Digidesign Inc.

3401-A Hillview AvenuePalo Alto, CA 94304 USA

tel: 6508427900fax: 6508427999

Technical Support (USA)

65084266996508564275

Product Information

65084266028003332137

Digidesign888|24 I/O Audio Interface

Installation GuideFax on Demand1-888-USE-DIGI (873-3444)

World Wide Webwww.digidesign.com

Digidesign FTP Siteftp.digidesign.com

Copyright

This Users Guide is copyrighted 1999 by Digidesign, a division of Avid Technology, Inc. (hereafter Digidesign), with all rights reserved. Under copyright laws, this manual may not be duplicated in whole or in part without the written consent of Digidesign.

DIGIDESIGN, AVID and PRO TOOLS are trademarks or registered trademarks of Digidesign and/or Avid Technology, Inc. All other trademarks are the property of their respective owners.

All features and specifications subject to change without notice.

PN 932707455-00 REV A 11/99

Communications & Safety Regulation Information

Compliance Statement

The model 888/24 I/O complies with the following standards regulating interference and EMC: FCC Part 15 Class A EN55103 1, environment E4 EN55103 2, environment E4 AS/NZS 3548 Class A CISPR 22 Class A

Radio and Television Interference

This equipment has been tested and found to comply with thelimits for a Class A digital device, pursuant to Part 15 of theFCC Rules.

Communications Statement

This equipment has been tested to comply with the limits for aClass A digital device. Changes or modifications to this product not authorized by Digidesign, Inc., could void the Certification and negate your authority to operate the product. This product was tested for CISPR compliance under conditions that included the use of peripheral devices and shielded cables and connectors between system components. Digidesign recommends the use of shielded cables and connectors between system components to reduce the possibility of causing interference to radios, television sets, and other electronic devices.

Safety Statement

This equipment has been tested to comply with USA and Canadian safety certification in accordance with the specifications of UL Standards; UL813 and Canadian CSA standard; CSA C22.2 No.1-M90. Digidesign Inc., has been authorized to apply the appropriate UL & CUL mark on its compliant equipment.

Important Safety Instructions

When using electric or electronic equipment, basic precautionsshould always be followed, including the following: Read all instructions before using this equipment. To avoid the risk of shock, keep this equipment away from

rain water, and other moisture. Do not use this equipment if it is wet.

The equipment should only be connected to the correct rating power supply as indicated on the product.

Do not attempt to service the equipment. There are no user-serviceable parts inside. Please refer all servicing to authorized Digidesign personnel.

Any attempt to service the equipment will expose you to a risk of electric shock, and will void the manufacturers warranty.

The product should be connected only to the correct power supply as indicated on the product.

contents

Using the 888/24 I/O

. . . . . .

The 888/24 I/O Interface

.

Changing Operating Levels

Making Signal Connections

Using the 888/24 I/O Interf

Changing the Default Samp

Changing the Default Word

Muting the DAC Outputs of

Appendix A. Technical Specif

Appendix B. Calibrating the 8

About Calibration

. . . . . . .

Calibrating The 888/24 I/O

Appendix C. Calibrating the 8

About Calibration

. . . . . . .

Calibrating The 888/24 I/O

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

of Individual 888/24 I/O Channels . . . . . . . . . . . . . . . . . . . . . . . . 6

to the 888/24 I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

ace as Stand-Alone Audio Converter . . . . . . . . . . . . . . . . . . . . . . . 8

le Rate of the 888/24 I/O in A/D Stand-Alone Mode . . . . . . . . . . . 9

Clock Lock Port of the 888/24 I/O in D/A Stand-Alone Mode . . . . 10

the 888/24 I/O in A/D Stand-Alone Mode . . . . . . . . . . . . . . . . . . 11

ications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

88/24 I/O (Pro Tools 5.0) . . . . . . . . . . . . . . . . . . . . . . . 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

88/24 I/O (Pro Tools 4.x) . . . . . . . . . . . . . . . . . . . . . . . 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Contents iii

888/24 I/O

iv

Using the 888/24 I/O

The 888/24 I/O

is an 8-channedio interface that features 24-bdigital, and 24-bit digital-to-anverters for superior dynamic rannoise floor, and the capability tthe full 24-bit mixing, editing, and mastering environment of

The 888/24 I/O can be used in

u

As a 24-bit Audio Interface fo

u

As a stand-alone 24-bit audio

This Users Guide explains the and connectors on the 888/24 explains how to use it with a DPro Tools

system, or as an indestand-alone 24-bit audio convestudio.

+

If you own a Pro Tools system,information in this guide is covere

Pro Tools TDM Hardware Installa

and the digital-to-analog converters

Using the 888/24 I/O 1

(DACs).l digital au-it analog-to-alog con-ge, reduced

o work with processing, Pro Tools.

two ways:

r Pro Tools

converter

indicators I/O. It also igidesign pendent, rter in your

most of the d in your tion Guide.

The 888/24 I/O InteThis section explains each of thtors and indicators on the fronpanels of the 888/24 I/O Interfthey are used, and offers suggeconnecting the 888/24 I/O to y

888/24 I/O Front PaneThe 888/24 I/O has the followipanel indicators, moving from

1. Power

This switch applies power to thThe I position is on. The Ooff.

2. Sync Mode

The Sync Mode LEDs indicate wple rate clock reference is currenthe analog-to-digital converter

Front panel of the 888/24 I/Orfacee connec-

t and back ace, how stions for our studio.

lng front left to right:

e 888/24. position is

hich sam-tly used by

s (ADCs)

888/24 I/O

2

Internal

This is the 888/24 I/O standard set-ting. In this mode, the 888/24 I/O sample rate is generated by its internal crystal oscil-lator (whose frequency is determined by the Sample Rate setting in the Session Setup window). Internal mode should be active whenever the 888/24 I/Ochronized to an external clock

Digital

This setting indicates thAES/EBU or S/PDIF word clock srently the source for the 888/24rate. This is the setting to use fomaterial from DAT recorders ortal devices.

