Universal Audio 4-710d User manual

Model 4-710d
Four-Channel Tone-Blending
Mic Preamplifier
Universal Audio Part Number 65-00051
Revision A
Universal Audio, Inc.
Customer Service & Tech Support: +1-877-MY-UAUDIO
Business, Sales & Marketing: +1-866-UAD-1176
www.uaudio.com

ii
Notices
This manual provides general information, preparation for use, installation and operating instructions
for the Universal Audio Model 4-710d.
Disclaimer
The information contained in this manual is subject to change without notice. Universal Audio, Inc.
makes no warranties of any kind with regard to this manual, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose. Universal Audio, Inc. shall not be
liable for errors contained herein or direct, indirect, special, incidental, or consequential damages in
connection with the furnishing, performance, or use of this material.
Copyright
© 2011 Universal Audio, Inc. All rights reserved.
This manual and any associated software, artwork, product designs, and design concepts are subject
to copyright protection. No part of this document may be reproduced, in any form, without prior written
permission of Universal Audio, Inc.
Trademarks
4-710d, 710, Twin-Finity, 4110, 8110, SOLO/110, SOLO/610, 2-610, LA-610, LA-2A, 2-LA2, LA-3A,
6176, 1176LN, 2-1176, 2192, DCS Remote Preamp, UAD and the Universal Audio, Inc. logo are
trademarks of Universal Audio, Inc. Other company and product names mentioned herein are
trademarks of their respective companies
FCC Compliance
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) the device must accept any
interference received, including interference that may cause undesired operation.
Contents of This Box
This package should contain:
•(1) Universal Audio 4-710d unit
•(1) Set of 4 rack mounting screws with washers
•(1) User Manual
•(1) Tip In Sheet
•(1) IEC power cable
•(1) Warranty Registration Card
•(1) UA full line catalog

Notices
iii
Important Safety Information
Before using this unit, be sure to carefully read the applicable items of these operating instructions and the
safety suggestions. Afterwards, keep them handy for future reference. Take special care to follow the warnings
indicated on the unit, as well as in the operating instructions.
1. Water and Moisture - Do not use the unit near any source of water or in excessively moist environments.
2. Object and Liquid Entry - Care should be taken so that objects do not fall, and liquids are not spilled, into
the enclosure through openings.
3. Ventilation - When installing the unit in a rack or any other location, be sure there is adequate ventilation.
Improper ventilation will cause overheating, and can damage the unit.
4. Heat - The unit should be situated away from heat sources, or other equipment that produce heat.
5. Power Sources - The unit should be connected to a power supply only of the type described in the
operating instructions, or as marked on the unit.
6. Power Cord Protection - AC power supply cords should be routed so that they are not likely to be walked
on or pinched by items placed upon or against them. Pay particular attention to cords at plugs,
convenience receptacles, and the point where they exit from the unit. Never take hold of the plug or cord
if your hand is wet. Always grasp the plug body when connecting or disconnecting it.
7. Grounding of the Plug - This unit is equipped with a 3-wire grounding type plug, a plug having a third
(grounding) pin. This plug will only fit into a grounding-type power outlet. This is a safety feature. If you
are unable to insert the plug into the outlet, contact your electrician to replace your obsolete outlet. Do
not defeat the purpose of the grounding-type plug.
8. Cleaning - Follow these general rules when cleaning the outside of your 4-710d:
a. Turn the power Off and unplug the unit
b. Gently wipe with a clean lint-free cloth
c. If necessary, moisten the cloth using lukewarm or distilled water, making sure not to oversaturate it
as liquid could drip inside the case and cause damage to your 4-710d
d. Use a dry lint-free cloth to remove any remaining moisture
e. Do not use aerosol sprays, solvents, or abrasives
9. Nonuse Periods - The AC power supply cord of the unit should be unplugged from the AC outlet when left
unused for a long period of time.
10. Damage Requiring Service - The unit should be serviced by a qualified service personnel when:
a. The AC power supply cord or the plug has been damaged; or
b. Objects have fallen or liquid has been spilled into the unit; or
c. The unit has been exposed to rain; or
d. The unit does not operate normally or exhibits a marked change in performance; or
e. The unit has been dropped, or the enclosure damaged.
11. Servicing - The user should not attempt to service the unit beyond that described in the operating
instructions. All other servicing should be referred to qualified service personnel.

