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A PRACTICAL APPROACH
ON DIGILYZER DL1Digilyzer is the latest development in the Minstrument series.
It is a comprehensive and complete digital analyzer that covers most measurements in the digital audio domain. Despite
its amazing power it is battery operated and small enough tofit in the palm of your hand. The DL1 is a highly sophisticatedstand alone digital audio analysis tool.
This guide will give you a closer look at the advantages andfunctions of the DL1. The operation is very straightforward
and intuitive (average familiarization time is less than twominutes). A minimal knowledge of digital audio is all that isrequired to operate the unit.
Try it and see just how easy it is to get all the answers youneed using the power of the Digilyzer DL1.

10 good reasons to use the Digilyzer every day!
1. Listen to the signal - With no signal there is not much toanalyze.
2. Correct wiring - More mistakes are made than you think.
3. The engineers true audio rescue tool.
4. Listen to ADAT signal - No extensive wiring to listen to thetape.
5. Status analysis - a closed book?
6. Panic! Five minutes to air.
7.

Why should I be interested in Bit statistics?

8. Event logging - A measure to rectify all unexpected errors.
9. How loud should broadcast material be? DL1 knows.
10. Why do I need an oscilloscope?

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1. Listen to the signal - with no signal there is not much to analyze.
When it comes to digital audio one major drawback becomes obvious. Humans do not have digital ears and cannot listen to the incoming embedded audio signal. We can help! Simply connect anaudio cable to the DL1 analyzer. Regardless of function selected,
the digital signal is always converted to analog and fed to the internal loudspeaker and the stereo headphone output.

DL1 Screenshot: Fast Access Setup

Hot Key combinations (e.g. ESC + LEFT) allow fast and easy access to the most used settings like volume, audio muting andautomatic gain control setting. No matter which measurement
function is selected the „Fast Access Setup“ screen is displayed.
Forgotten the key combinations? Just press ESC for one second
and the screen, including a help for the shortcuts - is displayed.
The built in automatic gain control (which can easily be enabled/disabled) adjusts the level to suit the speaker or headphone output. Its tremendous dynamic range of 140dB enables to hear eventhe smallest disturbance to the signal and even on silent lines
dithering may be detected. No other tool of this size will detectand tell you the type of dithering within 10 seconds.
If, by accident, an analog signal is connected to the DL1 it obviously will not provide any digital analysis but, and this is unique,it will make the signal audible by enabling an analog path to theinternal speaker. This is a real boon when trying to identify cableconnections.

2. Correct wiring - more mistakes are made than you might think.
Sounds familiar? You are called to a digital set up where you haveno idea who wired what. As usual it is a mix of analog and digitalequipment some of which is pro gear and some domestic. There
are no informations or identifications. How long are the cables?
How is the interface between AES3 and S/PDIF made?

DL1 Screenshot: Level Peak Screen

DL1 is the tool you need. Investigate and localize the problems.
Connect the DL1 to a suspicious output or cable termination andyou can look at the physical properties of the carrier signal. Regardless of what measurement function you have selected you
will find displayed in the top left hand corner of the screen thephysical properties of the carrier signal. Even in an unlocked modethe physical carrier level is measured. The level of the carrier isa good first guide to signal quality. The AES3 standard defines
minimum signal acceptance which with reasonably short cables
should be between 2V - 7Vpp. If there are impedance problems
or longer cable runs the carrier level will drop to below 1V and thereliability is sacrificed.
The DL1 checks the digital signal and the protocol to recognize

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A p p l i c at i o n N ot eerrors. These errors can cause many audible effects and should
ideally never occur. In case such an error occurs it is important to
notice it and, for example, activate the “Event logger“ for further
analysis.

DL1 Screenshot: Carrier Information

An error is indicated by filling the error indicator box black. When
there is no error the filling of the box gets less until its white
again (like a slow decay of a bar graph). In case such errors areindicated it would be necessary to follow the line and locate themismatched format converter or impedance imbalance or indeed
identify the overlong cable. You might be surprised at how oftensuch mistakes occur.

3. The video engineer‘s true audio rescue tool.
Be honest, most video engineers give little consideration to audio
and in the process create format compatibility and synchronization problems. This, despite the fact that most signal degradation
becomes audible before visible effects appear. There is even lessunderstanding of digital audio in the video domain.
That is why the Digilyzer becomes an irreplaceable aid to thevideo engineer. It effortlessly provides all the necessary information to complete the perfect job. The DL1 measures the samplingfrequencies, formats, special status settings, audio content analysis and many more details. All this, in a handy, portable, inexpensive box.
4. Listen to ADAT signals without special wiring.
Try to listen to the individual tracks of an ADAT multi track recorder
or even the new HD24 hard disc recorder without first connecting
all the channels through your mixing console. It just isn‘t possible
as the recorder has no headphones output. The DL1 makes it possible. Simply connect it to the 8 channel optical ADAT output andselect which channel or channel pair is routed to the speaker orheadphone out on your DL1.

