
S/PDIF Input and Output . . . . . . . 13
Audio Playback . . . . . . . . . . . . . . . 13
Naming USBPre Hardware . . . . . 13
ASIO (ASIO Installation Only) . . . 14
ASIO Control Panel . . . . . . . . . . . 14
Software Installation . . . . . . . . . . . 15
Macintosh OS Operation . . . . . . . . 15
Connecting Hardware . . . . . . . . . 15
Selecting the USBPre . . . . . . . . . 16
USBPre Mac OS Control Panel . . 16
S/PDIF Input and Output . . . . . . . 18
Mac OS ASIO Installation . . . . . . 19
Recording with the USBPre . . . . . . 20
Input Source Selection . . . . . . . . 20
Input Pad . . . . . . . . . . . . . . . . . . . 20
Sample Rates . . . . . . . . . . . . . . . 20
S/PDIF Inputs . . . . . . . . . . . . . . . 20
Metering . . . . . . . . . . . . . . . . . . . 20
Phantom Power . . . . . . . . . . . . . . 20
Headphone Monitoring . . . . . . . . 20
USB Audio Optimization . . . . . . . . . 21
Memory . . . . . . . . . . . . . . . . . . . . 21
Hard Disk . . . . . . . . . . . . . . . . . . 21
Power Management . . . . . . . . . . . . 21
Notebook Computers (Windows) 21
USBPre Architecture Overview . . . 22
FAQ (Frequently Asked Questions) 23
Approvals . . . . . . . . . . . . . . . . . . . . . 25
Technical Support . . . . . . . . . . . . 25
FCC Statement . . . . . . . . . . . . . . 25
CE Declaration of Conformity . . . 25
Software License . . . . . . . . . . . . . . . 26

User Guide and
Technical Information
page 3SOUND DEVICES, LLC
Welcome!
Copyright Notice
The staff of Sound Devices welcomes you to the USBPre. We have designed the the product to be the
best tool to interface microphones and other analog audio sources with personal computers. The S/PDIF
connectivity of version 1.5 hardware adds even more flexibility. The USBPre includes all the necessary
connections for hard disk recording, streaming, and audio measurement in the studio and field. By com-
bining the best in field production analog audio, high quality digital conversion, the USB protocol, and
robust driver software, the USBPre opens up new possibilities for computer audio.
Applications for the USBPre include:
➾Music Recording
➾Voice-Over Recording
➾Acoustical Test and Measurement
➾Audio for Video
➾Film Sound
➾Live Audio Webcasting
➾High Quality Computer Telephony/Conferencing
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or trans-
mitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, with-
out the written permission of SOUND DEVICES, LLC. The information contained herein is designed only
for use with this USBPre audio interface. SOUND DEVICES is not responsible for any use of this infor-
mation as applied to other audio products.
SOUND DEVICES, LLC shall not be liable to the purchaser of this product or third parties for damages,
losses, costs, or expenses incurred by purchaser or third parties as a result of: accident, misuse, or
abuse of this product or unauthorized modifications, repairs, or alterations to this product, or failure to
strictly comply with SOUND DEVICES, LLC’s operating and installation instructions.
Microsoft, Windows 98, Windows ME, Windows 95, Windows 2000, and Windows XP are registered
trademarks of Microsoft Corporation. Macintosh is a registered trademark of Apple Computer. Other
product and company names mentioned herein may be the trademarks of their respective owners.
“USBPre” and the sound waves logo are registered trademarks of Sound Devices, LLC.

User Guide and
Technical Information
page 4SOUND DEVICES, LLC
Product Features
Simplicity
➾One USB cable provides all power for unit
and carries all audio to and from PC.
➾All controls on front panel - no software-only
features.
➾No sound card needed - no opening the PC
to connect.
Audio Performance
➾Input dynamic range greater than 104 dB (in
24-bit mode).
➾Flat 10 Hz - 20 kHz audio bandwidth.
➾Very low distortion characteristics.
Analog Audio Inputs
➾Active-balanced microphone and line level
inputs.
➾Phantom power (48-volt) for condenser micro-
phones.
➾High-impedance, low-noise DI instrument
inputs.
➾Tape level audio inputs on RCA connectors.
➾Input type is selectable per channel - allowing
two different signal levels simultaneously.
Digital I/O
➾S/PDIF input (coaxial) for direct digital audio
transfers from DAT or other digital medium.
➾S/PDIF output (coaxial) to interface to exter-
nal digital recorders and playback systems.
Level Metering
➾Six-segment, LED peak input meter for pre-
cise level control of analog input sources.
➾Calibrated in dB FS.
Audio Monitoring
➾Mix control enables zero-delay monitoring
of analog source audio, computer audio, or
a mix of both source and computer audio in
headphones.
➾Phono (RCA) jacks connect PC Audio output
to external loudspeakers or preamplifiers.
➾S/PDIF output of PC Audio sources.
USB Powered
➾Bus powering from the USB port eliminates
external power sources or batteries.
➾Regulated internal DC/DC converter for low
noise, consistent audio quality.
Compact, Durable Mechanical
Construction
➾High-strength extruded aluminum chassis.
➾Machined aluminum knobs.
Computer Interface
➾Microsoft Windows 98SE, ME, 2000, and XP
compatible.
➾Mac OS 9X compatible.
➾ASIO 2.0 for Mac OS and Windows.
➾Simple Control Panel application duplicates
front panel buttons.