Table Of Contents
iv
Notices ................................................................................................................................................... ii!
Introduction............................................................................................................................................ 5!
A Letter from Bill Putnam Jr..............................................................................................................................5!
Overview ...........................................................................................................................................................6!
Features............................................................................................................................................................6!
The Two Page, Two Minute Guide to Getting Started............................................................................... 7!
Front Panel Descriptions......................................................................................................................... 9!
Analog Controls ................................................................................................................................................9!
Digital Controls...............................................................................................................................................12!
Rear Panel Descriptions ....................................................................................................................... 14!
Digital Connectors ..........................................................................................................................................14!
Analog Connectors..........................................................................................................................................15!
Interconnection Diagrams .................................................................................................................... 17!
Analog-Only Setup ..........................................................................................................................................17!
Basic Digital Setup.........................................................................................................................................18!
Advanced Digital Setup ..................................................................................................................................19!
Model 4-710d Overview ........................................................................................................................ 20!
Digital Clocking Primer......................................................................................................................... 23!
Insider’s Secrets................................................................................................................................... 25!
History of the Model 4-710d ................................................................................................................. 27!
Glossary of Terms ................................................................................................................................. 29!
Maintenance......................................................................................................................................... 34!
Calibration......................................................................................................................................................34!
Fuse................................................................................................................................................................34!
Voltage Select.................................................................................................................................................34!
Service............................................................................................................................................................34!
AES/EBU DB-25 Connector Pinouts.................................................................................................................34!
Session Recall Sheet ............................................................................................................................ 35!
Block Diagram...................................................................................................................................... 36!
Specifications....................................................................................................................................... 37!
Analog Section, Channels 1–4........................................................................................................................37!
Analog-To-Digital Converter Section...............................................................................................................39!
Digital Output Section ....................................................................................................................................40!
Connector Types..............................................................................................................................................40!
Mechanical and Power....................................................................................................................................40!
Index..................................................................................................................................................... 41!
Additional Resources............................................................................................................................ 43!
Universal Audio Website .................................................................................................................................43!
Product Registration.......................................................................................................................................43!
Warranty .........................................................................................................................................................43!
Service & Support ...........................................................................................................................................43!

5
Introduction
A Letter from Bill Putnam Jr.
Thank you for purchasing the Model 4-710d Four-Channel Tone Blending Mic Preamplifer — Universal
Audio's new analog+digital hybrid product. The 4-710d combines four channels of our Model 710
Twin-Finity™ preamplifier with eight channels of pristine analog-to-digital conversion and adds a
complement of modern convenience features, all in a 2U, all-metal chassis at an amazing price.
Our all-original 710 Twin-Finity preamp with Tone Blending has proved to be wildly popular among
engineers, producers, and artists seeking a broad palette of sounds from clean to warm in a single,
affordable unit. The innovative preamp design of the Model 710 combines both the classic retro
warmth of UA tube design and the transient bite of solid-state. The 710 was created specifically to
add the tonal versatility and sonic inspiration missing from generic audio interface preamps. The key
to its sonic flexibility lies in its innovative circuit design, featuring a solid-state transimpedance input
amp simultaneously driving separate, phase-aligned tube and solid-state gain stages, which are then
summed to a single output. The mix between the single-ended class-A triode tube stage and solid-
state transimpedance stage is controlled via a unique “Blend” knob. Blending is continually variable
between 100% tube and 100% solid-state offering a practically infinite range of unique preamp tones
and the ability to easily dial in your own signature sound.
With the 4-710d, we've added even more value to the 710 mic preamps. Each channel includes an
1176-style compressor; this dynamics circuit sounds incredible and provides yet another dimension of
available sounds. For flexible signal routing and external processing, the 4-710d also includes
send/return jacks in each preamp that can be individually switched via the front panel.
The 4-710d facilitates easy integration of analog signals into your digital world with its built-in high
quality 8-channel A/D converter. Selectable sample rates from 44.1 to 192 kHz, digital output via ADAT
optical or AES/EBU via industry-standard DB-25 connector, and flexible low-jitter clocking options
make it easier than ever to get mic, line, or instrument signals directly into your DAW with a minimum
of hardware and fuss. The A/D converters include LED metering, and an 8-channel soft limiter helps
prevent digital overs.
Most of us at Universal Audio are musicians and/or recording engineers. We love the recording process,
and we really get inspired when tracks are beautifully recorded. Our design goal for the
4-710d was to build a hybrid mic preamp and A/D converter that we would be delighted to use
ourselves—one that would induce that “a-ha” feeling you get when hearing music recorded in its
most natural, inspired form.
Developing the Model 4-710d – as well as Universal Audio’s entire line of quality audio products
designed to meet the needs of the modern recording studio while retaining the character of classic
vintage equipment – has been a very special experience for me and for all who have been involved.
While, on the surface, the rebuilding of UA has been a business endeavor, it's really been so much
more than that: in equal parts a sentimental and technical adventure.
We thank you, and we thank my father, Bill Putnam.
Sincerely,
Bill Putnam Jr.

