Whirlwind AESDA User's Manual
Contents
1. of power at a Voltage range from 3 5VDC to 15VDC This allows the AESDA to operate ona wide variety of power sources including car batteries portable camera batteries or a wall wart type of power supply Digital Monitor LED Function Details Digital Info Indicators Sample Rate 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 LED should be illuminated at one time in normal operation With no input signal the Fault LED and the No Lock LED in Fault Type mode will be illuminated instead 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 digital audio stream s Status bit indicates Consumer mode and is off in Professional mode Note that this indicator only presents validly when the AESDA is locked to a valid PCM audio data stream 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 prese2. AESDA PORTABLE AES TO ANALOG CONVERTER The Whirlwind AESDA is a portable device for converting AES 3 and S PDIF digital audio signals into analog audio signals Digital input to the AESDA is through the female XLR or BNC 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 decoded analog audio 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 versions of AES 3 can be decoded by the AESDA Additionally the AESDA 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 99 Ling Road Rochester NY 14612 Phone 585 663 8820 Fax 585 865 8930 Email sales whirlwindusa com http www whirlwindusa com Theory of Operation The AESDA was designed to provide a portable means of converting an AES 3 or S PDIF digital audio stream into a professional high quality two channel analog audio output The digital in
3. METERS AES EBU INPUT 45 33 27 21 18 15 12 B 3 6 9 12 15 CLIP dB NO ERROR B OVER TEMP CHANNEL A OUTPUT LEVEL METERS OOO A OUTPUT BAR ANALOG OUTPUTS CHANNEL A CHANNEL B CE miinaa Controls and Functions 1 AES EBU Input Connectors are provided for Digital Audio input 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 accept AES EBU and S PDIF signal levels ranging between 5V p p and 250mV p 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 the eleventh is red Two measurement scales are provided 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 OdBV with the red LEDs illuminating for an output level of 1 8dBV 99 Ling Road Rochester NY 14612 Phone 585 663 8820 Fax 585 865 8930 Email sales whirlwindusa com http www whirlwindusa com CHANNEL B RoHS MADE IN USA 4 3 Analog Output Jacks are balanced male XLR connectors capable of driving loads from 600 Ohms to near infin
4. annunciated are Hardware internal diagnostics No Lock or no signal present Parity or Bit Length error CRC error if the audio data present is in Professional mode Signal Confidence wave shape level or symmetry is borderline or out of tolerance Validity Bit not present Over Temperature and No Fault Detected
5. ates 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 end of each frame The digital receiver in the AESDA recalculates this CRC 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 Mode AES 3 and S PDIF do not use CRC checking so this LED will be off when receiving audio data of this type Confidence Flag 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 incorrect cable impedance or asymmetry in the signal the 1 part and the O part of 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 and probably not reliable in the long run When other signal type errors are present this is indicative of a bad cable too long of a cable run a bad transmitter or an excessively noisy environment Validity Bit The Validity Bit LED Indicator illuminates when the Left or Right or both of the Validity Bits indicate invalid data These bits are embedded in the audio
6. data and there is one validity bit in each subframe When one channel is invalid the Validity Bit LED will flicker if both channels indicate invalid the LED will be steadily on No Error The No Error LED Indicator is illuminated when no detected error is present This provision allows at least one LED to be illuminated when Fault Type mode is entered and there are no faults Over Temp The Over Temp LED Indicator illuminates if the detected temperature inside the 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 permanent damage to the AESDA No shutdown action is instigated by the AESDA itjust serves as a warning to the user Warran This products 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 replace the unit at our option and pay the return postage 13 N DIGITAS MONITOR 44 1 kHz j HARDWARE FAULT 48 kHz 88 2 kHz PARITY ERROR m 96 kHz CRC ERROR 1 176 4 kHz CONFIDENCE FLAG ONS 192 kHz VALIDITY BIT e AUDIO CONSUMER PRE EMPH r 0 ai FAULT raut souRCE MODE a T TYPE POWER D INPUT DOT AESDA NO LOCK PORTABLE AES TO ANALOG CONVERTER LEVEL
7. is displayed 7 The Power LED is illuminated when the Power switch is ON It will dim as the batteries lose power thus giving an indication of remaining battery life 8 The Power Switch applies power from the external supply or the batteries When power is applied the AESDA runs internal diagnostics culminating in 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 normal operating mode 9 The Digital Monitor Select switch selects whether Digital Info digital signal parameters or Fault Type information is displayed on the vertical ten segment Digital Monitor LED array 10 Phones Out Jack provides a high quality analog version of any digital audio source received by the AESDA Peak output level is 4dB and the output is capable of driving headphones from 16 to 100 Ohms impedance It can also be 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 5mm TRS jack 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 the Analog Outputs or the meters 12 The Battery Compartment is a slide out drawer that accepts four AA size cells Either alkaline cells or externally rechargeable Nickel Metal Hydride NiMH or Lithium lo
8. ity at output levels of up to 27dBV although the outputs are metered only to 18dBV Output noise is less than 95aB Total harmonic distortion is less than 0 004 at OdBV of output and less than 0 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 signal ground pin 2 is positive pin 3 is negative and the shell is case ground 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 by selecting Analog Output with the Meter Source Select switch 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 power allowing longer operation under battery power 6 The VU Meter Source Select switch controls whether the level of the Digital Input or the Analog 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 Outputs XLR Connectors after the Output Level controls
9. n 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 AESDA does not have internal battery recharge capability 13 The 6VDC external power jack is a 5 5mm x 2 1mm size with the center contact wired positive and the barrel contact negative When a plug is inserted into this connector the internal batteries are disconnected A6VDC 2 5A plug 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 familiar AC wall wart plug in power supplies 14 The Digital Monitor ten segment LED array displays operational status and fault diagnostics The type of information shown on this display is controlled by the Digital Monitor Select switch In the Digital Info 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 emphasis is enabled and if a fault is present In the Fault Type position it will indicate the type of fault s present if any and also if no fault is detected The types of faults
10. nt 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 the digital input signal has been detected The user then can switch the unit over to the Fault Type display to further identify the fault Fault Type indicators Hardware Fault 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 No Lock 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 digital audio stream to either digital input will cause this indicator to extinguish Parity Error The Parity Error LED Indicator illuminates when the incoming data did not have an even number of ones and zeros or if the number of bits was not 32 Typically parity and bit length errors are indicative of weak or noisy signals Parity and bit errors are also typically not consistent between fields of data so flickering of this LED is not uncommon in the presence of these types of errors CRC Error The CRC Error LED Indicator illumin
11. put is extensively screened at receiving with faults in the data or transport annunciated by type Adual 11 segment VU meter monitors the audio level from the 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 Aten segment red LED bar serves to indicate the various operating modes and detected faults if any Aswitch 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 controls to the desired value Aheadphone monitor jack with separate level control is also provided for checking the analog audio signal Recommended headphone impedance is between 16 and 100 Ohms This jack can also be used as an unbalanced line level output Primary power for the unit can be sourced from four AA cells Alkaline Lithium lon 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
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