DL1 Screenshot: Channel Selection

The Alesis 8 channel light pipe ADAT I + II interface is very widelyused because of its ease of use and small connector size. Thisis especially so in semi pro/domestic applications and computer
based hard disc recorders. The problem is that no measurement ormonitoring equipment can directly handle the ADAT signals. DL1changes that. It can accept and process ADAT signals through its
optical TOS link input. As with any other digital signal DL1 offers
the converted ADAT signal at the speaker or headphone output.
The channel selector allows to quickly toggle through the four
available channel pairs with a single up/down key press.
TASCAM TDIF signals can also be connected to the DL1 using a

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A p p l i c at i o n N ot ecommercially available TDIF/ADAT converter. The monitoring procedures are then identical to those outlined above.
5. Status analysis - a closed book?
Most guides to the interpretation of digital audio channel status
information starts with „...serial data is divided into 192 bit blocks
lined up as bits, groups of bits, nibbles, bytes or words. Refer tothe tables for interpretation.“ Make it easy for yourself. All you
want is to get the essential data of the audio signal out of thebit stream. It is not important what the standard has reserved
for future applications nor to which sub table you should refer tointerpret the flags. The Digilyzer performs all this for you automatically.
DL1 Screenshot: Level PeakDL1 Screenshot: Channel Status

In all measurement functions DL1 will display the essential details of channel status which could affect the signal quality: Theformat, sampling frequency, resolution and the signal purpose. An
consistency check is constantly running as a background task andwill highlight any parameter that shows inconsistency with thephysical parameters e.g. sampling frequency claims to be 44.1
kHz but in reality is 32 kHz.
As soon as the channel status analysis is selected DL1 will interpret the incoming bit sequence in accordance with AES3 and IEC
60958 standards and display the results in blocks and groups. The
display will also keep you informed of the carrier status, giving afeedback on what is connected and any error occurrence.
Professional channel status
Without even needing to understand the interpretation of channel
status you can now, thanks to the DL1, e.g. questions like: Whatformat is being transmitted? answer immediatelly: Professional
without emphasis.

DL1 Screenshot: Professional Format

Channel A and B have their own independent channel status, although in 99% of cases they will be the same. The DL1 Screenshot shows the display for channel A (indicated by “CH A“ onthe top display line) and by quickly flying over the channel status
screen it can be found that there is no difference between channels A and B. Otherwise the small square indicators in front of thechanged label would turn into triangles and constantly toggle.
On the second page, The DL1 Screenshot of the channel status
screen a difference in the channel source and destination data ofthe two channels is indicated.
The DL1 Screenshot also shows that the consistency check,indicates an inconsistency in word length by outlining the label

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Page 4 / 8A p p l i c at i o n N ot e“WLEN 24 BIT“. It reports to have a 24 bit resolution but in reality there are less than 24 bits active. A quick switch over to bits
statistics would indicate the details of the resolution of the operational converter. It is not easy to cheat the DL1‘s eyes!
There is a great deal of channel status information being conveyed
and so the DL1 is programmed to display it within two pages tomake it easier to read and digest.
If you need to see if the channel status is changing in respect tothe current status simply store the current status by accessing“STO“. If any bit in the status is subsequently altered then thesquare flag in front of “RCL“ will turn into a triangle and toggleindicating a discrepancy. Pressing and releasing “RCL“will cause
the screen indicator to toggle between the actual and recalledstatus allowing you to find the difference at a glance. This procedure can be applied to all pages of the status information.
Consumer status
Whenever a consumer status is embedded in the bit stream DL1
automatically switches to transparent consumer format, again
giving you all interpretation without the need for any tables.
DL1 Screenshot: Consumer Format page 1

DL1 Screenshot: Consumer Format page 2

Any difference between channel A and channel B will be indicatedby the square bullet signs turning to triangles and toggling. Aswell any deviation to the stored status will be shown in the bullet
sign in front of “RCL“.
The Digilyzer also interprets the fairly complex nested category
tables providing simple device category statements such as “LASER OPTICAL PRODUCT“, “MINI DISC SYSTEM“, etc.. So theDL1 will even indicate whether the material is original or once
only copied material.

6. Panic! Five minutes to air.
We have all been there! Five minutes to air and the main guest
arrives with his small mini disc system and the request to record
the interview. Given time there would be no problem but with
only five minutes to go?
The problem is that in the available digital environment is no analog output. You need to wire the minidisk into the digital bus output. No problem with DL1. Connect it into the digital output andthen connect mini disc player to the DL1‘s headphone output.
The Digilyzer is a full 24 bit 96 kHz D/A converter that meets thehighest requirements of broadcast and live environments. A little
word of warning: do not forget to disable the automatic gain control and activate a stereo function like vu ppm.
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A p p l i c at i o n N ot eIt‘s best to prepare one of following cables:• 3.5mm stereo jack to 3.5mm stereo jack cable• 3.5mm stereo jack to 2x RCA• 3.5mm stereo jack to 2x XLR
7. Why should I be interested in Bit Statistics?
Because it saves time and money!
Bit statistics provide a quick, easy to read, but detailed overview
of the activity in the fairly complex serial bit stream of the twochannels plus some important ancilliary information.