Introduction
6
Overview
The Universal Audio 4-710d is a four-channel microphone/line preamplifier with tube and solid-state
tone blending, offering four additional line inputs, dynamics control, and eight channels of pristine
analog-to-digital conversion. The 4-710d combines UA’s classic design approach with several modern
innovations, creating a unique studio device suited to a wide range of applications.
At the core of the 4-710d are four channels of tone-blending “Twin-Finity” mic preamps with true-
bypass 1176-style compression. Each of the four mic preamp channels allows for continuously
variable phase-aligned tone between 100% tube and 100% solid-state. Send and return jacks are
available for external processing or signal access.
The eight analog inputs are digitized via high-quality 24-bit A/D converters at selectable sample rates
up to 192 kHz. Digital output is available via dual ADAT “lightpipe” or AES/EBU DB-25 connectors,
facilitating integration with most popular audio interfaces.
Features
Preamplifiers
•Four TEC Award-winning 710 Twin-Finity™ microphone/line preamps, each featuring:
•Dual-path 285-volt Class-A tube and transimpedance solid-state preamps
•Phase-aligned tone-blending of tube and solid state circuits, creamy to crunchy
•Newly designed 1176-style compression circuit per preamp channel
•JFET Direct Input with 2.2MΩultra Hi-Z impedance w/auto input override
•Large backlit VU meters for flexible metering of input drive, gain level, and gain reduction
•Balanced send/return inserts (half-normalled)
•48V phantom power
•75 Hz low cut filter
•Polarity switch
•Monolithic balanced output stage
Analog-to-Digital Conversion
•Eight channels of high quality 24-bit A/D conversion:
•Selectable sample rates up to 192 kHz
•Digital output via dual ADAT optical and AES/EBU DB-25 connectors
•8-channel soft limiter (switchable for all channels)
•Ultra-low jitter clock subsystem
•LED metering array with clip/hold indicators
•75ΩBNC work clock I/O
•Digital outputs anti-pop protection on power-up
Other
•Universal voltage internal power supply
•Heavy-duty metal construction, two-space rack unit
•One year warranty including parts and labor

7
The Two Page, Two Minute Guide to Getting Started
No one likes to read owner’s manuals. We know that.
We also know that you know what you’re doing—why else would you have bought our product?
So we’re going to try to make this as easy on you as possible. Hence this two-page spread, which we
estimate will take you approximately two minutes to read. It will tell you everything you need to know to
get your Universal Audio 4-710d up and running, without bogging you down with details.
Of course, even the most expert of us has to crack a manual every once in awhile. As the saying goes,
“as a last resort, read the instructions.” You’ll find those details you’re craving—a full description of
all front and rear panel controls, interconnection diagrams, insider’s secrets, history, theory,
maintenance information, block diagrams, specifications, even a glossary of terms—in the pages that
follow.
Getting Started With Your 4-710d:
Step 1: Place the 4-710d where you intend to use it. Chassis mounting hardware is provided, allowing
the 4-710d to be used in a standard 19" rack (taking just two spaces), and so we recommend that the
4-710d be securely mounted in a rack if possible.
Step 2: Mute your monitors and then, using a balanced cable with XLR connectors, connect the 4-
710d’s rear panel line output(s) to the appropriate input(s) on your patch bay, mixer, or DAW.
Step 3: Set the front panel +48V (phantom power), 15dB PAD, and LOW CUT switches to their down
(OFF) position.
Step 4: Set the front panel POLARITY switch to its down (IN ø) position.
Step 5: Connect the desired input source to one of the 4-710d’s rear panel balanced XLR mic and/or
line inputs (page 15). Alternatively, an electric guitar or bass can be connected to a front panel
unbalanced 1/4" Hi-Z input (page 9); however, note that the 4-710d’s jack sensing circuitry
automatically disconnects the channel’s rear-panel mic and line inputs when a cable is inserted into
that channel’s Hi-Z input. (See page 17 for interconnection diagrams)
Step 6: If you are using a microphone or line-level input, set the channel’s front panel Input Select
switch to Mic or Line.
Step 7: Set the channel’s Meter switch to DRIVE (its down position).
Step 8: Set the channel’s Gain control to “0” and the Level control to approximately “5”.
Step 9: Set the channel’s Blend knob to its twelve o’clock position. This ensures an equal blend of
both of the 4-710d preamplifiers (solid-state and vacuum tube).
Manual conventions:
!Means that this is an especially useful tip
Means that this is an especially important bit of information
And when we need to direct you to a page or section elsewhere in the manual, we’ll use the universal signs
for rewind () or fast forward ().

