ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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DXA
SERIES
AES/EBU DIGITAL AUDIO
DISTRIBUTION AMPLIFIERS
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OPERATING AND MAINTENANCE MANUAL
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© Copyright 2011, ATI Audio Inc.
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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PURPOSE
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The DXA Series of Digital Audio Distribution Amplifiers is designed to regenerate,
isolate and distribute digital audio data formatted in accordance with
specifications AES3-1992 and IEC 958. This is commonly called AES/EBU
formatting.
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DXAxxx-XLR models use XLR connectors and operate from and drive a 110-ohm
balanced shielded twisted pair distribution system per AES3-1992.
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DXAxxx-BNC models use BNC connectors and operate from and drive singleended 75-ohm coaxial cable per AES-3id-1995 and are designed to integrate
easily into video facilities.
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SP/DIF (consumer) formatted digital audio data differs primarily in the use of
consumer type "RCA" audio connectors in an unbalanced 75 ohm system and
can be handled by a DXAxxx-BNC with use of an RCA to BNC input cable.
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FEATURES
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• Accepts sample rates from 27 to 96kHz
• Loop-thru transformer balanced and isolated inputs
• Switchable input termination resistors
• Individual, transformer balanced and isolated 110 ohm XLR outputs
• Individual isolated 75-ohm BNC outputs
• Single or dual inputs
• Up to 12 XLR or 24 BNC outputs
• Quiet, internal linear power supplies
• Attractive, one rack unit package
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DESCRIPTION
INPUTS
Incoming AES/EBU formatted digital audio data is applied to input transformer T8
(and T9 for second input channel of dual unit). Both XLR and BNC inputs are
balanced and DC isolated from ground. Input blocking capacitors C22 (C24)
prevent accidental DC inputs from saturating (and perhaps damaging) the input
transformers. Input termination resistors R25 (R26) at 75 ohms for BNC (and
SP/DIF) inputs or 110 ohms for XLR inputs can be switched in or out of the circuit
with rear panel DIP switches S1a (S1b). Inputs should always be terminated
unless they are looped-thru to another device or DXA input. The last device or
input should always terminate the line.
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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RECEIVERS
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The equalized AES/EBU data stream is applied to the receiver circuit U8 (U17), a
Crystal Semiconductor CS8414 96kHz Digital Audio Receiver IC. The CS8414
receives the data, recovers the clock and synchronization signals and separates
the audio and digital data. The audio data may be 16 to 24 bits at sample rates
from 27 to 96 kHz.
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OUTPUT DRIVERS
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DXAxxx-XLR use balanced, 110-ohm, transformer-coupled outputs and XLR type
connectors. DXAxxx-BNC units use the alternative 75-ohm unbalanced outputs
to BNC coax connectors. The XLR outputs are in full compliance with
specification AES3-1992 and the BNC outputs are in accordance with the
recommendations of AES-3id-1995. RS-422 differential line drivers U1 and U2
(U5 and U6) provide a balanced drive for XLR outputs of 8Vp-p, open circuit
through 110-ohm source resistance to yield 4Vp-p when loaded by a 110-ohm
load. XLR outputs are transformer-coupled for ground isolation. Each side of the
differential line driver output is used to separately drive a 75-ohm capacitorcoupled BNC output. Each BNC output provides 4Vp-p open circuit thru 75 ohms
for a loaded output of 2Vp-p. Although the two sides of a differential line driver
are out of phase with each other there is no phase difference in the recovered
audio since the AES/EBU digital data is defined only by the presence or absence
of transitions. It makes no difference whether those transitions are hi-to-low or
low-to-hi.
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REFERENCE OSCILLATORS AND POWER SUPPLIES
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U7 and U13 provide regulated and quiet +/-5VDC for all circuits. Power
transformer primary windings are paralleled for 115VAC or wired in series for
230VAC. Jumper group E1 allows field modification if necessary.
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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INSTALLATION:
LOCATION
To avoid addition of jitter (timing variations) to the digital bitstream, which could
cause noise and distortion in the recovered audio, avoid locating the DXA in
close proximity to a high energy, high frequency switching type power supply or a
power amplifier that utilizes a switching supply. If possible, do not power both
devices from the same AC power line.
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Expensive components start to die at internal temperatures above 70°C (158°F).
We recommend that you maintain rack temperatures below 50°C (122°F) to
prevent excessive internal temperature buildup. This is another good reason not
to mount the DXA directly above that 500W power amplifier. Don’t force the DXA
to support the weight of 28 coax or 16 XLR cables (especially when you drop that
500W power amplifier on the cable bundle); support the cables.
