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DigiPro DA795
Operation Manual
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Sencore DigiPro DA795 Operation Manual

DA795
DigiPro
Digital Audio Analyzer
Operation Manual
(Firmware version 1.17)
3200 Sencore Drive, Sioux Falls, SD 57107
http://www.sencore.com mailto:sales@sencore.com 1.800.736.2673 or 1.605.339.0100
WARNING
PLEASE OBSERVE THESE SAFETY PRECAUTIONS
There is always a danger present when using electronic test equipment.
Unexpected voltages can be present at unusual locations in defective
equipment and distribution systems. Become familiar with the equipment
with which you are working, and observe the following safety precautions.
Every precaution has been taken in the design of the DigiPro DA795 Digital Audio Analyzer to insure that it is as safe as possible. However, safe operation depends on you, the operator.
1. Never exceed the limits of the DigiPro DA795 as given in the specifications
section or other special warnings provided in this manual.
2. Always be sure that your equipment is in good working order. Broken or
frayed test leads or cables can be extremely dangerous and may expose you to high voltages.
3. Remove test leads immediately following measurements to reduce the
possibility of shock.
4. Do not work alone when working under hazardous conditions. Always have
another person available in case of an accident.
5. Never assume that a cable shield is at earth ground potential. Both static
and electrical voltages can be present on a cable’s sheath.
6. Always follow standard safety procedures.
When in doubt, be careful.
Sencore reserves the right to make changes in specifications and other information contained in this publication without prior notice, and the reader should in all cases consult Sencore to determine whether any such changes have been made. This manual may not be reproduced, and is intended for the exclusive use of Sencore users.
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DA795
DigiPro
Digital Audio Analyzer
Operation Manual
(Firmware version 1.17)
3200 Sencore Drive, Sioux Falls, SD 57107
iii
TABLE OF CONTENTS
SAFETY PRECAUTIONS ...................................................................... inside front cover
DESCRIPTION................................................................................................................ 1
Introduction ............................................................................................................................1
Features.................................................................................................................................2
Specifications .........................................................................................................................4
Accessories............................................................................................................................6
I/O CONNECTIONS........................................................................................................ 7
Input Panel (Bottom when viewing display) .......................................................................7
Digital Input 1.....................................................................................................................7
Digital Input 2.....................................................................................................................7
Power Adapter Input Jack..................................................................................................7
Power Switch.....................................................................................................................7
Battery Compartment.........................................................................................................7
Output Panel (Top when viewing display) ..........................................................................8
Digital Audio Outputs .........................................................................................................8
Analog Audio Outputs........................................................................................................8
Word Clock In / Video Input ...............................................................................................8
DB-9 Connector.................................................................................................................8
LCD Contrast.....................................................................................................................8
Speaker.............................................................................................................................8
Battery Module Information .................................................................................................9
Battery Module Introduction ...............................................................................................9
Charging............................................................................................................................9
Automatic Power Switch ....................................................................................................9
Battery Life & Charging Times ...........................................................................................9
Clocks & Routing ...............................................................................................................10
Master Clock....................................................................................................................10
Output Clocking ...............................................................................................................10
USER INTERFACE....................................................................................................... 11
User Interface Features......................................................................................................11
Control Knob Operation ...................................................................................................11
Menus..............................................................................................................................11
Saving Preferred Settings................................................................................................12
Top Toolbar ........................................................................................................................12
Function Control and Information.....................................................................................12
Input Control and Information...........................................................................................12
Bottom Toolbar...................................................................................................................13
Analog Output Control .....................................................................................................13
Digital Output and Generator Control...............................................................................14
ANALYSIS FUNCTIONS MENU................................................................................... 16
Bitstream Analyzer ...............................................................................................................17
Digital Watchdog ..................................................................................................................20
Clock/Sample Counter..........................................................................................................22
Bitscope ...............................................................................................................................23
Distortion Meter....................................................................................................................25
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DIGITAL TESTS MENU................................................................................................ 27
Digital Lock Test...................................................................................................................28
Video Lock Test....................................................................................................................30
Transparency Test ...............................................................................................................32
Latency Test.........................................................................................................................34
Jitter Meter...........................................................................................................................36
SYSTEM TOOLS MENU............................................................................................... 38
Level Meter ..........................................................................................................................39
LAeq Dialog Level ................................................................................................................41
Signal Generator ..................................................................................................................42
Sweeps ................................................................................................................................44
Pass Mode ...........................................................................................................................47
UTILITIES MENU.......................................................................................................... 49
Digital Cable Tester..............................................................................................................50
Capture Sample Data...........................................................................................................51
Save Defaults.......................................................................................................................53
About....................................................................................................................................54
GLOSSARY .................................................................................................................. 55
WARRANTY & SERVICE INFORMATION............................................inside back cover
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DESCRIPTION
Introduction
The DigiPro Digital Audio Analyzer is a multi-function, dual-domain precision digital audio test instrument.