DL1 Screenshot: Bit Statistics

Any bit remaining at 0 or 1 in each sample is represented on thescreen accordingly. However if it is active and therefore changing it will be displayed on screen with an up/down arrow sign.
The example screen shown on the left displays the expressions
AUX and AUDIO DATA (to clarify the bit weighting the LSB andMSB position of the AUDIO DATA is marked). The two lines below
these signs represent the 32 bit audio word for both channels.
Since the MSB is on the right side the right bits always have tobe active. After the active bits the remaining (inactive) bits haveto be zero. We can easily count the arrows from right to left tofind the actual word width or binary resolution. The DL1 will countthese constantly for you and displays the measured resolution in
the top left corner of the screen, e.g. 20 bit in our example DL1
Screenshot.
On the bottom line you will see displayed the ‚claimed‘ resolution.
Other digital tools only provide the status information and not themeasured resolution. The DL1 measures both so you can ensurethat a device claiming to be 22 bit and priced accordingly actually
delivers on its promises.
Should you ever find steady 0 or 1 bits within the row of active bits
you can assume that the transmitting audio codec is defective. In
most cases hanging bits sound terrible but may, if they are close
to the LSB, have only subtle audible effects. Investigations withthe distortion function may enable rectification of the problems.
The Digilyzer DL1 is the only palm top unit that performs thesedetailed measurements!

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8. Event logging - A measure to rectify all unexpected errors.
Intermittency is probably the most annoying thing we ever encounter. Things happen just when you don‘t need them but refuse to happen when you try and investigate the cause. Suchproblems are fairly prominent in broadcast where video and audio
data streams are mixed together, hopefully synchronized. How
can you measure the quality of this synchronization? Activate theevent logger at the DL1 and sit back.
DL1 Screenshot: Event Logger

As soon as the event logger is active it records any irregularity ofthe digital signal such as:• Unlock/lock carrier signal (e.g. physical disconnection)• Receiver confidence errors (e.g. poor carrier signal quality, eyepattern out of specs)• Parity errors (e.g. indicating a transmission error of at least onebit)• Change in the status information (e.g. change of source)• Invalid samples (e.g. conversion error of CD player)
The DL1 event logger records many different events (not only thecommon ones like lock/unlock, parity error, ...). Things like changesof sample frequency, changes of carrier level, consistency check
results, audio signal clipping and many more are required.
To make navigation through such an enormous information flow
simply to mechanism are included in DL1:
• Events are „bundled“ in time clusters (intervals). These timeintervals can be zoomed: zoom in to get more details, zoom
out to get a better overview or to read out the events which
occurred during the whole recording period. Using this facility
you can use DL1 to listen to any CD or master and it will show
you the number of errors of the CD. This is probably the best
and most inexpensive way of ensuring that only top quality
mastering or broadcast material is supplied.
• If e.g. a parity error fills up your screen you simply can„mask“ this error from displaying. This mask is only active
when you analyse the logged data - all events are recorded so
you never miss one.
Identifying even those slips in synchronizers which seldomly occur becomes an easy task to perform reliably.

DL1 Screenshot: Logger Mask Screen

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The DL1 provides sufficient log capacity to last for days or evenweeks.

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9. How loud should broadcast material be? DL1 knows.
Broadcast levels are limited to maximum output levels to ensurethat transmission lines are not overloaded. The standard defines amaximum RMS level. This is no longer relevant in the digital age.
What is now important is the maximum peak level which mustnever be exceeded to avoid audible distortion.

DL1 Screenshot: vu + PPM display

Even though the maximum peak level is observed it is very noticeable when tuning through the radio stations that some channels
appear louder than others. This is a result of compression of thesignal, a trick, which is often used extensive to increase station
identity awareness. The use of compression and other dynamic
signal processing gives an apparent increase in loudness without
exceeding the maximum peak level.
DL1 features both a peak level meter (ppm) and a volume unit
meter (vu) in parallel. The ppm will indicate the peak levels whilst
the vu-meter will give a first approximation of the perceived loudness of the signal and as such reflects the grade of compression
being used.
Simply feed the broadcast signal into the DL1 and it will display,for both channels, the peak levels and also, as thickened bars, thevu levels. Max hold as well as the total max level are displayed inparallel. The closer the vu bar comes to the ppm level (centre bar)
the higher the compression of the audio material.

10. Why do I need an oscilloscope?
Have you ever been able to look at dither and listen to it at thesame time? DL1 makes it reality.
The DL1 scope is an ideal tool for educational purposes, helping
to understand digital measurements and interpreting the results.

DL1 Screenshot: Oscilloscope screen

The oscilloscope function can be used with any digital audio material. It will display the waveform of the signal in the automatic
scaling display. The amazing dynamic range of the Y-scale gives
results from 25% of the signal per division right down to 0.1ppm
per division. This allows to even see the LSB of 24 bit audio material and look at the dithering.
Check it out.

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