User Guide and
Technical Information
page 5SOUND DEVICES, LLC
Hardware
Frequency Response: (reference 1 kHz)
10 Hz - 20 kHz, +/- 0.5 dB
(any input to PC recording)
10 Hz - 20 kHz, +/- 1.0 dB
(PC source to PC AUDIO out)
THD+N: (10 Hz - 22 kHz measurement band-
width)
0.05% max. (any input to PC recording, gain
control at min., input driven to -6 dB FS)
0.009% max. (PC AUDIO output, 0 dB FS
output, 100k ohm load)
0.05% max. (HEADPHONES output, 2 V rms
output, 600 ohm load)
E.I.N.: (MIC inputs)
-124 dBu min. (10 Hz - 22 kHz bandwidth,
150 ohm source, gain control at 50% or more,
15 dB pad out)
Clip Level
(1% THD)
Sensitivity
(typical, for 0 dB FS)
min. gain and max. gain
Impedance
(actual)
MIC
(15 dB pad out) -12 dBu (195 mV rms) -10 dBu -53 dBu 2k ohm, active- balanced
MIC
(15 dB pad in) +4 dBu (1.2 V rms) +5 dBu -38 dBu 2k ohm, active- balanced
LINE +24 dBu (12.3 V rms) +24 dBu +7 dBu 65k ohm, active-
balanced
DI +6 dBu (1.5 V rms) + 8dBu -9 dBu 10M ohm,
unbalanced
TAPE +8 dBu (2.0 V rms) +10 dBu -7 dBu 110k ohm,
unbalanced
Output Clipping Levels: (1% THD, Windows
Mixer/Mac volume at max.)
PC AUDIO: +8 dBu (2.0 V rms) w/ 100k ohm
load
HEADPHONES: +11 dBu (2.75 V rms) w/
600 ohm load
Output Impedance:
PC AUDIO: 3.3k ohms
HEADPHONES: 20 ohms
S/PDIF Digital:
24-bit maximum input, 20-bit maximum
hardware output (limited to 16-bit output in
Windows Me and Mac Sound Manager),
sample rate and bit depth selected by record-
ing software and operating system
A/D Converter:
24-bit resolution - no dither added
104 dB min. dynamic range, 24-bit mode
(10 Hz - 22 kHz bandwidth, A-weighted)
96 dB min. dynamic range, 16-bit mode
(10 Hz - 22 kHz bandwidth, A-weighted)
D/A Converter:
16-bit resolution
90 dB min. dynamic range, 24 and 16-bit
mode (10 Hz - 22 kHz bandwidth,
A weighted)
Sample Rates / Bit Depths:
Recording: 8, 16, or 24-bit at 32, 44.1, 48 kHz
Playback: 8, 16-bit at 5 to 55 kHz, will play
back 24-bit sources at 16-bit
Master Clock: (recording)
PLL generated, low jitter
Metering:
Input level at A/D converter
6 segments, 30 dB total range, peak
responding
0 dB on meter = 0 dB FS (0 dB referenced to
Full Scaled Digital)
Phantom Power:
48 V through 6.8k W resistors, each mic input
will supply 10 mA
Specifications
Analog Audio Inputs:

Powering:
USB bus powered, 3 stage soft-start meets
USB hot-plugging power requirements
5 V, 100 mA max current drawn during enu-
meration
5 V, 350 mA quiescent current from USB port
5 V, 500 mA max current from USB port
USBPre requires a full 500 mA USB port. The
USBPre will not be available if connected to a
passive USB connection or hub.
Dimensions (unpackaged):
4.3 cm x 18 cm x 10 cm (H x W x D)
1.7 in. x 7.25 in. x 4.25 in.
Weight:
0.5 kg
1.13 lbs.
Certifications:
Meets FCC Part 15 Class B
Complies with the requirements of European
Directive 89/336/EEC
Included Accessories:
USB Cable
USBPre software installation CD-ROM for
Mac OS and Windows OS
Rubber Feet
User Guide and
Technical Information
page 6SOUND DEVICES, LLC
The USBPre relies on the USB port of a Windows
PC for its interface to the computer. The USBPre
does not function without being connected to a
computer.
The requirements below outline the minimum con-
figurations acceptable for operation with Windows
computer systems and USBPre hardware.
Software applications used with the USBPre have
their own requirements that may be in addition to
the requirements of the USBPre. Consult your soft-
ware application’s documentation.
Operating System:
Windows 98 Second Edition
Windows 2000 SR-1
Windows Me
Windows XP (Home and Professional)
Processor:
Intel Pentium II/300 MHz or Intel Celeron/450
MHz minimum
(Cyrix processors not recommended)
RAM / System Bus Speed:
64 MB (128 MB with most software) / 66
MHz, 100 MHz recommended
Hard Drive:
5400 rpm, 7200 rpm mechanism
recommended
Sound Card:
None required
Audio Software:
Windows compatible audio software with
wave audio support.
Windows compatible audio software with
ASIO audio support.
Motherboard Chipset:
Intel strongly preferred, Via and ALI based
motherboards not recommended
USB Connection:
Full USB 1.1 compliance, single controller,
single hub
For Notebook Computer users:
For proper operation of the USBPre, turn
off all power management when using the
USBPre for audio recording. Power manage-
ment reduces processor speed, system bus
speed, spins down hard disks, shuts down
displays, or a combination of the above to
reduce current consumption and extend bat-
tery run time. The change in state from active
to power-saving mode can disrupt data on the
USB bus and cause unintended dropouts.
Note: Sound Devices cannot guarantee that a
given computer can be used satisfactorily with
the USBPre based exclusively on the fact that
it meets the above requirements.
System Requirements - Windows OS