The DigiPro provides a powerful, complete set of test, troubleshooting and utility functions for digital audio analysis, in a hand-held DSP-powered device.
The DigiPro allows you to analyze any professional or consumer format stereo digital audio signal, and generate low-noise digital test signals, all at up to 24-bit/96k-sample rate resolution. Digital audio analysis features and functionality, normally found only on expensive bench test equipment, are now available in a portable, easy-to-use and cost-effective package.
The DigiPro features a Transparency Test, Bit-Stream Analyzer, Lock Test, Bit-Scope, Latency Test, Digital Watchdog, Jitter Meter, Clock/Sample Counter, Distortion Meter, and more!
The DigiPro provides all the connections you’ll need; two sets of AES/EBU and SP/DIF inputs, including Toslink and ADAT, plus Word Clock in. Digital outputs include AES/EBU, SP/DIF, and Toslink/ADAT, and Word Clock out. Analog stereo headphone and unbalanced mono analog outputs provide for testing of dual-domain devices, such as analog to digital converters (ADCs) or digital mixing consoles. Also included are ADAT sync and RS-232 serial for computer interfacing.
Multi-Tasking
The DigiPro has independent input, output, and monitor sections. This allows simultaneous analysis, signal generation, and analog headphone monitor.
Multi-Function
The DigiPro Digital Audio Analyzer employs a powerful DSP engine. All functions, filters, and processing are implemented in DSP firmware algorithms. As each function is loaded into internal memory and executed, the DigiPro takes on a completely new personality.
Precision Test & Measurement
The DA795 DigiPro digital analyzing and generator functions, with digital inputs, digital outputs, and analog outputs, provide an integrated level of dual-domain test and troubleshooting efficiency that smple digital monitoring devices can’t begin to offer. This allows you to easily test digital signal integrity , check for digital equipment compatibility, and check for status information that doesn’t match the audio data.
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Features
Bitstream Analyzer- Totally analyzes digital audio stream characteristics, checking header
status bytes, plus actual word length and sample rate, bit activity, and low voltage.
Digital Watchdog - Captures signal errors for a test period and graphs the errors.
Clock / Sample Counter - Measures the actual digital sample rate, word clock, and superclock
frequencies for a digital audio signal.
Bitscope - Shows distortion, noise or jitter on an S/D or X-Y scope, and also applies the results
to the internal speaker, headphones, and line output.
Distortion Meter - Measures THD+N (Total Harmonic Distortion & Noise)
Digital Lock Test - Tests whether a digital audio input (AES/EBU or S/PDIF format) is locked
to another digital audio input, word clock, superclock, ADAT input, or ADAT sync (to <1ppm).
Video Lock Test – Tests whether a digital audio signal in AES/EBU, S/PDIF, or ADAT format
is locked (to <1ppm) with a video sync signal (black burst).
Transparency Test - Verifies that a device passes digital test waveforms without errors, using
either synchronous or asynchronous test. Any modification of the digital data stream will be detected.
Latency Test - Checks the amount of signal delay through a device with a digital device input,
and either a digital or analog device output.