To use the 888/24 I/O digital inoutputs as effects sends and retital effects devices, you should 888/24 I/O to Internal Sync Moshould then set the digital effecaccept an external digital clock888/24 I/O) so it synchronizes Pro Tools.

The 888/24 I/O can only synchand receive word clock lock on12 of its digital inputs. To synyour system to an external digisource, it must be connected toputs 12 of the 888/24 I/O. In aPro Tools system, the system clried by the Audio Interface conthe first Pro Tools card in your sAudio Interface will act as the mface in your system. All other Afaces will be slaved to it.

s

Because some digital audio devices do not output proper clock when they are not playing back, leaving the 888/24 I/O in Digital Sync Mode may cause Pro Tools audio playback quality to suffer, or play back at the wrong pitch. If you are using digital I/O, reset the

is not syn-source.

at an ignal is cur- I/O sample r inputting other digi-

puts and urns to dig-set the de. You ts device to (from the itself to

ronize to channels chronize tal clock digital in-

n expanded ock is car-nected to ystem. This aster inter-

udio Inter-

Sync Mode from Digital to Internating material.

Slave This LED is lit when the 8sample rate is synchronized to Digidesign Audio Interface or stion peripheral. In this mode, trate of the slave interface is derthe frequency of the incomingclock signal present at the Slav(256x) port.

The 888/24 I/O automatically sthis mode when a Slave Clock from another Digidesign Interfsal Slave Driver, Video Slave DrSMPTE Slave Driver is connecte888/24 I/O Slave Clock In port

In expanded Pro Tools systemsClock output of the master Audlocks all other interfaces togethsample accuracy, keeping all sigsynchronous.

] When slaving to a Digidesign USlave Driver, Video Slave Driver, oSlave Driver, set the clock sourceThe Audio Interface will automaticSlave mode when it detects the 2clock.l after input-

88/24 I/O another ynchroniza-he sample ived from master e Clock

witches to Out signal ace, Univer-iver, or d to the

.

, the Super io Interface er with nals phase-

niversal r SMPTE to Internal. ally switch to 56x input

3. Sample Rate and 12 Format Indicators

These LEDs indicate the sample rate of the 888/24 I/O internal crystal oscillator and the digital format (AES/EBU or S/PDIF) of the audio input signal to channels 1 and 2.

The choice of digital format forchannels is made in the Sessiondow or Hardware Setup dialog.put pairs 34, 56, and 78 of t888/24 I/O are always AES/EBURate is set in the Session Setup Hardware dialog in Pro Tools.

The 888/24 I/O provides the fosample rates:

48 kHz

This is a standard sampmany professional audio devicommended for use with devicenot receive digital transfers at 4

44.1 kHz

This is the compact disampling rate and the Pro Toolsample rate. To avoid the needrate conversion, you should uswhen you are recording materiultimately be published on a co

s

When you are using an externasource such as a DAT recorder, thof the 888/24 I/O indicates onlyoscillator sample rate, not that of

digital source.

4. Level Meters

The 888/24 I/O level meters mchannel outputs of Pro Tools. Iare monitored on-screen in thesoftware.

The 888/24 I/O is factory calibrated so that a meter reading of 18 dB corresponds to the 888/24 I/O nominal operating level (which can be set to either +4 dBu or 10 dBV). If you sent the output to an ana-log device with a VU meter, this would cor-

Using the

these two Setup win-

Digital in-he . Sample window or

llowing

ling rate of es. It is rec-s that can-4.1 kHz.

sc standard s default for sample e this rate al that will mpact disc.

l digital e front panel the internal the external

onitor the nput levels Pro Tools

respond to 0 VU on the VU m

The red LED indicators on the face indicate both full-code (hibefore clipping) and clipping ooutput signals. The on-screen mPro Tools software indicate clipat least three consecutive full-cofollow each other.

5. Input Level Trims

The 888/24 I/O analog inputs acalibrated at a 18 dB nominalenced to a full code signal. Thithe nominal reference input le+4 dBu or 10 dBV), you have 1headroom before clipping. Thetrim pots allow adjustment of t888/24 I/O input levels to matcating level of your external equjustments can be made with a screwdriver.

6. Output Level Trims

The 888/24 I/O analog outputscalibrated at a 18 dB nominalenced to a full code signal. Thithe nominal reference output l+4 dBu or 10 dBV), you have 1headroom before clipping. Thelevel trim pots allow adjustmen888/24 I/O output levels to maerating level of your external eAdjustments can be made withscrewdriver. 888/24 I/O 3

eter.

Audio Inter-ghest level f Pro Tools eters in

ping when de samples

re factory level, refer-s means at vel (either 8 dB of

input level he h the oper-ipment. Ad-Phillips

are factory level, refer-s means at evel (either 8 dB of

output t of the

tch the op-quipment. a Phillips

888/24 I/O

4

To calibrate the input and output levels of the 888/24 I/O to match your mixing con-sole or other devices in your studio, use Calibration Tool (for Pro Tools 4.3.1 and earlier) or use Calibration Mode and the Signal Generator Plug-In (for Pro Tools 5.0 or later).

+

Instructions for calibrating the

appear in Appendix B of this Guid

888/24 I/O Back Pane

The 888/24 I/O has the followipanel connectors, moving fromright:

1. Analog Audio Outputs

These are balanced male XLR cfor analog audio output conneeight output channels are conttive. The 888/24 I/O analog out24-bit digital-to-analog convert

2. Analog Audio Inputs

These are balanced female XLRfor analog audio input connect888/24 I/O analog inputs featualog-to-digital converters. Becachannels 18 of the 888/24 I/Oware selectable in pairs betweedigital format, analog input to

pair is disabled when digital input format is chosen for that channel.

The 888/24 I/O analog audio connectors are balanced XLRs with pin 2 wired hot, (or +); pin 3 cold, (or ); and pin 1 ground.

