Whirlwind Portable AES to Analog Converter AESDA User manual

The WhirlwindAESDAis a portable device for convertingAES-3 and
S/PDIF digital audio signals into analog audio signals. Digital input to
theAESDAisthroughthefemaleXLRorBNC.There are level meters
that display the level of the incoming digital signal or they can be
switched to display the analog output signal level. Each of the two
decodedanalogaudio outputs has an independent level control, from
which the signal is sent to the analog metering circuits and male XLR
outputs. Another unbalanced analog output is provided on a 3.5 mm
TRS jack, with its own level control, for use with headphones or as an
unbalanced line level driver. Both professional and consumer
versionsofAES-3canbedecodedbytheAESDA.
Additionally, theAESDA provides diagnostic analysis of the incoming
AES-3 and S/PDIF digital signals for help in troubleshooting signal
faults. The digital monitor section identifies the sample rate and
characteristics of the incoming digital signal, and if there is a problem
in the digital audio stream several different fault types can be
identified.
Theory of Operation
TheAESDAwasdesigned to provideaportablemeans of convertinganAES-3 or S/PDIF
digitalaudiostreamintoaprofessional high-qualitytwo-channelanalogaudiooutput. The
digital input is extensively screened at receiving, with faults in the data or transport
annunciatedbytype. Adual 11-segmentVU metermonitors theaudio level fromthe DAC
or the level at the output. In the interest of conserving battery power, two display modes
are available on the VU meter. One is a bar graph of the signal level, the other is a single
LED which indicates the peak instantaneous signal level, with the single LED consuming
less power than the bar graph. A ten-segment red LED bar serves to indicate the various
operating modes and detected faults, if any. A switch selects the function of this LED bar,
either to indicate operating mode, detected sample rate, etc., or to display any detected
fault. The analog output has separate level controls for the left (A) and right (B) side.
Output level may be set by selecting the analog output on the VU meters, and setting the
controlstothedesiredvalue. Aheadphonemonitorjack withseparate levelcontrolisalso
provided for checking the analog audio signal. Recommended headphone impedance is
between16and100Ohms. Thisjackcanalsobe usedasanunbalancedlineleveloutput.
Primary power for the unit can be sourced from four “AA” cells (Alkaline, Lithium-Ion or
Nickel-Metal-Hydride cells are recommended). An external coaxial power jack (5.5mm x
2.1mm) is provided for situations where battery power may not provide an adequate
length of operation. The external power source should be able to provide 12 Watts of
powerataVoltagerange from3.5VDCto15VDC. This allows theAESDAtooperate on a
widevarietyofpowersourcesincludingcarbatteries,portablecamerabatteries,or a“wall
wart”typeofpowersupply.
Digital Monitor LED Function Details
Digital Info Indicators
SampleRate
There are six sample rate indicators that show the closest standard sample rate to
the signal as received: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, and 192kHz.
Signals that have sample rates lower than 44.1kHz may be locked to and decoded
by the AESDA, but their sample rate will not be displayed. Only one sample rate
LEDshouldbeilluminated at onetime in normaloperation. Withnoinputsignal, the
FaultLEDandtheNoLockLED(inFaultTypemode)willbeilluminatedinstead.
Audio
The Audio LED indicator illuminates when the input digital data stream has been
determined to be Pulse-Code Modulated (or PCM) digital audio. For other digital
inputs that are not PCM audio, such as TDM data to DTS-CD, this indicator will be
off.
Consumer
The Consumer LED indicator illuminates when the Pro/Consumer mode bit in the
digitalaudiostream'sStatusbitindicatesConsumermode,andisoffinProfessional
mode. Note that this indicator only presents validly when the AESDAis locked to a
validPCMaudiodatastream.
Pre-Emph(asis)
The Pre-Emph(asis) LED Indicator illuminates when the digital audio stream's
Status bit field for this condition indicates that it is present. Typically, pre-emphasis
is only used for sample rates of 32kHz, 44.1kHz, and 48kHz. When the indicator is
off, it indicates that the audio signal embedded in the digital stream has not been
pre-emphasized.
Fault
The Fault LED indicator illuminates when a detected fault, either in the hardware or
thedigital inputsignalhas beendetected. Theuserthen canswitchthe unit overto
theFaultTypedisplaytofurtheridentifythefault.
Fault Type indicators
HardwareFault
The Hardware Fault LED Indicator is illuminated if anything in the power-on
diagnostic tests did not pass, or if the information presented by the control switches
is invalid or cannot be interpreted. The unit may not operate properly with this LED
illuminated.
NoLock
The No Lock LED Indicator illuminates if no signal is present on either of the two
digital input connectors, or if the signal cannot be interpreted. Application of a valid
digitalaudiostreamtoeitherdigitalinputwillcausethisindicatortoextinguish.