Jitter Meter - Tests RMS interface jitter on a digital signal (to 150ps) or clock (to 35ps), as
referenced to an internal crystal or external master clock.
Level Meter - Monitors the level of a digital source signal. Numeric, VU (volume units), and
PPM (peak program meter) meters are available.
LAeq Dialog Level - LAeq refers to the "equivalent" average sound level, measured using A-
weighting which is most sensitive to speech intelligibility frequencies of the human ear. LAeq is prescribed in the AC-3 DTV audio standard as the proper means to set the "dialnorm" value, which sets the volume of dialog in every consumer DTV receiver.
Signal Generator - Creates standard digital audio test signals with sine, square, white, and pink
waveforms.
Sweeps – Provides both amplitude and sine sweep modes. Amplitude sweep generates a swept sine wave, outputs it to both the analog and digital outputs,
and measures the incoming digital audio signal level. Results are plotted on the screen.
Sine sweep generates a swept sine wave, between two selected end frequencies, and repeats the
sweep until turned off.
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Pass Mode – Passes a digital input signal through to the output with any selected modifications.
Possible signal modifications include changing header information, performing sample-rate conversion (from 44.1 kHz to 96 kHz), changing signal formats (AES/SPDIF/ADAT), adding digital gain or attenuating the signal.
Digital Cable Tester - Tests digital audio cables for functional quality. Provides a method of
comparing digital audio cables.
Capture Sample Data - Captures a buffer of data from the AES or SP/DIF input, and then
allows you to step through the buffer to examine the data, or search for particular values.
Digital Monitor - Allows you to hear a digital signal with headphones or built-in speaker.
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Specifications
Digital Input/Output
Digital Signal Formats
AES-3 S/PDIF coaxial S/PDIF optical (Toslink) ADAT BNC
Lock Detect
Lock detect: <1 ppm.
Digital Watchdog
Minimum Test Period: 1 minute Maximum Test Period: 24 hours Minimum length of detected error, all test times: 1 sample
Transparency Test
Maximum number of errors per channel: 65,536. Maximum length of test: unlimited.
Frequency Counter
Signal Generator
Latency Test
Jitter Meter
Analog Output
Frequency Accuracy: 0.1 ppm, or ±0.01 Hz in a word clock or sample clock, or ±4 Hz in a master clock signal (256xFs).
Sine wave output frequency: 1 Hz to 20 kHz Sine wave distortion: Better than –130 dB THD+N
Accuracy: ±2 samples
Jitter Range
AES/EBU or S/PDIF Input: 150 ps to 100 ns Clock/Super clock Input: 35 ps to 100 ns
Jitter Accuracy: greater of ±5% of reading or ±10ps
Output voltage range:
Unbalanced: 0 dBu to –66 dBu
Balanced: +6 dBu to –60 dBu Output voltage accuracy: ±1 dB Sine wave distortion: Better than –85 dB THD+N
Standards
AES-3 VU/PPM: DIN 45406 (IEC 60268)
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General/Environmental
Input Impedances
XLR digital inputs: 110 kohms, nominal S/PDIF digital inputs: 75 kohms, nominal BNC Word Clock/Video input: 75 kohms, nominal
Output Impedances
XLR digital output: 110 ohms, nominal S/PDIF digital output: 75 ohms, nominal Word Clock digital output: 75 ohms, nominal ¼” Stereo Headphone analog output: 5 ohms, nominal RCA phono unbalanced analog output: 110 ohms, nominal
Display: 64x128 pixel blue LCD with backlight Size: 5 1/2" x 12 1/2" x 2 1/4" (HWD) Weight: 4.5 lbs.