Back panel of the 888/24 I/O888/24 I/O e.

lng back left to

onnectors ctions. All inuously ac-puts feature ers.

connectors ions. The re 24-bit an-use input are soft-

n analog or a channel

3. AES/EBU Digital Outputs

The 888/24 I/O AES/EBU outpubalanced, three conductor, XLRwhich output a 24-bit digital dOutput is continuously active oAES/EBU and S/PDIF jacks even888/24 I/O input selector is set

4. AES/EBU Digital Inputs 1

The AES/EBU digital format is umany professional digital audiocluding some DAT recorders. Tfaces AES/EBU input jacks are three conductor, XLR connectocept a full 24-bit digital data st

For AES/EBU connections, 110-are highly recommended for ussional installations. For best reslengths should not exceed 30 m

Input channels 18 of the 888/software-selectable in pairs betwor digital format. Digital input tpair is disabled when analog inis chosen for that channel in thSetup dialog. Input to AES/EBUnels 12 is disabled when S/PDImat is chosen for these inputs Pro Tools Session Setup window 18

t jacks are connectors ata stream. n both the when the

to analog.

8

sed in devices, in-he Inter-balanced, rs which ac-ream.

ohm cables e in profes-ults, cable eters.

24 I/O are een analog

o a channel put format e Hardware input chan-F digital for-in the

.

5. 50-pin Interface Connector

This 50-pin Computer connector is used to connect the 888/24 I/O to a MIX card, d24 audio card, Disk I/O card, or a DSP Farm card. The necessary cable is supplied with your Audio Interface. If you plan to con-nect two 888/24 I/O Interfacescard or d24 card, a 16-channel cable adapter is necessary. (Thiavailable from your Digidesign

6. S/PDIF Digital Input/Out

The Sony Phillips Digital Interf(S/PDIF) is used in many profesconsumer CD players and DATThe 888/24 I/O S/PDIF in/out jbalanced 2-conductor phono (Rwhich utilize a full 24-bit digitastream. To avoid RF interferencohm coaxial cable for S/PDIF trkeep the cable length to a maximeters.

Because input channels 12 of 888/24 I/O are software selectabanalog or digital format, input tdigital channels is disabled whinput is chosen or when AES/Eformat is chosen in the Pro TooSetup window. Output is contitive on both the AES/EBU and put jacks, regardless of which dformat is selected for channels avoid RF interference, use 75-ocable for S/PDIF transfers and dceed a cable length of 10 meter

7/9. Slave Clock In/Out

The Slave Clock Out jack is a standard BNC type connector that outputs a 256 times sample rate Super Clock signal for slaving and synchronizing multiple Digidesign In-terfaces and synchronization peripherals

Using the

to a MIX peripheral s cable is dealer.)

put

ace Format sional and recorders. acks are un-CA) jacks l data e, use 75-ansfers and mum of 10

the le between o these two en analog BU digital ls Session

nuously ac-S/PDIF out-igital input 12. To hm coaxial o not ex-s.

together.

When the 888/24 I/O Sync MoInternal, connecting a valid SlaOut signal to this port will cau888/24 I/O to automatically swimode. When the 888/24 I/O isinterface or the first interface inDigital sync mode overrides thClock input, and an incoming Out signal will not switch the 8to Slave mode.

Because crucial timing data is pthese ports, you should use hig75-ohm RG-59 cables for makintions, and keep total cable lengthan 3 meters between interfac

8. Power Input

This connector accepts a standpower cable. The Interface is auselecting (100V to 240V) and wically work with a standard moto connect to AC power receptacountry. 888/24 I/O 5

de is set to ve Clock

se the tch to Slave the master a chain,

e Slave Slave Clock 88/24 I/O

assed over h-quality, g connec-

th to less es.

ard AC to power-ill automat-dular cable cles in any

888/24 I/O

6

Changing Operating Levels of Individual 888/24 I/O Channels

The 888/24 I/O is factory set to +4 dBu op-erating levels for input and output. How-ever, the 888/24 I/O allows youually switch any of its analog ioutputs to either a +4 dBu or 1ating level by moving internal its circuit board.

To change the operating level ofchannel:

1

Turn off your computer and 888/24 I/O.

2

With a Phillips screwdriver, rscrews from the top of the 888

3

Using the 1/16-inch hex wrecluded with the 888/24 I/O, camove the front four panel screwon the bag containing the hex

4

Lift the top off of the 888/24

5

Inside the 888/24 I/O chassiseach of the channel input trimjumper switch with a removab

cate the jumper switch for the channel you wish to modify. Gently lift the cap off the 3-pronged connector. Place it in the posi-tion corresponding to the operating level that you desire. For +4 dBu levels, it should be placed over the rear two prongs. For

The location of input and output level sthe 888/24 I/O

output leveladjustment switche+4 dBu or -10 dBV

input leveladjustment switches+4 dBu or -10 dBV

to individ-nputs or 0 dBV oper-jumpers on

an input

the

emove the /24 I/O.

nch in-refully re-

s as noted wrench.

I/O.

, next to s, there is a le cap. Lo-

10 dBV levels, it should be placfront two prongs.

6 After you have made the desirreplace the top of the 888/24 I/

7 Replace the four front panel sthe hex wrench.

8 Replace the top screws with screwdriver.

To change the operating level ofchannel:

1 Turn off your computer and 888/24 I/O.

2 Using the 1/16-inch hex wrecluded with the 888/24 I/O, camove the front four panel screwon the bag containing the hex

3 With a Phillips screwdriver, rscrews from the top of the 888/lift the top off of the 888/24 I/O

4 To find the channel output stach the front part of the ribbothe right side of the chassis. To dboth sides of the black connecttly pull up.

witches inside

s

Setting the input level jumper switche

pull off jumper

place jumperin this position

to set inputto +4 dBu level

i

to

+4 -10+4 -10

+ed over the

ed changes, O.

crews using

a Phillips

an output

the

nch in-refully re-

s as noted wrench.

emove the 24 I/O and .

witches, de-n cable at o this, grip or and gen-

s

place jumpern this positionto set input -10 dBV level

4 -10

5

With the ribbon cable out of the way youll see eight 3-pronged jumper switches, each with a removable cap. Locate the switch for the channel you wish to modify.

6

Gently lift the cap off of the switch. Place it in the position ing to the operating level that For +4 dBu levels, it should be the left two prongs. For 10 dBshould be placed over the right

7

After you have made the desirreconnect the ribbon cable andback on the 888/24 I/O.