ParityError
The Parity Error LED Indicator illuminates when the incoming data did not have an
evennumber of onesand zeros,orifthe number ofbitswasnot 32. Typically,parity
andbit-lengtherrorsareindicativeof weak or noisy signals. Parityandbiterrorsare
also typically not consistent between fields of data, so flickering of this LED is not
uncommoninthepresenceofthesetypesoferrors.
CRCError
The CRC Error LED Indicator illuminates when an AES Professional Data Block
Cyclical Redundancy Check did not pass. When generated, the data is passed
through a CRC generator, which calculates and embeds an 8-bit check word at the
endofeachframe. Thedigital receiver intheAESDArecalculatesthisCRC number
from the received data and compares its result to the CRC number received. If the
two do not match, then the data was not received the same way that it was
transmitted, i.e., there may be one or more data bits that are in error. Note that
Consumer ModeAES-3 and S/PDIF do not use CRC checking, so this LED will be
offwhen receivingaudiodataofthistype.
ConfidenceFlag
The Confidence Flag LED Indicator illuminates if excessive distortion is detected in
the digital signal received. The distortion may be from low signal level, excess or
incorrectcableimpedance,or asymmetryinthesignal(the“1”partand the“0”partof
the signal not of equal length within a specific percentage). If only this error exists,
without Parity, CRC, or No Lock errors, it is indicative of a signal that is marginally
useable,andprobablynotreliablein the longrun. Whenothersignal-typeerrorsare
present,this is indicativeofabad cable, toolongofa cable run,a badtransmitter,or
anexcessivelynoisyenvironment.
ValidityBit
TheValidityBitLED IndicatorilluminateswhentheLeftorRightorbothofthe Validity
Bits indicate invalid data. These bits are embedded in the audio data, and there is
one validity bit in each subframe. When one channel is invalid, the Validity Bit LED
willflicker;ifbothchannelsindicateinvalid,theLEDwill besteadilyon.
NoError
The No Error LED Indicator is illuminated when no detected error is present. This
provisionallowsatleastoneLEDtobeilluminated when FaultTypemode isentered
andtherearenofaults.
OverTemp
TheOverTempLED Indicator illuminatesifthe detected temperatureinsidethe unit
exceeds 85°C. This temperature is the upper limit for reliable operation of the
various internal components, and if exceeded for a long period of time, could cause
permanentdamagetotheAESDA. NoshutdownactionisinstigatedbytheAESDA,
itjustservesasawarningtotheuser.
AESDA
PORTABLE AES TO ANALOG CONVERTER
Warranty
This product is guaranteed for one year from the date of purchase against manufacturing defects. For warranty service, return the
unit, along with the original sales receipt, to: whirlwind, 99 Ling Road, Rochester, NY 14612, postage prepaid. We will repair or
replacetheunitatouroptionandpaythereturnpostage.
99 Ling Road . Rochester, NY 14612
Phone [phone] . Fax [phone]
Email: [email protected]
http://www.whirlwindusa.com

7.ThePowerLEDisilluminatedwhenthePowerswitchisON. Itwilldimasthe
batterieslosepower,thusgivinganindicationofremainingbatterylife.
8. The Power Switch applies power from the external supply or the batteries.
Whenpoweris applied,theAESDArunsinternal diagnostics,culminatingin an
LED display test where the 32 LEDs in the three displays are illuminated in
sequence, then extinguished in the same manner. The unit then goes into its
normaloperatingmode.
9. The Digital MonitorSelectswitchselectswhether“DigitalInfo”(digitalsignal
parameters) or “Fault Type” information is displayed on the vertical ten-
segmentDigitalMonitorLEDarray.
10.PhonesOutJackprovidesa high-qualityanalogversionofanydigital audio
source received by theAESDA. Peak output level is +4dB, and the output is
capableofdriving headphonesfrom16to 100Ohmsimpedance.It canalsobe
used to feed an unbalanced line input. The left channel (A) is connected to the
tip, the right (B) to the ring, and the sleeve to common of the unbalanced
3.5mmTRSjack.
11. Phones Vol(ume) Control adjusts the analog audio level present on the
Phones output (3.5mm) TRS jack. The setting of this control has no effect on
theAnalogOutputsorthemeters.
12. The BatteryCompartment isaslide outdrawer thataccepts four“AA”size
cells. Either alkaline cells or externally-rechargeable Nickel-Metal-Hydride
(NiMH) or Lithium-Ion cells may also be used. Battery life is highly dependent
upon several factors, including load impedance, output level, the use of
headphones, and the mode of the level meters. Typical loading will provide
about four hours of operation with fresh batteries. The AESDAdoes not have
internalbatteryrechargecapability.