Temperature Range
5°C to 45°C, non-condensing
Power
Battery: Sealed Lead Acid 6 Vdc module. AC adapter/charger: 100-240 Vac, 47-63 Hz, 7.5 Vdc, 4 A
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Accessories
DA795 Digital Audio Analyzer Accessories
Sencore Part #s
13G122
13G124
17G46
60G81
Description Photo
XLR Audio Cable – a 12 ft. microphone cable for interfacing balanced audio inputs and outputs to the DA795.
supplied
Serial Interface Adapter Cable – a
6’ computer serial interface adapter cable (straight through), connects between the unit’s RS232 jack and a computer serial port.
supplied
Sealed Lead Acid Battery Module
– 6 volts
supplied
AC Power Adapter/ Charger 7.5
VDC, 4A - plugs into the DA795 to charge the battery or to provide AC operation.
supplied
Battery not pictured
Soft Carry Case padded carrying case to transport unit; includes extra
10B897
storage capacity for supplied accessories.
supplied
http://www.sencore.com mailto:sales@sencore.com 1.800.736.2673
Specifications and accessories subject to change without notice.
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I/O Connections
Input Panel
(Bottom – when viewing display)
Digital Input 1
Digital Input 1 connectors include an AES/EBU input, the S/PDIF input, and an optical input connector, which supports both ADAT and S/PDIF (Toslink) format. These inputs are selectable within most DigiPro functions. Note that the S/PDIF and Toslink inputs share circuitry, so only one of the inputs should be used at a time.
Digital Input 2
Digital Input 2 connectors include one AES/EBU input and one S/PDIF input. These inputs are selectable within the Digital Lock Test, Jitter Meter, and the Digital Cable Tester functions. The actual digital audio data is not decoded from these inputs. The Digital Input 2 signal is used only for timing, jitter, and lock measurements.
Power Adapter Input Jack
The power input powers the DigiPro and charges the battery when the DigiPro is switched off. Using an incorrect power adapter can damage the battery, battery charger, and/or the DigiPro. The Digital Audio Analyzer requires 7.5 Vdc unregulated at a minimum of 800ma. The input connector is a 2.1mm coaxial power connector, positive on the center pin.
Power Switch
The power switch is mounted on the DigiPro input panel, and switches the DigiPro on or off when it is powered by the internal battery or the AC power adapter.
Battery Compartment
The Digital Audio Analyzer includes an internal rechargeable sealed lead acid (SLA) battery. The battery can be accessed by unscrewing the thumbscrew and opening the battery compartment door on the front of the unit. The battery is removable by sliding the battery module out of the DigiPro and disconnecting the circuit board.
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Output Panel (Top – when viewing display)
Digital Audio Outputs
Digital output connectors include an AES/EBU output, S/PDIF coaxial output, ADAT/Toslink optical output, and a Word Clock Output. The ADAT output sends out a copy of the stereo digital audio data on all four ADAT stereo pairs. The Word Clock output is derived from the output digital audio transmitter, and so follows the lock source selected for the generator.
Analog Audio Outputs
Analog output connectors include an unbalanced RCA phono output and a 1/4” TRS (tip, ring, sleeve) output that can be configured as a stereo output (suitable for headphones) or as a balanced mono output. The analog outputs monitor the digital input, or provide an analog copy of the digital output. (See the Top Toolbar section of this manual.)
Word Clock In / Video Input
The Word Clock In (BNC connector) is used to lock the DA795 to an external clock, and also as an input to the jitter/lock tester board, as a 256xFs sample clock. The DigiPro digital output can be locked to this source, if desired. Also, this connector can be selected by the Clock/Sample Counter function, to measure the frequency of the signal. This connector also functions as a video input for the Video Lock Test function, for testing lock between a video sync signal (black burst or other video signal) and an AES, S/PDIF, Toslink, or ADAT digital audio signal.
DB-9 Connector
This connector is used both as a serial RS-232 interface port and as an ADAT sync input port. The ADAT sync signal is a word clock signal on pin 8 of this connector, and does not interfere with RS-232 communications, which uses pins 2, 3, and 5 on the DA795. The ADAT Sync input and the Word Clock Input share circuitry, so only one of these inputs should be used at a time.
LCD Contrast
Use this control to adjust the contrast of the blue super-twist LCD display for optimum viewing.
Speaker
The speaker outputs a mixed left and right channel audio that can be switched on or off independently of the analog line outputs. However, if the main analog output is switched off, the speaker audio is also off. The internal speaker may be used for monitoring digital signals when headphones are not available or convenient.