User Guide and
Technical Information
page 7SOUND DEVICES, LLC
The USBPre relies on the USB port of the Mac for
its interface to the computer. The USBPre will not
function without a USB equipped Mac.
The requirements below outline the minimum con-
figurations for Windows computer systems with
USBPre hardware. Software applications used with
the USBPre have their own requirements that may
be in addition to the requirements of the USBPre.
Consult your software’s documentation.
Operating Systems:
Mac OS 9.0.4 and greater, OS X beta version
available on the web
Processor:
G3/266 or better, native USB port
RAM:
64 MB (128 MB with most software) physical
RAM with virtual memory turned off
System Bus Speed:
66 MHz, 100 MHz recommended
Hard Drive:
5400 rpm recommended, 7200 rpm beneficial
for recommended for multi-track recording
Sound Card:
None required
Audio Software:
Sound Manager compatible audio software.
ASIO-Compatible audio software for use with
ASIO drivers.
For PowerBook and iBook users:
For proper operation of the USBPre, turn
off all power management when using the
USBPre for audio recording. Power manage-
ment reduces processor speed, system bus
speed, spins down hard disks, shuts down
displays, or a combination of the above to
reduce current consumption and extend bat-
tery run time. The change in state from active
to power-saving mode can disrupt data on the
USB bus and cause unintended dropouts.
Note: Sound Devices cannot guarantee that a
given computer can be used satisfactorily with
the USBPre based exclusively on the fact that
it meets the above requirements.
System Requirements - Mac OS

Front Panel - Controls, Indicators
User Guide and
Technical Information
page 8SOUND DEVICES, LLC
1. Input Gain Controls
Adjusts input gain levels. Gain is minimized
(not turned off) at full counter-clockwise set-
ting. Gain control only affects analog input
sources.
2. 48V Phantom Power Switch and LED
Toggles 48-volt phantom power for both
microphone inputs. Phantom is present only
at the XLR microphone inputs. LED illumi-
nates when phantom power is applied.
3. Input Selection Switches
Selects the input connection type. The adja-
cent LED indicates selected input type. For
each input channel (1 or 2), a single input can
be selected - they do not get mixed together.
S/PDIF input is selected for both channels.
4. Input Level Meter
Calibrated in dB FS, the meter shows the
input level of each channel (analog inputs
only).
5. Power LED
Illuminates when USBPre is connected to a
computer and receiving power over the USB
port.
6. MONO Monitoring Switch
Toggles between mono and stereo monitoring
of analog input audio in the headphones only,
especially useful when multi-track recording
and recording from one input. Red LED illu-
minates when MONO is selected. Audio from
the PC is unaffected.
7. Mix Control
Selects the signal source to be monitored
in the headphones between analog source
audio (PRE) and computer audio (PC).
Listening to PRE audio allows zero latency
monitoring of analog recording sources. The
center position mixes monitoring of both
source and computer audio. The signal at the
PC Audio Output is unaffected by this control.
NOTE: S/PDIF digital inputs cannot be moni-
tored in the headphones. S/PDIF signal can
be monitored after being processed by the
computer.
8. Headphone Volume Control
Adjusts overall headphone volume.
12345678

User Guide and
Technical Information
page 9SOUND DEVICES, LLC
Side Panels - Connectors
9. Mic Inputs
Active-balanced XLR inputs accept low-
impedance microphone level signals.
10. Line/DI Inputs
Dual function inputs. Accepts balanced line
level signals when the front panel switch is
in LINE position. Accepts musical instrument
inputs such as guitar pick-ups and electronic
keyboards when the front panel switch is in
DI position. Impedance changes automatically
with front panel Selection Switches.
11. Tape Inputs
Accepts consumer level inputs such as CD,
MiniDisc, DAT, and cassette players via RCA
connectors.
12. Headphone Outputs
3.5 mm and ¼-inch TRS stereo headphone
outputs can drive low-impedance head-
phones. Note: The USBPre can drive
headphones to dangerously loud levels - take
caution when raising the headphone level.
13. PC Audio Output
Audio output to feed powered loudspeakers or
consumer level DAT, MiniDisc, and CD record-
ers. RCA connectors. Computer audio only.
The Volume level from this connection is con-
trolled only by the PC and its software.
14. S/PDIF Input and Output
Coaxial digital input and output connectors.
Input is selected via the front panel input
selection switch. S/PDIF output mirrors the
PC Audio Output signal.
15. USB Port
USB B Type connector, interconnection with
the computer; provides all data and power to
the USBPre via USB bus powering.
Bottom Panel - Controls
16. Microphone Input Pad
15 dB pad for use with “hot” microphone
inputs. Pad can be inserted per channel.
Reduces microphone sensitivity by 15 dB.
91011 12 13 14 15
16