8

Replace the four front panel sthe hex wrench.

9

Replace the top screws with screwdriver.

Making Signal Connections to the 888/24 I/O

Depending on how you plan to use the 888/24 I/O, the way you connect it to your studio will vary.

Setting the output level jumper switch

detacribbon c

remove jumper

+4 -10

place jumperin this positionto set output

to +4 dBu level

place jumperin this positionto set output

to -10 dBV levelUsing the

jumper correspond-you desire. placed over V levels, it two prongs.

ed changes, put the top

crews using

a Phillips

Choosing between +4 d10 dBV operation modThe 888/24 I/O can be set to op+4 dBu or 10 dBV input and ouIt is important that you determline level mode is appropriate fdio. In +4 dBu operating mode888/24 I/O is a 24-bit digital aucapable of producing audio signear +26 dBu.

Check the owners manual for power amplifier or effects proceit can handle this load. If it cansider setting the 888/24 I/O to 10 dBV line levels.

Consider the following when comixer:

u If your mixer cannot handle1.5V (RMS) inputs at +4 dBu, thshould set the 888/24 I/O to runline level.

u If your mixer can handle up (RMS) inputs, or has pads or attits inputs, then you can use theting on the 888/24 I/O.

Most manuals contain device incations, including whether or npads or attenuators. Consult thturer of your mixer or power amfurther information.

es

hable 888/24 I/O 7

Bu and eserate at tput levels. ine which or your stu-, the dio device

nals at or

your mixer, ssor to see if not, con-

operate at

nnecting a

more than en you at 10 dBV

to 8.5V enuators on +4 dBu set-

put specifi-ot there are e manufac-plifier for

888/24 I/O

8

Setting Up Your Studio

The following diagram illustrates a typical studio setup, with the 888/24 I/O con-nected to a mixing console, effects and other equipment.

The 888/24 I/O analog audio care balanced XLRs with pin 2 w(or +), pin 3 cold (or ), anground.

If you are connecting a balancepin 1 and shield should be conthe input only (not at the outpuprevent ground loops betweenand pin 1 conductor.

If you are connecting an unbalato the 888/24 I/O inputs or outnect only pin 2 to the + sign1 and 3 to ground at all inputs

Using the 888/24 I/O Interface as Stand-Alone Audio Converter

The 888/24 I/O can be used apart from Pro Tools as a stand-alone 8-channel, 24-

A typical studio configuration

Poweand Sp

Digital Inputs/OutputsChannel 1-2

To DAT Recorder

Digital Inputs/Channel

To Digital Effec

InstrumentsConnected to Console

AnalogAudio

Inputs 5-8

AnalogAudio

Outputs 5-8

Effects Device

D

ChannelOutputs 1-4

Tape Returnsor Inputs 1-4

Computer 1

ANALOG OUT

PUT

ANALOG INPU

T

AES/EBU OU

TPUTAES/E

BU INPUT

S/PDIF

IN

S/PDIF

OUT

SLAVE CLOC

K

IN

SLAVE CLOC

K

OUT

7

8

5

6

3

4

1

2

7

8

5

6

3

4

1

2

5/6

7/8

1/2

3/4

5/6

7/8

1/2

3/4onnectors ired hot

d pin 1

d system, nected at t). This will

the shield

nced signal puts, con-

al, and pins only.

bit, analog-to-digital or digital-converter.

Before you use the 888/24 I/O alone mode:

1 Turn off the 888/24 I/O.

2 Do not turn on your comput888/24 I/O is in stand-alone mdo, the 888/24 I/O will stop funstand-alone mode.

To use the 888/24 I/O as a stanconverter:

1 Turn off any digital devices tsend a word clock signal to thechannel 12 digital input ports

2 Turn on the 888/24 I/O. Thesearches briefly for a word clocchannels 12 of its digital inpu

3 If the 888/24 I/O does not declock, it functions as a stand-alconverter using its internal clomode you will use analog inpuAES/EBU outputs 18.

] The default sample rate of the in stand alone A/D mode is 44.1change this default setting to 48 must open the 888/24 I/O and mset it by moving an internal jumperChanging the Default Sample Ra888/24 I/O in A/D Stand-Alone Mpage 9.

r Ampeakers

Outputs3-4ts Devices

DAT Recorder

s

igital Effects Devices(set to external sync)to-analog

in stand-

er while the ode. If you ctioning in

d alone A/D

hat may 888/24 I/O .

888/24 I/O k signal on t ports.

tect word one A/D ck. In this ts 18 and

888/24 I/O kHz.To kHz, you anually re-

switch. See te of the ode on

To use the 888/24 I/O as a stand alone D/A converter:

1

Make sure that a digital device providing a word clock signal is connected to AES/EBU inputs 12 of the 888/24 I/O and turned on.

2

Turn on the 888/24 I/O. Thewill search for a valid word clocclock signal on channels 12 oinput ports.

3

When a valid word clock locnized, the 888/24 I/O will entesync mode and function as a stD/A converter using AES/EBU iand analog outputs 18.

The 888/24 I/O D/A sample ratmined by the sample rate it dechannels 12 of its AES/EBU in

]

The 888/24 I/O defaults to lisdigital word clock signal on channeAES/EBU digital input ports. To udevice as your source of word clocreset this default by opening the and moving an internal jumper swChanging the Default Word Clockthe 888/24 I/O in D/A Stand-Alon

page 10.

To return the 888/24 I/O to Pro operation:

u

Turn on your computer. or

u

If your computer is on, launc

Changing the Default Sample Rate of the 888/24 I/O in A/D Stand-Alone Mode

Using the

888/24 I/O k or a word f its digital

k is recog-r digital and-alone nputs 18

e is deter-tects on puts.

tening to a ls 12 of its

se a S/PDIF k, you must

888/24 I/O itch. See Lock Port of e Mode on

Tools-based

h Pro Tools.

The default sample rate of the in stand alone A/D mode is 44.1wish to change this default sett48 kHz, you must open the 888manually reset it by moving anjumper switch.