Getting Started
8
Step 10: Make sure the Power switch is off (down position) and then connect the supplied IEC power
cable to the rear panel AC power connector.
Step 11: Power on the 4-710d. The front-panel meters will light up.
Step 12: If a microphone requiring 48 volts of phantom power is connected to the 4-710d, turn on the
channel’s +48V switch.
Step 13: Unmute your monitors and slowly raise the channel’s Gain control. You should now be
hearing signal, with that channel’s meter becoming active.
Step 14: While viewing the meter, set the channel’s Gain control until optimum input signal strength
is achieved. Change the channel’s Meter switch to OUTPUT (its up position) and set the Level control
until optimum output signal strength is achieved.
Step 15: Experiment with differing degrees of Gain to hear the various amounts of coloration the 4-
710d can impart to your signal. (CAUTION: Very high Gain settings will result in significant amounts of
distortion). For the cleanest, most uncolored signal from the 4-710d, set the Gain knob to its lowest
usable setting, change the Meter to OUTPUT, and then adjust the Level control as necessary. If you
hear distortion when using a connected microphone even at the lowest Gain level, employ the -15 dB
pad to reduce the input level. If you hear low frequency rumble, employ the Low Cut filter switch.
Step 16: Finally, experiment with the Blend control to hear the different sonic signatures imparted by
the two discrete preamplifiers contained within the 4-710d. At the fully counterclockwise (TRANS)
position, only signal from the solid-state preamplifier is heard. At the fully clockwise (TUBE) position,
only the signal from the tube preamplifier is heard. Most uniquely, it is the in-between settings that
allow you to access the “twin-finity” of sounds offered by the 4-710d and create a custom blend that
best complements your signal source.
Because the Model 4-710d utilizes a tube, it needs several minutes to achieve a stable
operating temperature. During warm-up, audio quality may vary slightly.
For more detailed information, refer to the “Front Panel” and “Rear Panel” sections on
pages 9 and 14 of this manual.

9
Front Panel Descriptions
Analog Controls
(1) Hi-Z Inputs -Connect a high impedance signal from an instrument such as electric guitar or bass
to these standard unbalanced 1/4" phone jack connectors. The 4-710d’s jack detection circuitry
automatically switches from the selected rear panel MIC or LINE input to the channel’s front panel Hi–
Z input whenever a plug is inserted into this jack. The Hi-Z input impedance is 2.2MΩfor all four
inputs. These JFET direct inputs provide maximum fidelity with no high-end loss.
(2) Gain - Adjusts the gain of the channel’s input stage. Turning this knob clockwise raises the
amount of gain applied to the input signal. This control also determines the level sent to the
compressor if the compression circuit (#13 on page 11) is engaged.
(3) Blend (“∞”) - This unique control sets the relative contribution from the solid-state and vacuum
tube preamplifier circuits. When in the fully counterclockwise (TRANS) position, only signal from the
solid-state preamplifier is heard. When in the fully clockwise (TUBE) position, only the signal from the
tube preamplifier is heard. At the twelve o’clock position, signal from both the solid-state and tube
preamplifiers is heard at equal amounts.
Making a connection to the 4-710d’s front panel Hi-Z input jack automatically disconnects
any signal arriving at the rear panel mic and line input.
The controls for channels 1-4 are identical, so each control is only described once.

Front Panel
10
(4) Level - This is the channel’s master volume control. It determines the amplitude of the signal sent
to the rear panel LINE OUTPUT (#8 on page 16) and INSERT SEND (#11 on page 16) jacks. This
control also sets the level sent to the A/D converter inputs.
(5) +48V -Most modern condenser microphones require +48 volts of phantom power to operate. When
in the up position, 48 volts of phantom power are available at the channel’s rear panel MIC INPUT.
(See page 21 for more information about phantom power)
(6) -15 dB PAD - When enabled (placed in the up position), the channel’s MIC INPUT signal will be
reduced by 15 dB (this switch has no effect on LINE INPUT or Hi-Z signal). Use the PAD to reduce the
incoming signal in cases where undesired distortion is present at low gain levels (for instance, where
especially sensitive microphones are used on loud instruments or if the A/D converter is clipping).
(7) Input Select - Determines whether the channel’s MIC (up position) or LINE (down position) input is
active. If the channel’s Hi-Z input is in use, this switch has no effect.
(See “Analog Connectors” on page 15 for more info on the rear panel inputs)
(8) Meter - This standard VU meter can display the channel’s overall output level, tube drive level, or
amount of compressor gain reduction. The function that is displayed depends upon the setting of the
Meter Function switch (#9 on page 11).
Keep phantom power off (switch down) when it is not required.
To avoid loud transients, always make sure phantom power is off when connecting or
disconnecting microphones.
Always check the power requirements of your microphone with the manufacturer before
applying phantom power.
The numeric values for the Gain and Level knobs are relative scale markings and do not
represent specific dB values.
!You can come up with many useful tonal variations by experimenting with different Gain
and Level settings.