User Guide and
Technical Information
page 10SOUND DEVICES, LLC
Windows OS
Driver Software Installation
Note: Do not connect the USBPre to a com-
puter without first installing the USBPre drivers
and control software.
The included Windows driver software for the
USBPre allows you to select between a “Preferred
Installation” or an “ASIO Installation”. For most
users the Preferred Installation is advised. With it,
the USBPre will act as the audio hardware for all
wave compatible software applications, including
Windows system sounds, Windows Media Player,
DVD players, and most audio recording and play-
back software.
If the ASIO Installation is selected, the USBPre
installs ASIO driver software. ASIO drivers are a
low-level connection to ASIO-compatible audio
applications. With ASIO, a more direct connec-
tion between recording software and the USBPre
is obtained, greatly reducing latency - beneficial
in multi-track music production. Software applica-
tions such as Cubase, Logic, and n-Tracks sup-
port hardware via the ASIO drivers. When ASIO
drivers are installed the USBPre will have limited
functionality with audio applications and system
applications that do not specifically support ASIO.
If you are not certain that you require ASIO driv-
ers, install using the Preferred Installation. You
can only have one type of drivers installed on the
computer at a time. To switch between ASIO and
Preferred audio requires uninstalling and rein-
stalling the driver software.
Preferred Installation
To install the software for the USBPre:
1. Power on your computer and start Microsoft
Windows 98SE, ME, 2000, or XP.
2. Close all open applications.
3 Place the Sound Devices USBPre CD-ROM
in your CD-ROM drive.
4. Run the application D:\setup.exe (where D is
the letter of your CD drive). If you computer
is set to auto launch a CD-ROM, the setup
application will start automatically. Note: The
setup application uses a Windows 2000 ver-
sion of the installer application. You may need
to restart your machine during installation if it
is the first time running this installer applica-
tion in Windows 98SE.
5. Select the Preferred Installation to install the
USBPre for most Windows audio software.
Once the setup program has begun, a series of
on-screen instructions will guide you through the
rest of the installation procedure.
In Windows 2000 and XP, you will be warned that
the USBPre drivers are not digitally signed. Click
“continue anyway” to complete the installation.
Windows ASIO Installation
Follow the same steps as for the Preferred
Installation, but selection ASIO Installation when
prompted.
To verify that the ASIO driver is installed, enter
the Device Manager and view the USB controllers.
When the USBPre is connected to the computer
“USBPre ASIO” will show as the installed device.
(See Windows ASIO.)
Installing Hardware
Once the USBPre drivers have been installed, fol-
low the instructions below to complete the USBPre
hardware installation. These steps will only need to
be performed once. Note: You may need your origi-
nal Windows CD or have the Windows .cab files
loaded on your hard drive to properly install all of
the USBPre hardware drivers.
Select Preferred or ASIO Installation

User Guide and
Technical Information
page 11SOUND DEVICES, LLC
1. Close any open applications.
2. Connect the USBPre hardware directly to the
computer with the included USB cable.
3. The Windows Hardware Wizard activates and
automatically begins searching for drivers for
the USBPre.
4. Depending on your system configuration and
Windows OS, you may be prompted to search
for USBPre drivers. If prompted, define the
path C:\WINDOWS\INF in the “search for”
dialog box of the Hardware Wizard to point
the Wizard to the installed USBPre drivers.
5. The Hardware Wizard will finish, and the
USBPre will be ready to use.
6. Unplug the USBPre hardware, wait a few sec-
onds, and re-connect.
The USBPre is now installed, subsequent instal-
lation procedures are not necessary and the
USBPre can plugged and unplugged when need-
ed.
If you are installing ASIO drivers under Windows
XP, the new hardware wizard will open when
hardware is connected. Follow the dialog boxes to
allows Windows to complete the installation.
Deleting Software Drivers
To remove the USBPre and all of its software com-
ponents from the computer:
1. Disconnect USBPre hardware from the com-
puter.
2. Follow the path Start>Settings>Control
Panel>Add/Remove Programs.
3. Select “USBPre Microphone Interface” from
the list of software applications.
4. Click “Add/Remove..”
5. The wizard will begin. Follow the on-screen
instructions.
6. Restart the computer when prompted to clear
the system registry. USBPre software is now
removed from the system.
To change your system between Preferred installa-
tion (wave audio) and an ASIO installation requires
deleting the software drivers and reinstalling.
Selecting the USBPre
The USBPre communicates with the Windows
operating system and audio software through
Windows USB audio drivers. Software applications
that communicate with Windows wave or direct
sound audio can access the USBPre for record-
ing and playback. The USBPre functions as a very
powerful outboard sound card and replaces the
on-board sound cards functionality.
With most computer systems the USBPre
becomes the default audio input and output device
upon connection to the computer. Depending on
your system’s configuration, it may be required
to manually select the connected USBPre as the
addressed audio device:
Follow the path Start>Settings>Control
Panel>Multimedia. (In Windows ME and Windows
2000, select path Start>Settings>Control
Panel>Sounds & Multimedia.
1. In Multimedia Properties, select the Audio tab.
2. Pull down the menu for Playback devices and
select the USBPre Interface (it may be named
differently if renamed).
3. Pull down the menu for Recording devices
and select the USBPre Interface (it may be
named differently if renamed).
Note: Do not plug or unplug the USBPre when
actively recording or playing audio. The application
and the operating system may become unstable.
Unplug the USBPre only after exiting out of audio
application software.
To test whether the USBPre is properly recording,
perform the following test:
1. Connect the USBPre to the computer.
2. Select the USBPre as the preferred device
(see Selecting the USBPre)
3. Connect an audio source to an input of
USBPre and select its input type via the front
panel input selection buttons.
4. Verify that the front panel level meters are
responding to the audio.
5. Launch the Windows Sound Recorder appli-
cation from Start >Programs >Accessories
>Entertainment >Sound Recorder.
6. Select File>Convert Now, and select 44.1/16
bit attributes.
7. Record audio.
8. Play back the audio to verify that it has
recorded.

