Sencore DigiPro DA795 User manual

http://www.sencore.com mailto:[e-mail] 1.800.736.2673 or 1.605.339.0100
DA795
DigiPro
Digital Audio Analyzer
Operation Manual
(Firmware version 1.17)
3200 Sencore Drive, Sioux Falls, SD 57107

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
ii
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.
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.
When in doubt, be careful.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
iii
DA795
DigiPro
Digital Audio Analyzer
Operation Manual
(Firmware version 1.17)
3200 Sencore Drive, Sioux Falls, SD 57107

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
iv
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

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
v
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

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
1
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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
2
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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
3
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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
4
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
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).
Signal Generator
Sine wave output frequency: 1 Hz to 20 kHz
Sine wave distortion: Better than –130 dB THD+N
Latency Test
Accuracy: ±2 samples
Jitter Meter
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
Analog Output
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)

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
5
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

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
6
Accessories
DA795 Digital Audio Analyzer Accessories
Sencore
Part #s Description Photo
13G122
XLR Audio Cable – a 12 ft.
microphone cable for interfacing
balanced audio inputs and outputs to
the DA795.
supplied
13G124
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
17G46
Sealed Lead Acid Battery Module
– 6 volts
supplied
Battery not pictured
60G81
AC Power Adapter/ Charger 7.5
VDC, 4A - plugs into the DA795 to
charge the battery or to provide AC
operation.
supplied
10B897
Soft Carry Case padded carrying
case to transport unit; includes extra
storage capacity for supplied
accessories.
supplied
http://www.sencore.com mailto:[e-mail] 1.800.736.2673
Specifications and accessories subject to change without notice.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
7
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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
8
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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
9
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 condition, 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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
10
Clocks & Signal Routing
Digital audio equipment locks an oscillator to an incoming digital audio signal, clock, super-
clock 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:
xInternal 32 kHz crystal
xInternal 44.1/88.2 kHz crystal
xInternal 48k/96 kHz crystal
xRecovered master clock from the digital input receiver
xExternal word clock, after running through the PLL at 256 times the sample rate
xADAT recovered clock from the ADAT receiver circuit.
xADAT 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) Pass-
through 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).

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
11
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

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
12
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
Function Control and Information
These items are on the left side of the Top Toolbar.
xExit 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)
xBattery 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.
xFunction Name. The name of the function currently running is shown in a box. The control
focus cannot highlight this field.
xScreen 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.
xInput 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.
xInput 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.
Exit Arro
w
Function Name
Battery Indicator Screen Title
Input Lock
Input Select
Input Sample Rate
Input Level Meter

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
13
xInput 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.”
xInput 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.
xOutput 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.
xAnalog On/Off. The 1/0 icon switches all the analog audio outputs on or off
(including the speaker).
xAnalog 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.
xSpeaker 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.

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
14
xAnalog 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.
xGenerator Jump. The sine icon jumps to the Generator function
screen for more output control options, such as frequency and
waveform selection.
xDigital On/Off. The 1/0 icon switches the digital audio outputs on or
off.
xDigital 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.
xWord 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.
xOutput 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

DA795 DigiPro Digital Audio Analyzer Form7494 Operation Manual
15
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.
xLightpipe Format. The A/T icon selects the output format for the optical output
connector. Aselects ADAT format; Tselects Toslink. Note that in ADAT
format, the digital stereo output signal is copied to all four sets of ADAT stereo
pairs.