Front Panel
11
(9) Meter Function - This three-position switch determines what the channel’s VU meter displays. In
the up (OUTPUT) position, it shows the final output level in dB. "0" on the VU meter corresponds to +4
dBu at the analog outputs and -16 dBFS at the A/D converter inputs. In the down (DRIVE) position, it
shows the input level to the tube stage after the front panel Gain control, but before the Blend and
Level controls, thus giving an accurate gauge of how hard the tube and solid-state preamplifiers are
being driven. In the center (GR) position, the meter displays the amount of gain reduction occurring in
the channel’s compressor if the COMP switch (#13 below) is engaged for the channel. If the
channel’s compressor is off, the meter will not deflect from zero when set to GR.
When the switch is in DRIVE mode, the meter is calibrated so that 0 VU is equal to 1.2% THD on a 1kHz
sine wave. When OUTPUT is selected, a meter reading of 0 VU corresponds to a level of +4 dBu at the
rear panel LINE OUTPUT jack.
(See “Drive Metering” on page 25 for additional analog metering info)
(10) Low Cut - When enabled (placed in the up position), the channel’s input signal passes through a
75 Hz low cut filter. This is normally used to eliminate rumble and other unwanted low frequencies
from an incoming signal.
(See page 21 for more information about low cut filtering)
(11) Polarity (“ø”) - Determines the polarity of the channel’s LINE OUTPUT (#8 on page 16) and
the polarity of the signal at the A/D converter inputs. When off (in the down, IN ø position), pin 2 of the
LINE OUTPUT is hot (positive). When the switch is enabled (in the up, OUT ø position), the output signal
is placed out of phase and pin 3 of its LINE OUTPUT is hot (positive). Normally the switch should be off
and only enabled when it is desirable to reverse the polarity, i.e., in cases where more than one
microphone is utilized in recording a source signal.
(See page 21 for more information about polarity inversion)
(12) Insert – When enabled (placed in the up position), the input signal is routed through the chan-
nel’s insert jacks on the rear panel (“Insert Loop” on page 16) for external processing. When
disengaged (in the down position), the signal at the return jack is ignored. The insert switch allows you
to leave external processors conveniently connected when you don’t want to currently use them on the
channel.
(13) Comp – This three-position switch controls the channel’s 1176-style analog compressor. The
compressor has a compression ratio of 4:1 and the threshold is 10 dBu.
When in the up (FAST) position, the compressor attack time is 0.3 ms and the release time is 100 ms.
When in the down (SLOW) position, the attack time is 2.0 ms and the release time is 1100 ms.
If the METER FUNCTION switch (#9 above) is set to GR, the amount of compressor gain reduction is
displayed in the METER.
!The Send jack is active even when Insert is disengaged, so you can route the channel’s
signal to a monitor mix, tuner, etc.

Front Panel
12
Digital Controls
(14) Power - Turns the 4-710d power on or off. When powered on, the front panel meters light up.
(15) Bit Depth – This switch determines the bit depth, or resolution, of the digital output signal for all
eight A/D channels. In the up position, the digital output word length is 24 bits; in the down position,
the digital output word length is 16 bits.
The actual A/D conversion of the 4-710d is always performed at a 24-bit word length. When the switch
is set to 16-bit mode, the 24-bit signal is triangular dithered to 16 bits.
(16) Limit 1-8 – This switch activates the built-in analog limiter for all eight inputs prior to A/D
conversion. The limiter is global for all eight inputs; it cannot be individually enabled per channel
(unlike the mic pre compressors on channels 1-4).
The limiter threshold is 17dBu (= -3dBFS) and the ratio is effectively infinite. The attack time is 0.075
ms and the release time is 100 ms. Although the limiter will help prevent “digital overs” (A/D clipping)
during conversion, it is not a “brick wall” limiter. It is still possible to clip the A/D input, especially
with very hot signal levels and/or signals with fast transient peaks.
(17) Sample Rate - This knob defines the internal sample rate of the A/D converter or selects external
clocking. The following sample rates are supported (kHz): 44.1, 48, 88.2, 96, 176.4, and 192.
When Sample Rate is set to W/C (external word clock) the 4-710d is a word clock slave and the
incoming clock rate at the rear panel’s BNC Word Clock In connector (  #2 on page 14) is used to
determine the sample rate for A/D conversion.
(For more details, please see the “Digital Clocking Primer” section on page 23)
The 4-710d should be powered off when it is not being used for extended periods of time.

Front Panel
13
(18) Digital Out Level - These LEDs indicate the signal level of the A/D converters. Each of the eight
A/D channels has its own two-segment level indicator.
The lower LED illuminates green when the incoming signal is between -37 dBFS and -6 dBFS. This LED
displays the signal level continuously (it does not have peak/hold functionality).
The upper LED is a two-state indicator. When the incoming signal is between -6 dBFS and -1 dBFS, the
LED is yellow; the LED is red when the signal exceeds -1 dBFS. This LED has a peak/hold
implementation; signal peaks are “held” for 90 ms.
(19) Lock - When the 4-710d is locked (synchronized) to a clock source, the LOCK indicator glows
green. The indicator glows red when the clock is not locked. The clock is always locked when the
Sample Rate knob (#17 on page 12) is set to an internal sample rate. For the clock to be locked
when the clock source is external, a valid clock signal must be present at the rear panel word clock
input (see note above).
In order for the 4-710d to detect and lock to a valid external word clock, the frequency of
the incoming word clock must be within ±3% of any of the supported sample rates (44.1,
48, 88.2, 96, 176.4, or 192 kHz). If the frequency of the incoming work clock is not within
±3% of a supported sample rate, the LOCK indicator will glow red, the WORD CLOCK OUT
will be driven at 48 kHz, and the digital outputs will be driven at 48 kHz and muted.
The clock must be locked for proper A/D conversion.
If the clock won’t lock when the Sample Rate knob is set to W/C (external word clock),
verify that the external device is connected to the word clock BNC input and is transmitting
a valid clock signal.
The 4-710d cannot lock to an external device that is set to slave to the 4-710d!