To change the default sample ra888/24 I/O in stand alone A/D

1 Make sure that your comput888/24 I/O are turned off.

2 With a Phillips screwdriver, rscrews from the top of the 888

3 Using the 1/16 inch hex wrecluded with the 888/24 I/O, camove the front four panel screwon the bag containing the hex

4 Lift the top off of the 888/24

5 Inside the left-front of 888/2sis, near the large FPGA chip, isthree jumper switches, each wiable cap. Each of these switchedifferent default function whicin Figure 1 and 2.

6 Locate the jumper switch forthat you wish to modify and gecap off the 3-pronged connecto

7 Place it in the position corresthe value that you desire. For a fault sample rate, it should be pthe right two prongs. For a 48 ksample rate, it should be placedleft two prongs. Refer to Figuredetails. 888/24 I/O 9

888/24 I/O kHz. If you ing to /24 I/O and internal

te of the mode:

er and

emove the /24 I/O.

nch in-refully re-

s as noted wrench.

I/O.

4 I/Os chas- a set of th a remov-s controls a h is shown

the default ntly lift the r.

ponding to 44.1 kHz de-laced over Hz default over the

1 and 2 for

888/24 I/O

10

8

After you have made the desired changes, replace the top of the 888/24 I/O.

9

Replace the four front panel screws using the hex wrench.

10

Replace the top screws with a Phillips screwdriver.

Changing the Default Word Clock Lock Port of the 888/24 I/O in D/A Stand-Alone Mode

Figure 1. jumper switch location in th

Figure 2. Changing jumper switch se

stand alone modedefault word clock lock switches

AES/EBU or S/PDIF

stand alone modedefault sample rate switches

44.1 kHz or 48 kHz

stand alone modeDAC muting switches

in this positionDACs are muted

in this pos44.1 kHz

44.1 kHz48 kHz

unmute DACs

mute DACs

AES/EBUS/PDIF

remove jumper andplace it in desired positionThe 888/24 I/O defaults to listdigital word clock signal on chaits AES/EBU digital input ports.to use a S/PDIF device as your sword clock, you must reset thisopening the 888/24 I/O and mternal jumper switch so that chof its S/PDIF digital input portsstead.

+ Refer to Figure 1 and 2 for detaswitches and their default positio

To change the default word clockthe 888/24 I/O in stand alone D

1 Make sure that your comput888/24 I/O are turned off.

2 With a Phillips screwdriver, rscrews from the top of the 888

3 Using the 1/16 inch hex wrecluded with the 888/24 I/O, camove the front four panel screwon the bag containing the hex

4 Lift the top off of the 888/24

5 Inside the left-front of 888/2sis, near the large FPGA chip, isthree jumper switches, each wiable cap. Each of these switchedifferent default function whicin Figure 1 and 2.

6 Locate the jumper switch forclock lock default (the back-moand gently lift the cap off the 3connector.

e 888/24 I/O

ttings

itionis selectedening to a nnels 1-2 of If you wish ource of default by oving an in-annels 1-2 are used in-

ils on jumper ns.

lock port of /A mode:

er and

emove the /24 I/O.

nch in-refully re-

s as noted wrench.

I/O.

4 I/Os chas- a set of th a remov-s controls a h is shown

the word st jumper) -pronged

7 Place it in the position corresponding to the value that you desire. For an AES/EBU word clock lock port, it should be placed over the right two prongs. For a S/PDIF word clock lock port, it should be placed over the left two prongs. Refer to Figure 1 and 2 for details.

8 After you have made the desirreplace the top of the 888/24 I/

9 Replace the four front panel sthe hex wrench.

10 Replace the top screws withscrewdriver.

Muting the DAC Outthe 888/24 I/O in AStand-Alone ModeIn certain cases, you may wish 888/24 I/Os D/A converters whstand-alone mode. This is usefuample, you need to eliminate pternal analog feedback through

To do this, you must open the and move an internal jumper sthat the DACs are muted durinalone operation.

+ Refer to Figure 1 and 2 for detaswitches and their default positio

To change the DAC output mute s888/24 I/O in stand-alone D/A

1 Make sure that your comput888/24 I/O are turned off.

2 With a Phillips screwdriver, rscrews from the top of the 888

3 Using the 1/16 inch hex wrench in-cluded with the 888/24 I/O, carefully re-move the front four panel screws as noted on the bag containing the hex wrench.

4 Lift the top off of the 888/24 I/O.

5 Inside the left-front of 888/24 I/Os chas-Using the

ed changes, O.

crews using

a Phillips

puts of /D

to mute the en in A/D l if, for ex-otential ex- a console.

888/24 I/O witch so g stand-

ils on jumper ns.

etting of the mode:

er and

emove the /24 I/O.

sis, near the large FPGA chip, isthree jumper switches, each wiable cap. Each of these switchedifferent default function as shure 1 and 2.

6 Locate the jumper switch formuting default (the middle jumgently lift the cap off the 3-pronector.

7 Place it in the position corresthe value that you desire. To mDACs, it should be placed over prongs. To unmute the DACs (aoperation), it should be placedright two prongs. Refer to Figuredetails.

8 After you have made the desirreplace the top of the 888/24 I/

9 Replace the four front panel sthe hex wrench.

10 Replace the top screws withscrewdriver. 888/24 I/O 11

a set of th a remov-s controls a own in Fig-

the DAC per) and

nged con-

ponding to ute the the left two s in normal over the 1 and 2 for

ed changes, O.

crews using

a Phillips

888/24 I/O12

appendix a

Technical Speci

General

Analog Inputs/Outputs:

n Actively balanced XLR conneoutputs internally switchable b+4 dBu and 10 dBV line levels

Analog Level Trimming:

n Accessible from front panel

Digital I/O AES/EBU:

n 8 channel; balanced XLR con

Digital I/O S/PDIF:

n 2 channel; coaxial RCA conn

Sample Rate:

44.1 kHz or 48 kHz, 10ppm

Clock Reference:

n Super Clock (256x) sample clBNC connectors; additional cloences supported via DigidesignSlave Driver, SMPTE Slave DrivSlave Driver and other optionanizers