User Guide and
Technical Information
page 12SOUND DEVICES, LLC
Control Panel Application
The Windows control panel application duplicates the selections of the front panel of the USBPre hard-
ware. The control panel also allows naming individual USBPre’s for identification. When two USBPre
devices are connected to the computer the control panel can select between the two units. To launch the
application follow Start> Applications> Sound Devices USBPre> USBPre.
1. Input Selection
Selects the input type of each channel. If a
S/PDIF version of USBPre is connected, S/
PDIF shows up as an available input type.
2. Phantom Power
Applies 48-volt phantom power to both micro-
phone inputs.
3. Button Lock
When selected, button lock prevents the func-
tion selection on the USBPre hardware from
being active, preventing unintended changes
to the function.
4. Device Selection
Shows the name of the attached USBPre.
From the factory the USBPre is named
“USBPre Microphone Interface”. The name in
the Device Selection field can be highlighted
and the hardware can be renamed. This
name will be applied to the hardware and
will show up in the Device Selection field in
software applications that can select between
audio hardware.
5. Headphone Monitor
Selects between mono and stereo headphone
monitoring of analog audio sources.
6. S/PDIF Output Sync
When a frequency is selected, the S/PDIF
ouput clock remains active at the selected fre-
quency in the absence of audio.
7. About
Indicates the revision of the USBPre driver
software.
8. Help
Launches the help file.
System Tray Icon
When the USBPre Control Panel application is
active a system tray icon shows the status of the
USBPre. Under Windows 2000 and XP the appli-
cation will launch automatically when USBPre
hardware is connected to the computer, however,
the control panel will be hidden. To open the con-
trol panel with connected hardware, double-click
on the USBPre icon in the system tray. When the
USBPre is properly connected to the computer the
icon illuminates green.
When the USBPre is disconnected from the com-
puter, the system icon changes from green to red.
The application is still open, however, there is no
hardware to control.
USBPre is activated. USBPre is deactivated.
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User Guide and
Technical Information
page 13SOUND DEVICES, LLC
Naming USBPre Hardware
Audio Playback
A user-defined name can be associated with each
USBPre. This name appears in audio application
software - typically in the device selection menu.
From the factory the default name is “USBPre
Microphone Interface”. This name is written to
non-volatile memory inside the USBPre, and will
appear whenever the USBPre is connected.
To change the default name:
1. Connect the USBPre to the computer.
2. Open the Control Panel application.
3. Highlight the name in the Device Selection
area.
4. Enter a new name and hit “enter”. Follow the
on-screen instruction.
5. Disconnect the USBPre, then reconnect. The
name will be written to the USBPre firmware.
Renaming the USBPre
When connected to a computer the USBPre
becomes the preferred audio hardware. To test
whether the USBPre is properly playing audio, per-
form the following test:
1. Connect the USBPre to the computer.
2. Select the USBPre as the preferred device
(see Selecting the USBPre in Windows)
3. Connect headphones or powered loudspeak-
ers to the output of the USBPre.
4. Double-click on the file Play Me.wav on the
Sound Devices installation CD. This is a 16-bit
/ 44.1 kHz wave file.
5. Listen to verify that audio is playing through
the USBPre.
The USBPre can be used to transfer digital audio
into and out of a computer via coaxial S/PDIF.
Input
The USBPre can accept S/PDIF input sources
at 16, 20, and 24-bit and with sample rates of
32, 44.1, and 48 kHz. With Windows 98SE and
Windows 2000 a full 24-bit signal will be trans-
ferred. In Windows Me signals with bit depths high-
er than 16-bit will be truncated to 16-bit. The input
selection LED flashes without S/PDIF connection
and turns solid when a valid S/PDIF source is con-
nected.
Output
In Windows 98SE and 2000 the output of the
USBPre is limited to 16-bit with wave audio (using
the ASIO drivers enables a maximum output of
20 bits via S/PDIF). A 20 or 24-bit signal sent to
the USBPre will output 16-bit data via the analog
output.
To improve the transfer of digital audio, the
USBPre Control Panel has an S/PDIF output sync
selection. With no sync selected devices con-
nected to the USBPre’s S/PDIF output may take
several seconds to “lock-up” to the S/PDIF signal.
During lock-up, objectionable audible artifacts are
present. When no audio is present the S/PDIF out-
put is inactive. When an output sync sample rate
is selected in the Control Panel the S/PDIF output
port is always active, sending 0’s at the selected
sample rate when no audio is present. This greatly
improves the performance of transfers from the
S/PDIF output, since a lengthy pre-roll is not
required to lock-up the data.
NOTE: Selecting an output sync sample rate in the con-
trol panel may have a negative on audio performance
since all audio, regardless of its native sample rate, will
output at the selected sync rate. Sample rate conver-
sion will occur in Windows when the computer receives
an audio signal at a frequency that is different from the
selected sync sample rate. Again, make certain that the
selected output sync sample rate matches the sample
rate of the files being played, otherwise sample rate con-
version will occur.
S/PDIF Input and Output