13. The 6VDC external power jack is a 5.5mm x 2.1mm size with the center
contactwiredpositive andthebarrelcontact negative. Whenaplugisinserted
intothis connector,theinternal batteriesaredisconnected. A6VDC2.5Aplug-
in power supply is supplied with the unit. Input voltage can be anywhere from
4.8VDC to 15VDC, provided the power source can deliver at least 12 Watts
peak. This wide input range allows the AESDA to be powered from lantern
batteries, auto batteries, and camera batteries, as well as the familiarAC “wall
wart”plug-inpowersupplies
14. The Digital Monitor ten-segment LED array displays operational status
and fault diagnostics. The type of information shown on this display is
controlledbythe DigitalMonitor Selectswitch. Inthe“DigitalInfo” position,the
display shows the detected sample rate, the type of data present, if the data is
consumer or professional mode audio (if an audio stream is detected), if pre-
emphasisisenabled, andifa faultispresent. Inthe“FaultType”position,itwill
indicate the type of fault(s) present, if any, and also if no fault is detected. The
typesoffaultsannunciatedare Hardware(internaldiagnostics),NoLock(or no
signal present), Parity or Bit Length error, CRC error (if the audio data present
isin Professionalmode),Signal Confidence(waveshape,level orsymmetryis
borderlineor out-of-tolerance),ValidityBit notpresent,OverTemperature,and
NoFaultDetected.
Controls and Functions
1. AES/EBUInput Connectorsareprovidedfor DigitalAudioinput. The
BNC connector provides an input for 75 Ohm unbalanced S/PDIF
audio, and the female XLR provides an input for 110 Ohm balanced
AES/EBU audio. Both inputs are transformer and DC isolated (up to
50V), and acceptAES/EBU and S/PDIF signal levels ranging between
5Vp-pand250mVp-p.
2. VU Meters, two eleven segment LED arrays, can display either the
digital input level or the analog output level. The first ten LEDs are
green;theeleventhisred. Twomeasurementscalesareprovided,one
for the digital input, which is in dB Full-Scale, or dBfs units, with the red
LEDs illuminating at a point about 1 to 2dB less than the maximum
output of the Digital-to-Analog converter, and one for the analog
outputs. This is measured in dBV, where 1V RMS of output equals
0dBV,withtheredLEDsilluminatingforanoutputlevelof+18dBV.
3.Analog OutputJacksare balancedmale XLRconnectors, capableof driving
loadsfrom 600Ohms tonear infinityatoutput levelsofup to+27dBV,although
theoutputs aremeteredonly to+18dBV.Output noiseis lessthan -95dB.Total
harmonicdistortionislessthan 0.004%at0dBVofoutput,andless than0.01%
at +18dBV of output. Frequency response is flat to within 0.2dB from 22Hz to
20kHz. Each output has its own independent level control, which, along with
the VU meters, allows precise setting of signal level for each channel. Pin 1 is
signalground,pin2ispositive,pin3isnegative,andtheshelliscaseground.
4. Output Level Controls independently control the level presented at the
analog outputs. The level of each output may be monitored on the VU meters
byselectingAnalogOutputwiththeMeterSourceSelectswitch.
5. The Meter Mode Select switch controls how the VU Meter information is
displayed. In “DOT” mode the VU display will illuminate the LED that most
corresponds to the output level at that instant. In “BAR” mode, the VU display
operates as a conventional bar-graph LED display. The dot mode conserves
powerallowinglongeroperationunderbatterypower.
6.The(VU)MeterSourceSelect switchcontrolswhetherthelevelof theDigital
Input or theAnalog Outputs are selected for monitoring on the VU Meters. In
the “D(igital) Input” position, the Analog level of the decoded Digital Input is
displayed. In the “A(nalog) Output” position, the level present at the Analog
OutputsXLRConnectorsaftertheOutputLevelcontrolsisdisplayed.
99 Ling Road . Rochester, NY 14612
Phone [phone] . Fax [phone]
Email: [email protected]
http://www.whirlwindusa.com
INPUTS
PHONES
CHANNEL B
INFO
AESDA
LEVEL METERS
PORTABLE AES TOANALOG CONVERTER
NO LOCK
PHONES VOL
FAULT
TYPE
DIGITAL
FAULT
PRE-EMPH
CONSUMER
METERS
A. OUTPUT
D. INPUT
SOURCE
POWER
BAR
DOT
MODE
CRC ERROR
PARITY ERROR
NO ERROR
VALIDITY BIT
192 kHz
AUDIO
176.4 kHz
88.2 kHz
96 kHz
48 kHz
HARDWARE FAULT
DIGITAL MONITOR
44.1 kHz
AES/EBU
CHANNEL
CHANNEL B
OUTPUT LEVEL
-33-45 -18 -15
-27 -21 -3-9 -6 -12 0
-15
-27 0 +3-9 -3 +15+9 +12
+6 CLIP
OVER TEMP
CHANNELA
A
ANALOG OUTPUTS
6VDC 1
23
4
56
8
7
9
10
11
12
18
13 14
B
A
dBfs
dBV
MADE IN USA