14
Rear Panel Descriptions
Digital Connectors
(1) AES/EBU Out – All eight channels of the 4-710d’s A/D converters are output in AES/EBU digital
format on this standard DB-25 connector. The 4-710d AES/EBU output supports “Single Wire” mode at
all available 4-710d sample rates. The AES/EBU output does not support “Dual Wire” mode at sample
rates above 96 kHz.
(The DB-25 connector pin-out assignments are detailed in Maintenance on page 34)
(2) Word Clock In – The 4-710d’s internal clock can be synchronized (slaved) to an external master
clock. This is accomplished by setting Sample Rate knob (page 12) to “W/C,” connecting the
external word clock’s BNC connector to the Word Clock “In” port, and setting the external device to
transmit word clock.
The frequency of the incoming word clock must be within ±3% of any of the supported sample rates. If
not, the LOCK indicator will glow red, the word clock OUT will be driven at 48 kHz, and the digital
outputs will be driven at 48 kHz and muted.
External clocking is required when connecting the 4-710d to another digital device, such as a com-
puter audio interface, whose digital clock is set to internal (making that device the “master” clock). All
digital devices in a system should be “slaved” to the master clock, otherwise clicks and/or pops could
be encountered when recording or monitoring the digital audio stream from the 4-710d.
(For more details, please see the “Digital Clocking Primer” section on page 23)
Digidesign’s 192 I/O supports AES/EBU at sample rates above 96 kHz only in Dual Wire
mode. Therefore the 4-710d is incompatible with the 192 I/O when connected via AES/EBU
at sample rates of 176.4 kHz and higher.
The 4-710d can be synchronized to an external “1x” clock signal only. Superclock,
overclocking, and subclocking are not supported.

Rear Panel
15
(3) Word Clock Out – This BNC connector transmits a standard (1x) word clock. For all settings except
W/C, the 4-710d is the clock master and the clock rate sent by this port is specified by the Sample
Rate knob (#17 page 12). The 4-710d will drive the Word Clock to all devices on the chain.
When the Sample Rate is set to W/C (external word clock), the 4-710d is a word clock slave. If the
incoming external word clock is within ±3% of a supported sample rate (44.1 kHz, 48 kHz, 88.2 kHz,
96 kHz, 176.4 kHz, 192 kHz), Word Clock Out will mirror Word Clock In with a slight phase delay (about
40ns). If the incoming external word clock is not within ±3% of a supported sample rate, Word Clock
Out will default to 48kHz, and the digital outputs will be muted.
Word Clock Out does not truly mirror Word Clock In, so Word Clock Out should not be used to daisy
chain the Word Clock if the 4-710d is in the middle of the Word Clock chain. The correct method to
connect the 4-710d in the middle of a Word Clock chain is to use a T-connector at the 4-710d Word
Clock input, and leave the 4-710d Word Clock Out unconnected.
(For more details, please see the “Digital Clocking Primer” section on page 23)
(4) 75ΩTermination – This pushbutton switch provides internal word clock termination when
required. Termination is active when the switch is engaged (depressed).
Word clock termination should only be used at the receiving end of a word clock cable, or, if the cable
is daisy-chained across several units, termination should only be used on the last unit in the chain.
For example, if the 4-710d is the last “slave” unit at the end of a clock chain (when the
4-710d’s word clock “Out” port is not used), termination should be active. If the word clock is passed
through the 4-710d to another unit (when the 4-710d’s Word Clock Out port is connected, passing the
word clock through to another device), termination should be disabled.
(5) ADAT Optical Outputs 1 & 2 – Up to eight channels of the 4-710d’s A/D converters are output in
ADAT optical format using these two connectors. The particular 4-710d channels that are output at
each port depend upon the current sample rate setting. At sample rates of 44.1kHz and 48kHz, all
eight channels are output on both ADAT ports (mirrored). At higher sample rates, industry standard
S/MUX™ multiplexing is used to maintain high-resolution transfers. At rates of 88.2kHz and 96kHz,
channels 1-4 are output on ADAT port 1, while channels 5-8 are output on port 2. At 176.4kHz and
192kHz, channels 1 and 2 are output on port 1, while channels 3 and 4 are output on port 2 (channels
5-8 cannot be output via ADAT optical at the highest rates). These correlating values are shown in the
following table:
Analog Connectors
(6) AC Power Input – Connect a standard, detachable IEC power cable (supplied) here.
(7) Line Inputs 5 through 8 – These four line inputs feed directly into channels 5–8 of the 4-710d’s
A/D converters. Any ¼” phone plug (balanced TRS or unbalanced TS) carrying a line-level signal can
be connected here for output via the AES/EBU or ADAT digital outputs. These inputs are fed into the
limiter when the limiter (#16 on page 12) is enabled.
Sample Rate
Knob Setting:
ADAT Port 1
Output channels:
ADAT Port 2
Output channels:
44.1, 48
1-8
1-8 (mirrored)
88.2, 96
1-4
5-8
176.4, 192
1-2
3-4