ASIO Control Panel
User Guide and
Technical Information
page 14SOUND DEVICES, LLC
ASIO (ASIO Installation Only)
1. Device
Shows the device that is under control -
USBPre Microphone Interface.
2. Channels
Shows for which input channels the settings
apply.
3. Input Sample Rate
This is the rate at which the USBPre will sam-
ple the incoming audio signal. The USBPre
supports 32 kHz, 44.1 kHz, and 48 kHz.
4. Output Resolution
This is the resolution of the output bit stream.
The USBPre can support either 16 bit or 20
bit output. Note: If the recording resolution
and the output resolution do not match a
warning message will appear in the Devices
window. See the use dithering note for the
reason why.
5. Recording Resolution
This is the size of each sample taken from the
input stream. The USBPre can support 16 bit,
or 24 bit. Note: The option for 32 bit recording
does not result in 32 bit resolution out of the
USBPre.
6. Use Dithering
The use of dithering will improve the conver-
sion to a lower bit depth on both the output
and the input. Enable the “use dithering”
check box in two situations. 1) The ASIO
recording resolution is set higher than the
application recording resolution. 2) The appli-
cation output resolution is higher than the
ASIO output resolution.
7. System Performance
This controls the speed at which the recorded
signal is set. The ASIO control panel supports
Highspeed, Fast, Normal, and Relaxed. If you
system has noticible clicks decrease the sys-
tem performance.
The ASIO control panel allows selecting vari-
ous functions for the USBPre. The Control Panel
allows control of the USBPre input sample rate,
input recording resolution, and output resolution.
This panel can be launched from within an audio
application’s audio setup window.
When ASIO is the installed driver type, the
USBPre will show as an ASIO device in the ASIO
control panel of supported software. To verify that
the ASIO driver is installed open the USBPre con-
trol panel application as view About. The installa-
tion type will be shown.
Under ASIO the USBPre is still available as
audio hardware to Windows audio applications,
but the Preferred installation is recommended for
use when ASIO is not required. The USBPre will
appear as USB Audio Device in the multimedia
panel when the USBPre ASIO driver is installed.
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User Guide and
Technical Information
page 15SOUND DEVICES, LLC
Note: The USBPre software must be installed
onto the computer in order to communicate
with the USBPre. Install the software before
plugging in the USBPre for the first time.
Follow these simple installation and instructions
and you will be ready to connect audio sources
in minutes. The included CD-ROM installs the
USBPre Control Panel Application and required
extension software on to your computer.
1. Power on your computer and navigate to the
desktop.
2. Close any open applications.
3. Place the Sound Devices USBPre CD-ROM
in your CD-ROM drive.
4. Launch USBPre Installer from the CD-ROM,
or launch the installer application downloaded
from the support website.
5. Once the installation program has begun fol-
low the on-screen instructions in the installer
application. Be certain to review the READ
ME file for late breaking information regarding
the USBPre.
Connecting Hardware
Make certain to quit any open audio applications
before connecting the USBPre. If not, the USBPre
will not be available for use as audio I/O. There is
no on or off switch on the USBPre. Plugging and
unplugging the USBPre is its equivalent.
When the hardware is connected, the input selec-
tion LEDs will scroll, showing that the USBPre is
connecting with its driver software.
If the LEDs do not scroll when the USBPre is
connected, the driver software is not properly
installed.
To verify that the USBPre is connected, open the
USBPre control panel and notice that changes
made to the USBPre’s settings are reflected in the
control panel.
The USBPre is now connected, subsequent instal-
lation procedures are not necessary and the
USBPre can be plugged and unplugged when
needed.
Deleting USBPre Software
To remove the USBPre and all of its software com-
ponents from the computer:
1. Disconnect USBPre hardware from the com-
puter.
2. Run the USBPre Installer application and
select “Uninstall”.
3. Restart the computer. USBPre software is
now completely removed from the system.
Macintosh OS Operation
Software Installation