Nominal Operating Level:

n +4dBu; factory calibrated at headroomAppendix A: Technical Specifications 13fications

ctors, etween

nectors

ectors

ock In/Out; ck refer-'s Universal er, Video l synchro-

18dB

A/D Specifications

SNR (signal-to-noise ratio):

n 113 dB (balanced, A-weigh

n 110 dB (unweighted)

THD:

n 0.003% 0.01 dB @ 1kHz; 20(band-limited)

Maximum Input Level:

n +26dB

Frequency Response:

n 1 dB, 20 Hz20 kHz

Clock jitter:

n < 40pS RMS 22Hz-22kHz BWted)

Hz-20 kHz

888/24 I/O14

D/A Specifications

SNR (signal-to-noise ratio):

n 110 dB (balanced, A-weighted)

n 107 dB (unweighted)

THD:

n 0.003% 0.01dB @ 1kHz; 20 (band-limited)

Maximum Output Level:

n +26 dB/channel (bridging loa

Frequency Response:

n 1dB, 20 Hz20 kHz

Physical Specifications

Power requirements:

n 90260 VAC, 47 63 Hz; 30 VAauto-switching

Weight:

n 7.6 lbs (4.1 kg)

Dimensions:

n 2U external rackmount devic19" x 3.5" x 9.75" (48.26 cm x 8.89 cm x 24.77 cmHz- 20 kHz

ds)

;

e

)

appendix b

Calibrating the

Before you use the 888/24/I/O face, you may want to calibrateand output levels to the level oing console.

The 888/24 I/O is factory-calibrits input operating level is set tnominal with 18 dB headroomfull code, unity gain, making cunnecessary for most professiotions.

If you do need to recalibrate yoor other components of your scan use the alignment procedurhere.

About CalibrationCalibrating levels on a digital revice is different from calibratinan analog recording device. Undevices, most digital devices dostandard 0 VU level setting tsponds to nominal input and ouInstead, with an interface such888/24 I/O, the meters are calibdecibels below peak (digital clippAppendix B: Calibrating the 888/24 I/O (Pro Tools 5.0) 15888/24 I/O (Pro Tools 5

Audio Inter- its input f your mix-

ated so that o +4 dB nominal at alibration nal applica-

ur interface tudio, you e described

cording de-g levels on like analog not have a hat corre-tput levels.

as the rated in ing) level.

HeadroomThe concept of headroom is slient for analog and digital devic

Analog Most analog devices allotain amount of headroom abovyou send a signal above the 0 Van analog recorder, you still haof headroom, and if tape saturait does so fairly gracefully, givina compressed sound that someable.

Digital Digital devices, on the odo not allow for signals that exnamic range of the input. Wheexceeds the maximum input leital device, clipping occurs, caudistortion, which is harsh and desirable.

The 888/24 I/O provides an inddard headroom of 18 dB. The eyou use will be determined by tof headroom available in the resystem. For example, if your msole has 15 dB of headroom abolevel, then you may want to ca888/24 I/O to have 15 dB of he.0)

ghtly differ-es.

w for a cer-e 0 VU. If U level to

ve a margin tion occurs, g the audio find desir-

ther hand, ceed the dy-n a signal vel for a dig-sing digital usually un-

ustry stan-xact value he amount st of your ixing con-ve nominal librate the adroom.

888/24 I/O16

The Calibration ProcessAnalog To calibrate the input level of an an-alog device to a mixing consoles output level, you would typically send a 1 kHz tone at 0 VU from the console to the ana-log deck and align the recording decks meters to read 0 VU.

Digital With a digital recording as the 888/24 I/O, however, in low for headroom, you must altone from the console to a valuzero on the 888/24 I/O, by exaamount of headroom that you

For example, to have 12 dB of habove 0 VU with the 888/24 I/Oalign the incoming 0 VU 1kHzlevel of 12 dB. For 18 dB of heyou would align it to 18 dB. (Ssumed that you are using the 8with a +4 dBu console, a 0 VU coming out of the console is actalent to a nominal +4 dBu leve

Calibrating The 888/If you are using Pro Tools 5.0 ocan put Pro Tools software in aerating mode called calibration use the Signal Generator Plug-Iate a test tone for calibration o888/24 I/O.

If you are using Pro Tools 4.3.1refer to Appendix C: Calibrating 888/24 I/O (Pro Tools 4.x) for castructions.

The Pro Tools Installer includesconfigured calibration session tthat cover most common calib

ups. You can use these in addition to the calibration procedure given below.

s Turn down your monitoring system before beginning calibration. The Signal Generator Plug-In emits a continuous signal when in-serted on a track.device such order to al-ign a 0 VU e less than

ctly the want.

eadroom , you must

tone to a adroom, ince it is as-88/24 I/O signal level ually equiv-l signal.)

24 I/O r later, you special op-mode, then n to gener-f the

or earlier, the libration in-

several pre-emplates ration set-

] During calibration, set all Pro Tfaders to their default of 0 dB by clicking (Macintosh) or Alt-Shift-cldows) on any fader in the session

To calibrate the 888/24 I/0:

1 In Pro Tools, choose Setups >and click Operation.

2 Under Output Options, selectputs.

3 At the bottom of the Operatiences dialog, enter a CalibratioLevel value (a level of 18 dB is

4 Click Done.

5 Create a new audio track andSignal Generator Plug-In on th

6 Set Signal Generators outputshould be the same value you ethe Calibration Reference Leve

7 Set Signal Generators freque1000 Hz.

8 Set Signal Generators signal wSine.

9 Route the tracks output to B

10 Create a mono auxiliary inpeach 888/24 I/O output you wabrate. Set the output assignmenthese auxiliary inputs to its res888/24 I/O output.