Rear Panel
16
Two 4-710d units can combined using these inputs to obtain eight mic pre channels on one 8-channel
digital stream. Simply connect the channel 1–4 line outputs of the first unit to the line inputs 5–8 of
the second unit; the digital outputs of the second unit will now contain the combined mic pres of both
units!
Note: There are no analog outputs for line inputs 5–8.
(8) Line Output - A balanced XLR connector that carries the line-level output signal of the 4-710d
channel. Note that Pin 2 is positive when the front panel Polarity switch (#11 on page 11) is off (IN
ø). Pin 3 is positive when the front panel Polarity switch is engaged (OUT ø).
(9) Line Input - Connect any line-level input signal (coming from a device such as a mixer, DAW, tape
machine, or signal processor) into this balanced XLR connector. Pin 2 is wired positive (hot).
Any ¼” phone plug line-level output can also be connected to the Insert Return jack (  #12 below),
and if the Insert switch for the channel (#12 on page 11) is engaged, that signal will be used for
the channel input instead of the XLR line input.
(10) Mic Input - Connect a microphone to this standard XLR connector. Pin 2 is wired positive (hot).
+48V phantom power is available via the front panel switch.
Insert Loop - An external audio processor (for example, EQ or compressor) can be inserted into the
analog path of channels 1-4 using the Insert Loop for additional processing of the channel’s signal
using the Send and Return jacks (#11 and #12 below). The Insert Loop can be enabled or disabled
using the Insert switch for the channel on the front panel (#12 on page 11).
(11) Insert Send – Connect this jack to the audio input of the external processor. The signal at this
jack is post-preamp, so all level and sonic changes made with the associated channel’s front panel
controls will be reflected here. The jack is “half-normalled” which means you can extract the channel’s
signal from here even if you don’t use the associated Insert Return. This is handy for routing the signal
to a monitor mix, tuner, etc.
The signal at the Insert Send jack is identical to the signal at the XLR Line Output jack. Both channel
outputs can be used simultaneously without any signal loading issues.
(12) Insert Return– Connect this jack to the audio output of the external processor. The signal at this
jack is only audible if the associated channel’s Insert switch on the front panel (#12 on page 11) is
engaged.
The Insert Return jack can be used as a ¼” line input for the channel in lieu of the XLR input. The
Insert Return is used as the input when the channel’s Insert switch (#12 on page 11) is engaged.
Since the connectors for channels 1–4 are identical, each is only described once below.
All Insert connections accept standard ¼” male phone plugs. Balanced TRS and
unbalanced TS connectors can be used.

17
Interconnection Diagrams
Analog-Only Setup
This diagram illustrates a typical system using the 4-710d in an analog-only configuration, such as
when using it as the front end to a public address system or analog recording device. In this setup, the
digital features of the 4-710d are not used.
The example shows a microphone connected to channel 1, a keyboard connected to the insert return of
channel 2 (to use the ¼” line input instead the XLR line input), and a guitar connected to channel 3
using the Hi-Z input. A signal processor (e.g., reverb) is connected via the insert loop of channel 1 for
the mic. The insert send of channel 3 (but not the return) is used as a guitar direct output for
connection to a tuner. The line outputs are connected to an analog mixer where the input signals are
combined before being sent to powered PA speakers.
Key points for this example:
•Mic/Line switch for channel 1 is set to “Mic”
•Insert switches for channels 1 and 2 are set to “In”
•Line outputs are connected to an analog mixer for monitoring

Interconnections
18
Basic Digital Setup
This diagram illustrates a typical system using the 4-710d as the front end of a digital recording
setup. A variety of input sources are used, with the 4-710d performing A/D conversion on the inputs. In
this setup, the converted input signals are sent to the computer digitally via the ADAT lightpipe, and
the software monitoring features of the DAW are used to monitor the 4-710d inputs.
The example shows microphones connected to channels 1 and 2, guitar and electric bass connected to
the H-Z inputs of channels 3 and 4, and a stereo keyboard connected to line inputs 5 and 6. A guitar
effects processor is connected via the insert loop of channel 3. The insert send of channel 4 (but not
the return) is used as a bass direct output for connection to a tuner. The ADAT output from the 4-710d
is connected to the ADAT input of the computer’s audio interface for monitoring and recording.
Key points for this example:
•Mic/Line switch for channels 1 and 2 are set to “Mic”
•Insert switch for channel 3 is set to “In”
•ADAT output is connected to computer audio interface
•Internal clock is used (Sample Rate knob is NOT set to “W/C”)
•Computer is set to synchronize (“slave”) to ADAT external clock
•Computer DAW is used for software monitoring