User Guide and
Technical Information
page 16SOUND DEVICES, LLC
The USBPre communicates with the Mac OS and
audio software through a USB Sound Manager
driver. Software applications that communicate
with Sound Manager can communicate with the
USBPre for recording and playback.
Depending on the applications software, you may
need to select the USBPre in the Sound control
panel before launching audio software in order for
it to be used as audio input and output hardware.
Note: Do not plug or unplug the USBPre when
actively recording or playing through the USBPre.
The application and the operating system may
become unstable. Unplug the USBPre only after
exiting out of audio application software.
Audio Playback
Depending on the configuration file loaded (see
below), the USBPre may show up as built-in audio
or as a separate USB audio output device When
connected to the computer the USBPre can take
over playback of audio, disabling internal audio
1. Input Selection
Selects the input type of each channel. If a
S/PDIF version of USBPre is connected, S/
PDIF shows up as an available input type.
2. Phantom Power
Applies 48-volt phantom power to both micro-
phone inputs.
3. Headphone Monitor
Selects between mono and stereo headphone
monitoring of analog audio sources. PC audio
remains in stereo.
4. Device Information
Shows the name of the attached USBPre,
the sample rates under Sound Manager,
and whether it is in Sound Manager or ASIO
mode.
5. Record Sample Rate
Indicates the selected record sample rate.
See “Configure the USBPre” to change record
sample rates.
6. S/PDIF Playback Sample Rate
If an S/PDIF unit is connected, the control
panel will indicate the sample rate of S/PDIF
audio played out of the S/PDIF connection.
7. Help
Launches the HTML-based help file.
8. Button Lock
When selected, button lock prevents the func-
tion selection on the USBPre hardware from
being active, preventing unintended changes
to the function.
9. Configure Button
When in the configuration mode, this allows
record sample rates to be changed in Sound
Manager (see Configuration Mode).
USBPre Mac OS Control Panel
The USBPre control panel application duplicates
the selections of the front panel of the USBPre
hardware. The control panel also serves as the
utility to load configuration files onto the USBPre.
Configuration files are required to change record
sample rates. The USBPre control panel is
installed into the Control Panels folder of the
System Folder.
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Selecting the USBPre

User Guide and
Technical Information
page 17SOUND DEVICES, LLC
The USBPre ships from the factory with a record
sample rate of 44.1 kHz. To change record sample
rates, you must to install a new configuration file
into the USBPre firmware. To enter the configura-
tion mode:
1. Unplug any USBPre hardware from the com-
puter.
2. Launch the USBPre control panel.
3. Hold down any front panel button while plug-
ging in the hardware.
This will bring up the following dialog box:
After hitting OK the USBPre control panel will
open again with the Configure button available.
Select Configure. A list of possible configuration
settings is available in the Configurations folder in
the Sound Devices USBPre folder. Select from the
following:
Configurations
There are three variables to the USBPre’s
Macintosh configuration files. The syntax of the file
names is as follows:
Input Types
There are two different input types, Mic In and
Sound In. Both types function identically in most
applications. The difference is the selection in the
Sound Manager Input Sound Manager Output
playback. To return to built-in audio playback,
unplug the USBPre (do not unplug the USBPre
while playing or recording audio). The USBPre will
play back 8 or 16-bit audio files with sample rates
from 5 kHz to 48 kHz. Because of the way Sound
Manager functions playback sample rate may
always be at 44.1 kHz.
Configuring the USBPre
Input Type_Output Type_Record Sample

User Guide and
Technical Information
page 18SOUND DEVICES, LLC
The USBPre can be used to transfer digital audio
into and out of a computer via its S/PDIF connec-
tions. Please read the following notes relating to
S/PDIF in Mac OS.
Input
The USBPre can accept S/PDIF input sources at
16, 20, and 24-bit and with sample rates of 32,
44.1, and 48 kHz. The input selection LED flashes
without S/PDIF connection and turns solid when a
valid S/PDIF source is connected. Mac OS Sound
Manager will truncate data higher than 16-bit to
16-bit.
Be certain to match the sample rate of the S/PDIF
input with the corresponding configuration file of
the same sample rate, otherwise objectionable
distortion will be present. For instance, select a 48
kHz sample rate configuration file (see Configuring
the USBPre) when accepting a 48 kHz S/PDIF signal.
Output
Macintosh Sound Manager is limited to a maxi-
mum of 16-bit output. Any audio file greater than
16-bit will be truncated to 16-bit.
The Macintosh Sound Manager continuously out-
puts S/PDIF clock data at 44.1 kHz, even when no
audio is present. Therefore, all audio played back
through the USBPre S/PDIF output is at 44.1 kHz.
This means that audio files different than 44.1 kHz
go through a sample rate conversion in the operat-
ing system before being sent to the USBPre. For
many applications, this is acceptable, however,
you may want to change this output sample rate to
transfer 32 kHz or 48 kHz files at their respective
rates.
Sound Control Panel, where the USB audio device
(USBPre) will show up as either a Mic source
or a Sound In source. The one advantage of a
Sound In configuration type is that the selection
“Play Through Hardware” is available in the Sound
Manager Control Panel. Playing through hardware
is not available with Mic In types.
Output Types
Two different output types, Speaker and Line are
available. With the Line configuration type the
USBPre shows up in the audio output selection
of the Sound Control Panel as a separate USB
audio output device. Because it is seen as sepa-
rate hardware, it can be selected as required.
With the Speaker output types, the USBPre is not
seen in the Sound Control Panel as a selection
- it becomes the “built-in” audio device, and sim-
ply takes over all playback audio functions of the
Macintosh. To revert to internal speakers, unplug
the USBPre with the Speaker type.
Record Sample Rate Selection
Three possible record sample rates are available,
32 kHz, 44.1 kHz, and 48 kHz. When using the
S/PDIF input on the USBPre it is very important
to select a Record Sample Rate that matches the
source material, otherwise objectionable audio will
occur.
After selecting a configuration you will receive this
dialog box:
Disregard this message and hit OK. If you suc-
cessfully configured the box you will see:
Click OK, unplug the USBPre, wait a few seconds,
and reconnect. Verify the new sample rate in the
USBPre control panel.
S/PDIF Input and Output