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Battery Module Information
Battery Module Introduction
The battery module consists of a battery with a battery charger board mounted directly on the battery. It has two coaxial power connectors mounted on it, one that accepts the AC power adapter plug, and one that mates with the DigiPro internally. These connectors are different sizes so that the power plug cannot be plugged into the wrong connector. Also, the battery module cannot be inserted the wrong way.
Charging
Anytime the AC power adapter is plugged into the battery module, the battery will be charging. You cannot overcharge the battery. It is best to leave the AC power adapter plugged into the battery module whenever possible. When the battery is mounted in the DigiPro, and the DigiPro is switched on, the battery charges very slowly, since most of the power from the AC power adapter is being used to run the DigiPro. You can charge the battery either in the DigiPro, or with the battery module removed. If you have a spare battery module, you can charge one battery module with the AC power adapter while you operate the DigiPro with the other, charged, battery module.
Automatic Power Switch
The battery module uses an automatic relay to switch from AC to battery power, and to prevent the SLA battery from being completely discharged, which can damage it. The switchover happens automatically as the AC power adapter is plugged into the battery module. In some cases, it is possible to latch the relay into a state in which the battery, even though it is charged, will not operate the DigiPro. These conditions include plugging the AC power adapter into the battery module with no or very low AC power present, and extreme physical shock. To correct this condit io n, just remove the AC power adapter plug from the battery module, make sure the AC power adapter is getting good power, and plug it back into the battery module.
Battery Life & Charging Times
The display backlight is always on, since the blue LCD is not visible without the backlight.
Battery Life Charge Time DA795 On 1.1 hours 7.0 hours DA795 Off (or battery removed) 3.0 hours
Warning: Storing the DigiPro for long periods of time with a discharged battery can shorten the life of the battery, or possibly destroy the battery. The battery should be kept charged at all times, and cannot be overcharged, so it is best to leave it the power adapter plugged into the battery connector when the DigiPro is not in use.
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Clocks & Signal Routing
Digital audio equipment locks an oscillator to an incoming digital audio signal, clock, super­clock or sync signal. The DA795’s internal receiver (Master Oscillator) may be locked to an internal clock (a crystal), or an external input signal which can come from various input signal sources. Input sources include a word clock, an AES or S/PDIF signal, an ADAT sync signal, or from a super clock signal. This provides maximum versatility when analyzing digital audio signals with the DA795.
Master Clock
The DA795’s Master Clock is an internal clock that runs at 256 or 512 times the sample rate (word clock). It is used to clock the digital output and the internal analog-to-digital converter (ADC). The possible locking sources for the Master Clock are:
x Internal 32 kHz crystal
x Internal 44.1/88.2 kHz crystal
x Internal 48k/96 kHz crystal
x Recovered master clock from the digital input receiver
x External word clock, after running through the PLL at 256 times the sample rate
x ADAT recovered clock from the ADAT receiver circuit.
x ADAT Sync, after running through the PLL at 256 times the sample rate
None of the ADC derived features of the DA795 are available when the Master Clock is not locked. These include the battery level/AC indicator, Digital Lock Test, Video Lock Test, Jitter Meter, Level Meter, and the Digital Cable Tester. The Master Clock lock source is selected at the right end of the Bottom Toolbar. The frequency of this clock is always being counted, and if it is running at a frequency that is too slow to be considered valid, the locking source selection field will blink. A valid Master Clock can always be obtained by selecting any of the DA795’s internal crystals such as “Int 48 k” as indicated in the bottom right toolbar field.
Output Clocking
The DA795 can operate in one of two output modes: (1) Generator output mode or (2) Pass­through mode. In a generator mode, the internal generator creates a test signal and sends it to the digital output. In a pass-through mode (Pass Mode function only), the DA795 sends the input signal to the output, possibly with modifications. In either case, you need to select a valid lock source for the digital output, using the Bottom Toolbar.