Interconnections
19
Advanced Digital Setup
This diagram illustrates a typical system using the 4-710d as the front end of a more complicated
digital recording setup. A variety of input sources are used, with the 4-710d performing A/D conversion
on the inputs while slaved to an external word clock. In this setup, the converted input signals are sent
to the computer digitally via the AES/EBU output, and the software monitoring features of the DAW are
used to monitor the 4-710d inputs.
(See the “Digital Clocking Primer” on page 23 for detailed info about synchronization)
The inputs and inserts are connected as in the previous example. The AES/EBU output from the 4-710d
is connected to the AES/EBU DB-25 input of the computer’s audio interface, and the word clock output
is connected from the audio interface to the 4-710d word clock input. The software monitoring features
of the DAW are used to monitor the 4-710d inputs.
Key points for this example:
•Mic/Line switch for channels 1 and 2 are set to “Mic”
•Insert switch for channel 3 is set to “In”
•AES/EBU output is connected to computer audio interface
•Word clock out from audio interface is connected to 4-710d word clock input
•Sample Rate knob is set to “W/C” (external clock synchronization is used)
•Computer DAW is used for software monitoring

20
Model 4-710d Overview
The Universal Audio 4-710d, with its four mic preamps derived from our TEC award-winning UA Model
710 Twin-Finity Mic/Line/Hi-Z Preamplifier, combines our highly revered analog tube and solid state
preamplification technology... but with a twist. Its unique phase-aligned Blend controls allow the user
to literally dial in the desired sound, from precise ultra-clean solid-state tones to fat tube presence
and overdriven crunch, or anywhere in between. Additionally, each of the four mic preamp channels
has an 1176-style analog compressor that can be individually enabled for each channel.
Other features include JFET Direct Inject inputs (which allows for the direct connection of an electric
guitar or bass, or any instrument with a magnetic or acoustic transducer pickup); monolithic balanced
output stages; +69 dB of gain; +48V power and a -15 dB pad for the mic inputs; polarity inverts and
75 Hz low cut filters; output and “Drive” (input) VU metering; a universal auto-sensing internal power
supply that allows for operation at any voltage between 100 and 240VAC; and a 2U, rack-mountable
design for studio or stage.
4-710d Vacuum Tube Preamp
The 4-710d high voltage (285 VDC) Class-A tube preamp section is based upon both classic guitar
amplifier design and classic tube mic preamp design. The circuit utilizes a 12AX7 tube for warmth and
roundness and is the second gain stage, located downstream from the Gain control pot. This allows
the circuitry to be overdriven by the first stage into anything from mild harmonic distortion to all-out
grunge; however, the transition to tube saturation is extremely gentle. The result is the gradual onset
of harmonic overdrive—no hard clipping here. As an example, the transition from 1% THD to 4% THD
occurs over a 14 dB range. Because of its multiple gain stages, with a Gain control pot between them
(as well as a Drive Meter that displays the signal level entering the second stage), a wide variety of
tonal possibilities can be dialed in, from gentle warmth to extreme grit.
4-710d Solid-State Preamp
The 4-710d solid-state preamp circuitry utilizes Universal Audio’s transimpedance design for precision
sound and ultra-low distortion, delivering the highest possible quality of signal from input to output.
The term “transimpedance” refers to transistor configurations that employ current feedback to provide
gain and distortion immunity without the loss of sonic detail or musicality. Designed for applications
requiring the ultimate in transparent amplification with little or no coloration, its razor flat and
immensely wide frequency response yields highly accurate results and minimizes artifacts on the way
to the recording medium.
Noise and distortion are kept to near-theoretical minimums so critical signals may be generously
amplified without degrading the quality or character of the sound source. Zero-coloration preamps
such as these are especially useful for capturing the sound source with its original qualities and
character so that later processing may occur with maximum flexibility. There are no transformers or
tubes in the preamp signal path, and the 1176-style compressor/limiter (located after the
preamplifier) can be switched out as desired to eliminate permanent audio coloration. For many users,
the useful characteristics of these devices are preferred at the mix stage—and are commonly
implemented using DSP processors and plug-ins with excellent (and reversible) results, such as those
found on Universal Audio’s UAD plug-in platform.
About “Class A”
Most electronic devices can be designed in such a way as to minimize a particularly unpleasant form
of distortion called crossover distortion. However, the active components in “Class A” electronic
devices such as the 4-710d draw current and work throughout the full signal cycle, thus eliminating
crossover distortion altogether.