11 Set the input of each auxiliatrack to Bus 1.ools track Option-Shift-icking (Win-.

Preferences

Direct Out-

on Prefer-n Reference typical).

insert the e track.

level. This ntered as

l in step 3.

ncy to

aveform to

us 1.

ut track for nt to cali-t for each of pective

ry input

12 Create an additional mono auxiliary in-put track for each 888/24 I/O input you want to calibrate. Set the input assignment for each of these auxiliary inputs to its re-spective 888/24 I/O input. Then set the output of each of these auxiliary inputs to an unused bus pair (for exampleso that feedback doesnt occur itoring main outputs 12.

13 Connect an external VU meof the 888/24 I/O outputs in turtime as you calibrate.)

14 Adjust the 888/24 I/O outpupots with a Phillips screwdriveroutputs to read 0 VU on the emeter.

15 Connect each output of thedirectly to its input: Connect coutput to channel 1 input, andeach channel.

16 In Pro Tools, choose Operatbration Mode.

The names of all uncalibrated tto flash. In addition, the track vcator of each auxiliary input traan external input signal now dreference level coming from thoutput.

17 Adjust the 888/24 I/O inpupots with a Phillips screwdriverinputs to match the reference lthe level is properly matched, tname will stop flashing.

The Automatch indicator arrows on each track show the direction of adjustment re-quired for alignment:

u When the incoming level is higher than the reference level, the down arrow will ap-pear lit (blue). In this case, trim the Appendix B: Calibrating the 888/24 I/O (P

bus 3132) when mon-

ter to each n. (One at a

t level trim to align the xternal VU

888/24 I/O hannel 1 so on for

ions > Cali-

racks begin olume indi-ck receiving isplays the e calibrated

t level trim to align the evel. When he track

888/24 I/O input level down.

u When the incoming level is the reference level the up arrowlit (red). In this case, trim the 8input level up.

When you have properly aligncoming peak signal levels to mibration reference level, both Aindicator arrows will light: the uand the down arrow blue.

18 When you have finished, chations > Calibration Mode againCalibration Mode.

Calibrating a System W888/24 I/O and 882/20Audio InterfacesThe 888/24 I/O is factory presetof headroom in its +4 dB line ling mode. The 882/20 I/O, howfixed at 14 dB of headroom andare not adjustable.

When setting up an 882/20 I/Olarly in systems using a combin882/20 I/O and 888/24 I/O), mthat you use a headroom settinfor your system. This helps enscorded audio files have the samlevels regardless of which interfrecorded with.ro Tools 5.0) 17

lower than will appear 88/24 I/O

ed the in-atch the cal-utomatch p arrow red

oose Oper- to deselect

ith Both I/O

with 18 dB evel operat-ever, is its inputs

(particu-ation of the ake sure g of 14 dB ure that re-e relative

ace they are

888/24 I/O18

appendix c

Calibrating the

Before you use the 888/24/I/O face, you may want to calibrateand output levels to the level oing console.

The 888/24 I/O is factory-calibrits input operating level is set tnominal with 18 dB headroomfull code, unity gain, making cunnecessary for most professiotions.

If you do need to recalibrate yoor other components of your scan use the alignment procedurhere.

About CalibrationCalibrating levels on a digital revice is different from calibratinan analog recording device. Undevices, most digital devices dostandard 0 VU level setting tsponds to nominal input and ouInstead, with an interface such888/24 I/O, the meters are calibdecibels below peak (digital clippAppendix C: Calibrating the 888/24 I/O (Pro Tools 4.x) 19888/24 I/O (Pro Tools 4

Audio Inter- its input f your mix-

ated so that o +4 dB nominal at alibration nal applica-

ur interface tudio, you e described

cording de-g levels on like analog not have a hat corre-tput levels.

as the rated in ing) level.

HeadroomThe concept of headroom is slient for analog and digital devic

Analog Most analog devices allotain amount of headroom abovyou send a signal above the 0 Van analog recorder, you still haof headroom, and if tape saturait does so fairly gracefully, givina compressed sound that someable.

Digital Digital devices, on the odo not allow for signals that exnamic range of the input. Wheexceeds the maximum input leital device, clipping occurs, caudistortion, which is harsh and desirable.

The 888/24 I/O provides an inddard headroom of 18 dB. The eyou use will be determined by tof headroom available in the resystem. For example, if your msole has 15 dB of headroom abolevel, then you may want to ca888/24 I/O to have 15 dB of he.x)

ghtly differ-es.

w for a cer-e 0 VU. If U level to

ve a margin tion occurs, g the audio find desir-

ther hand, ceed the dy-n a signal vel for a dig-sing digital usually un-

ustry stan-xact value he amount st of your ixing con-ve nominal librate the adroom.

888/24 I/O20

The Calibration ProcessAnalog To calibrate the input level of an an-alog device to a mixing consoles output level, you would typically send a 1 kHz tone at 0 VU from the console to the ana-log deck and align the recording decks meters to read 0 VU.

Digital With a digital recording as the 888/24 I/O, however, in low for headroom, you must altone from the console to a valuzero on the 888/24 I/O, by exaamount of headroom that you

For example, to have 12 dB of habove 0 VU with the 888/24 I/Oalign the incoming 0 VU 1kHzlevel of 12 dB. For 18 dB of heyou would align it to 18 dB. (Ssumed that you are using the 8with a +4 dBu console, a 0 VU coming out of the console is actalent to a nominal +4 dBu leve

Calibrating The 888/If you are using Pro Tools 4.3.1you can use the Calibration Totion (available on your Pro TooCD-ROM) to calibrate the outpputs of the 888/24 I//O.

If you are using Pro Tools 5.0 oto Appendix B: Calibrating the 88(Pro Tools 5.0) for calibration indevice such order to al-ign a 0 VU e less than

ctly the want.

eadroom , you must

tone to a adroom, ince it is as-88/24 I/O signal level ually equiv-l signal.)

24 I/O or earlier, ol applica-ls Installer uts and in-

r later, refer 8/24 I/O structions.

The Calibration Tool software

The Calibration Tool has the focontrols:

Channel Use this pop-up to selechannel for the input level read

Input Level Use this as a graphicmerical display of the dB level the headroom you have specifiparticular interface. (In other wamount of dB below digital clipamount of analog headroom yuse in your system.)

Signal Present This indicates w60 dB signal relative to the hepresent at the input.