There are times when may you want to re-clock a digital signal to match a different sample rate. The Sample Rate Converter (SRC) in the DigiPro Pass Mode function can convert an input signal at any supported sample rate (32 kHz to 96 kHz) to an output signal at any other supported sample rate (32 kHz to 96 kHz).
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User Interface
User Interface Features
The DA795 has many functions, features, and options. To make it easier to use the functions, commonly used control fields are located in the Top Toolbar and Bottom Toolbar, and are the same on most screens. Once you learn how to operate one function, you will have an easier time using the next one. The following sections discuss common user interface features.
Control Knob Operation
The Control Knob is used like a mouse on a computer. It provides a means of navigating the screens, selecting values, and changing the contents of control fields. To move around the menus, or the fields in a function, just turn the Control Knob clockwise or counterclockwise. The moves the control focus (highlight) around the screen. With the focus on a menu item or control field, clicking the Control Knob does one of three things:
1. Selects the choice (as on a menu)
2. Changes the option in a control field (if there are only a few choices, like on and off)
3. “Locks” the cursor to allow you to turn the Control Knob and change the value of a control field. Turning the Control Knob clockwise increases the value, counterclockwise decreases the value.
Figure 1
Menus
When you initially power up the DA795, after the initialization screen you will see the main menu screen. It has four menu items (Fig. 1). Clicking on one of these menu items displays a second menu which includes a list of named functions. Clicking on one of these function names starts the selected function. To exit a function, or to move from a function list to the main menu, just click on the Back character (< ) in the upper left corner (Fig. 2).
Figure 2
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Saving Preferred Settings
Many DA795 functions have control fields that you might want to have default to the same setting every time you turn the unit on. The following control fields can have their current setting saved as their default value: digital input source, sub-menu choices on all of the functions, and generator settings, including lock source, word length, frequency, and level. To store the current settings so that the DA795 will start up next time set this way, set up the DA795 the way that you want it, go to the Setup & Calibration function on the Utilities menu, and select “Save” on the Save Defaults screen. The next time you power up the DA795, your selections will be restored as the default settings.
Top Toolbar
The top line on every function screen has control fields that are used to identify and control the function and select inputs.
Function Control and Information Input Control and Information
Exit Arro
Battery Indicator Screen Title
Function Name
Input Lock
Input Select
Input Sample Rate
Input Level Meter
Function Control and Information
These items are on the left side of the Top Toolbar. x Exit Arrow. The exit arrow in the upper left corner of the screen exits the function and returns
you to the menus when you click on it. (see Figure 2)
x Battery Indicator. This field shows the relative battery level, or remaining charge in the
battery, when operating on the internal battery. When operating with the AC power adapter, this field shows the AC power symbol.
x Function Name. The name of the function currently running is shown in a box. The control
focus cannot highlight this field.
x Screen Title. Some functions have more than one function screen available. This field will
display the title for the active function screen. If you can move the control focus to highlight this field, you can click here to select the other screens.
Input Control and Information
These items are on the right side of the Top Toolbar. They are shown for all functions that use Digital Input 1 for the input signal source.
x Input Lock. The lock icon (padlock) will be open (unlocked) if no input lock is detected, or
closed (locked) if input lock is detected for the currently selected input. Clicking on this lock icon will take you to the Bitstream Analyzer screen, to get more information about the input signal.
x Input Select. The Digital Lock Test, Jitter Meter, and the Digital Cable Tester functions
receive input from Digital Input 2. For the other functions, the sources will be from Digital Input 1: AES, SPDIF/Toslink, or any of the four ADAT pairs. If you select SPDIF/Toslink, be sure that only one of those inputs is connected at a time, to prevent conflicts.
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x Input Sample Rate. This field displays the measured sample rate of the digital input signal,
with a resolution of 0.1 kHz. Note that this is the actual running sample rate, not just a reporting of the signal status bytes. This sample rate is computed by the digital receiver circuit DSP, so if the sample rate converter is running, you will see the letters “SRC” rather than a frequency. This is because the incoming frequency is being sample-rate converted within the receiver circuit, before the DSP; thus, the incoming frequency is not known to the DSP. If no valid digital input signal is detected, this field indicates “n/a.”
x Input Level Meter. The far right end of the Top Toolbar displays the digital level of the input
signal, with a 7-segment bar graph. The bar graph consists of two vertical lines, for the left and right channel levels. Each dot represents approximately 6 dB. When all seven segments are lighted, the digital input level is 0 dB FS.