User Guide and
Technical Information
page 19SOUND DEVICES, LLC
Mac OS ASIO Installation
The USBPre is installed as a Sound Manager
audio device as its default. To enable the
ASIO driver several steps are required.
1. In Extension Manager, enable the extension
named “PGUSBPre”.
Note, you DO NOT NEED TO RESTART the
computer after changing the state of the
PGUSBPre extension. Simply unplug and plug
the USBPre to enable the extension.
2. Copy (do not move) the USBPre ASIO file to
the ASIO Driver folder of the audio software
applications.
The USBPre is now available as an ASIO device
for ASIO compatible software. Verify that the
USBPre is an ASIO device by opening the USBPre
control panel.
When the USBPre is enabled as an ASIO device,
the USBPre does not show up in Sound Manager.
The USBPre can be either an ASIO device or a
Sound Manager device under Mac OS, both not
both at once.
In audio software, open the devices selection to
ajust the ASIO control panel (see ASIO Control
Panel)
Extensions Manager
Control Panel - USBPre as ASIO
Copy the USBPre ASIO file
USBPre Selected in Digital Performer

User Guide and
Technical Information
page 20SOUND DEVICES, LLC
Input Source Selection
USBPre has two input channels. Depending on the
recording software used, the inputs can be defined
as a single, stereo input or as two separate mono
inputs. Each analog input on the USBPre can be
set to different input types. Since S/PDIF is a two-
channel digital protocol, both channels are S/PDIF
when selected.
Input Pad
With some combinations of microphone sensitivity
and sound pressure levels, the microphone input
of the USBPre can become overloaded. The bot-
tom-side panel input pad inserts a 15 dB pad to
scale the input gain range for high microphone
input levels. This pad is selected per channel. The
pad affects only the microphone inputs.
Sample Rates
In Windows OS, software applications control the
sample rate and bit depth of the analog inputs of
the USBPre. Valid sample rates for recording with
the USBPre are 32 kHz, 44.1 kHz, and 48 kHz.
Valid bit depths for recording with the USBPre are
8, 16, and 24 and 32-bits (32-bit is really the same
as 24-bit to the operating system). Recording soft-
ware applications may show other “valid” sample
rates for the USBPre. These should not be used,
as the operating system performs a “sample rate
conversion” while recording. Sample rate conver-
sion is very CPU-intensive and can cause choppy
audio and/or crashes. In Mac OS, the sample rate
is selected by loading a configuration file onto the
USBPre (see Selecting Sample Rates for Mac
OS). When using S/PDIF inputs sources in both
Windows and Mac OS, the sample rate selected in
software must match the sample rate that is at the
S/PDIF input or digital distortion will be heard.
Any sample rate from 5 to 55 kHz can be played
back on the USBPre at 8 or 16-bit.
S/PDIF Inputs
The coaxial S/PDIF input on the USBPre accepts
digital input sources with bit depths of 16, 20, and
24-bit, and sample rates of 32, 44.1, and 48 kHz.
When S/PDIF input is selected on the hardware,
the front panel selection LED will flash until it
receives a valid digital signal. Note: in Windows
Me and Mac OS without ASIO any source with bit
depths greater than 16-bit will be truncated to 16-
bit.
In Windows the sample rate of the source mate-
rial into the S/PDIF input must match the sample
rate selected in recording software, otherwise a
rate mismatch will occur and distortion will cause
an unusable signal. In Mac OS the sample rate
of source material must match the sample rate
selected in the configuration file, otherwise a rate
mismatch will occur. See S/PDIF in the individual
operating systems sections for more information.
It is not possible to directly listen to S/PDIF input
signals via the USBPre since the USBPre has its
digital-to-analog converter connected to the PC
audio output. S/PDIF signals can be monitored
after recording or streaming via the PC Audio
outputs. However, depending on the recording soft-
ware used, you may be able to route an S/PDIF
input to an output for “real-time” monitoring.
Metering
The input meter on the USBPre is calibrated in
peak responding dB FS. If recording software does
not have its own level metering, metering from the
USBPre is necessary. When the red peak LED illu-
minates, the signal is very near clipping. Reduce
the input gain control to avoid overloading the
inputs. The front panel meter reads signals from
the analog inputs only. If S/PDIF is selected as an
input sources the meters will not activate.
Phantom Power
USBPre provides phantom power for condenser
microphones. When selected, 48-volt phantom
power is applied to both inputs. Condenser micro-
phones that can operate on phantom voltages
from 11-52 volts will function properly with 48-volt
phantom.
Dynamic microphones typically do not require
phantom power. A properly connected balanced,
dynamic microphone is not affected by the pres-
ence of phantom power nor will it draw any cur-
rent. However, it is good practice to turn phantom
power off when not needed. Poor or incorrectly
wired microphone cable can cause audible arti-
facts in microphone signals. Some wireless receiv-
ers outputs are adversely affected by the presence
of phantom power, therefore, consult the wireless
receiver documentation.
Headphone Monitoring
USBPre has a high current headphone amplifier
that can monitor analog input audio, computer
Recording with the USBPre