Headroom Use this field to enterof headroom between your 0 dthe 888/24 I/O full scale digitalvalues above the full scale digitacause digital clipping.

Oscillator Use this to turn the aform generator on or off.

Frequency Click on this pop-upthe output frequency of the auform generator. You can choos1 kHz, or 10 kHz signal.llowing

ct the input ings.

and nu-relative to ed on that ords, the ping, or the ou wish to

hen a adroom is

an amount B level and value. Any l value will

udio wave-

to select dio wave-e a 100 Hz,

Level Use this to select the output level rel-ative to the Headroom for the audio wave-form generator.

Wave Type Use this to select the type of au-dio waveform generated the waveform generator.

Output Every Channel If this optlected and the Oscillator is on,put will generate an audio waveat the selected frequency. If thinot selected and the Oscillatorthe selected output Channel wthe audio waveform signal. If this off, this option has no effect

Hardware Setup Use this to choDigidesign audio interface andwish to adjust using Calibratio

In order to align your system wware, you must have one of th

u A device (such as sine wave ogenerator) that can send a 1 kHwaveform wave into the 888/20 VU.

or

u A device (such as a mixing coaccurate VU meters) that can mlevel of a 1kHz audio waveformby the 888/24 I/O.

Using an External ToneGeneratorIf you have a sine wave generatproduce a 0 VU 1 kHz tone, useing calibration procedure:

To calibrate the 888/24 I/O withTool using an external source:

1 Start the Calibration Tool ap

2 In the Headroom field, enter the amount of headroom you desire. The default setting for the 888/24 I/O is 18 dB.

3 Send a 1kHz tone into the 888/24 I/O from your external source.

4 In the software, select 888/24 I/O 1 Appendix C: Calibrating the 888/24 I/O (P

ion is se- every out-form signal s option is is on, only ill generate e Oscillator .

ose which card you n Tool.

ith this soft-e following:

r test tone z audio

4 I/O at

nsole with easure the produced

or that can the follow-

Calibration

plication.

Channel 1 from the Channel pmenu. You should get some levscreen level meter.

5 Adjust the 888/24 I/O ChannLevel trim pot by inserting a scinto the Input Level trim pot anuntil the Calibration Tools on-meter reaches 0 VU and the nuout says 0.0 dB. The input is no

6 Repeat this procedure for eac888/24 I/O input by selecting tthe Channel pop-up menu andthe appropriate front panel Inptrim pot on the 888/24 I/O.

7 When you have finished aligputs, connect each output of th888/24 I/O directly to its inputChannel 1 output to Channel 1so on.

8 Select 1kHz from the oscillatquency pop-up menu, and turntor on by clicking On.

9 Choose 888/24 I/O 1 Channthe Channel pop-up. Adjust thLevel trim pots by inserting thescrewdriver into the pot and tutil the on-screen meter reachesthe numeric readout says 0.0 d

10 Repeat this procedure for eacterface output.ro Tools 4.x) 21

op-up el in the on-

el 1 Input rewdriver d turning it screen meric read-w aligned.

h hem from adjusting ut Level

ning the in-e

: Connect input, and

or Fre- the oscilla-

el 1 from e Output Phillips rning it un- 0 VU and B.

h Audio In-

888/24 I/O22

Using a VU meter If you don't have a sine wave generator or another way to send a 1 kHz tone into the 888/24 I/O at 0 VU, a second alternative is to measure the output level of the 888/24 I/O with a VU meter, such as the kind found on a professional-qing console. To do this, be sureoutputs of the 888/24 I/O are cothe VU meters of the console ovice. (On most consoles these iusually the tape returns, or posline inputs.)

To calibrate the 888/24 I/O withTool using an external VU meter

1 In the Calibration Tool softwkHz from the Frequency pop-upclick the oscillator setting to O

2 Adjust the 888/24 I/O Outpupots with a Phillips screwdriveroutputs to read 0 VU on youmeters.

3 After you have done this, cooutput of the 888/24 I/O directput: Connect Channel 1 OutpuChannel 1 Input, and so on fornel.

4 To align the inputs, select 88Channel 1 from the Channel pmenu. Adjust the 888/24 I/O Intrim pot with the screwdriver uscreen meter reaches 0 VU. Tnow aligned.

5 Repeat this procedure for eacuality mix- that the nnected to

r other de-nputs are sibly the

Calibration :

are, select 1 menu and

n.

t Level trim to align the r console's

nnect each ly to its in-t to each chan-

8/24 I/O 1 op-up put Level ntil the on-his input is

h input.

Using the 888/24 I/OThe 888/24I/O Interface888/24I/O Front Panel1. Power2. Sync Mode3. Sample Rate and 12 Format Indicators4. Level Meters5. Input Level Trims6. Output Level Trims

888/24I/O Back Panel1. Analog Audio Outputs2. Analog Audio Inputs3. AES/EBU Digital Outputs 184. AES/EBU Digital Inputs 185. 50-pin Interface Connector6. S/PDIF Digital Input/Output7/9. Slave Clock In/Out8. Power Input

Changing Operating Levels of Individual 888/24I/O ChannelsMaking Signal Connections to the 888/24I/OChoosing between +4dBu and 10dBV operation modesSetting Up Your Studio

Using the 888/24I/O Interface as Stand-Alone Audio ConverterChanging the Default Sample Rate of the 888/24I/O in A/D Stand- Alone ModeChanging the Default Word Clock Lock Port of the 888/24I/O in D/A Stand- Alone ModeMuting the DAC Outputs of the 888/24I/O in A/D Stand-Alone Mode

Technical SpecificationsGeneralA/D SpecificationsD/A SpecificationsPhysical Specifications

Calibrating the 888/24I/O (ProTools 5.0)About CalibrationHeadroomThe Calibration Process

Calibrating The 888/24I/OCalibrating a System With Both 888/24I/O and 882/20I/O Audio Interfaces

Calibrating the 888/24I/O (ProTools 4.x)About CalibrationHeadroomThe Calibration Process

Calibrating The 888/24I/OUsing an External Tone GeneratorUsing a VU meter