Bottom Toolbar
The bottom line on every function screen has control fields that are used to control the analog outputs and the digital generator (The Latency Test doesn’t need nor display all of the Toolbar controls).
Analog Output Control Digital Output and Generator Control
Analog Output Control
The control fields for the analog output section are on the left side of the Bottom Toolbar.
x Output Type. This control field changes the 1/4” Headphone connector from
a stereo headphone output to a balanced mono output. Select Headphone to use the Toolbox as a high-quality analog headphone amplifier with integral DAC. Select Balanced (XLR) when you need a balanced analog output, for example for a generator output.
x Analog On/Off. The 1/0 icon switches all the analog audio outputs on or off
(including the speaker).
x Analog Output Level. This level gauge icon controls the analog output level.
Every rotating click of the Control Knob changes the output level by approximately 1 dB.
x Speaker On/Off. This field switches only the speaker on or off. The speaker
has its own amplifier, and can be switched off independently from the other analog outputs. To enable the speaker output, both the Analog On/Off and the Speaker On/Off fields must be switched on.
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x Analog Output Source. This field switches between Monitor and Generator for
the analog output. M selects the digital input for monitoring; G selects the internal generator (or whatever digital output signal is present). Switching from Monitor to Generator changes the source data for the DAC from the input
digital receiver circuit to the output digital transmitter. Therefore, in Monitor mode you will hear exactly what is being received, as selected by the input select field on the top toolbar, and in Generator mode, an exact copy of the digital output signal will be routed to the DAC. In either case, a valid clock source is required. For example, if G is selected, and the output clock select is flashing, there will be no analog output. Likewise, if M is selected, a valid input signal is required.
Headphone Warning: Be careful when wearing headphones and changing sample rates, analog monitor source, or input connections. Although the analog output is muted in most situations that may cause high analog levels, it is not always possible. We recommend that you remove headphones before switching any clocks, or changing functions, until a stable clock and lock has been established, and the DigiPro has had a chance to regain control of the analog outputs.
Digital Output and Generator Control
The control fields for the digital output and generator are on the right side of the Bottom Toolbar. Some fields control only the digital generator, while other fields control aspects of the digital output, whether the output source is the generator or another source, such as a digital input.
x Generator Jump. The sine icon jumps to the Generator function
screen for more output control options, such as frequency and waveform selection.
x Digital On/Off. The 1/0 icon switches the digital audio outputs on or
off.
x Digital Output Level. This level gauge icon controls the digital
generator output level. Every rotating click of the Control Knob changes the output level by exactly 1 dB.
x Word Length. This number field controls the word length (bit depth)
of the digital output. You can select any word length from 8 to 24 bits.
x Output Lock Source. This control field selects the lock source
(master clock) used for the digital output. You can select any of the five internal crystals (32 kHz to 96 kHz), the Word Clock input, the AES or S/PDIF input, the ADAT optical input, or the Super clock. The
14
ADAT sync connector (pin 8 of the DB-9 connector) and the Word Clock BNC input share the same input line. To use the ADAT sync connector (DB-9 connector, pin 8), select the Word Clock input and remove any connectors from it. Likewise, when using the Word Clock input, do not connect an ADAT sync connector. Note that if you select a lock source with no input signal, there will be no digital output. In this case, the Lock Source select field will blink. Also, since the ADC is driven by the output clock, the Battery Indicator, Jitter Meter function, and Input Level Meter will not function.
x Lightpipe Format. The A/T icon selects the output format for the optical output
connector. A selects ADAT format; T selects Toslink. Note that in ADAT format, the digital stereo output signal is copied to all four sets of ADAT stereo pairs.
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