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POWER
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If it is necessary to convert a unit wired for 115VAC to 230VAC operation, unplug
the unit from the power source, remove the four cover mounting screws and
locate the E1 jumpers next to the power transformer. Clip the jumpers 1-2 and 34 (don’t unsolder), jumper from 2-3 carefully soldering together the free ends of
2-3 previously clipped. This procedure is recommended to avoid soldering
damage to the multi-layer PC board.
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WIRING
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XLR-equipped units require special controlled impedance, 110 ohm, low loss, foil
shielded, twisted pair cables. Standard audio cable is not recommended except
for runs of only a few feet. Belden and most other cable manufacturers offer
special digital audio cabling for this application. BNC types use 75-ohm coax
(RG59). Select a cable with losses less than 20dB at 12MHz (for data rates up to
96kHz) at the maximum distance you require.
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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SPECIFICATIONS:
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INPUTS
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Connectors: XLR female or BNC, DC isolated from chassis
Input connector pairs paralleled for loop-thru
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Level: 200mVp-p minimum
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Impedance: Transformer isolated, capacitor coupled, balanced and
floating, XLR inputs 110 ohms; BNC inputs 75 ohms
Terminating resistors may be switched in or out on rear
panel
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Sample Rates: Accepts 27kHz to >100kHz
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OUTPUTS
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Connectors: XLR male, 6 or 12; BNC chassis mount, 12 or 24
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Levels: XLR, 4Vp-p loaded at 110 ohms; BNC, 2Vp-p loaded at 75
ohms
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Impedances: XLR, 110 ohms, balanced, transformer isolated and
capacitor coupled; BNC, 75 ohms, unbalanced, capacitor
coupled
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Output Jitter: <3 nanoseconds peak-to-peak at 96kHz sample rate
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Output Delay: Three frames (sample intervals) at the sample rate
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INDICATORS
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Power: Lit RED for ON
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POWER Internal supply, 115/230VAC (selectable via internal wiring
change) ±10%, 50/60Hz, 10VA, IEC320 3 pin connector
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SIZE 1 RU, 19” (48.3cm) W X 1-¾” (4.5cm) H X 7” (18cm) D
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WEIGHT 5lbs (2.3kg) Shipping Weight
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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MODELS AVAILABLE
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DXA112-BNC 1 input to 12 outputs, BNC connectors
DXA112-XLR 1 input to 12 outputs, XLR connectors
DXA124-BNC 1 input to 24 outputs, BNC connectors
DXA212-XLR Dual 1 input to 6 outputs, XLR connectors
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DXA224-BNC Dual 1 input to 12 outputs, BNC connectors
ATI Audio Inc.
Tel: 856-719-9900
sales@atiaudio.com
www.
audio.com
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One Year Limited Warranty
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ATI warrants this product to be free from defects in materials and workmanship to its original
owner for a period of one year from date of purchase. ATI will repair or replace such product or
part thereof, which upon inspection by ATI, is found to be defective in materials or workmanship.
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The Proper Return Authorization Number must be obtained from ATI in advance of return.
Contact ATI at 856-626-3480 or email sales@atiaudio.com to receive the number and
instructions for return of your unit.
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A written statement providing the name, address, daytime telephone number and email address
of the original owner, together with receipt from the original purchase, and a brief description of
any claimed defects, must accompany all returns. Parts or product for which replacement is made
shall become the property of ATI.
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The customer shall be responsible for costs of transportation and insurance to the factory of ATI,
and shall be required to prepay such costs.
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ATI shall use reasonable efforts to repair or replace any product covered by this limited warranty
within thirty days of receipt. In the event repair or replacement shall require more than thirty days,
ATI shall notify the customer accordingly. ATI reserves the right to replace any product that has
been discontinued from its product line with a new product of comparable value and function.
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This warranty shall be void in the event a covered product has been damaged, or failure is
caused by or attributable to acts of God, abuse, accident, misuse, improper or abnormal usage,
failure to follow instructions, improper installation or maintenance, alteration, or lightning, power
fluctuations and other incidental or environmental conditions. Further, product malfunction or
deterioration due to normal wear is not covered by this warranty.
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ATI DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WHETHER OF
MERCHANTABILITY OF FITNESS FOR A PARTICULAR USE, EXCEPT AS EXPRESSLY SET
FORTH HEREIN. THE SOLE OBLIGATION OF ATI UNDER THIS LIMITED WARRANTY SHALL
BE TO REPAIR OR REPLACE THE COVERED PRODUCT, IN ACCORDANCE WITH THE
TERMS SET FORTH HEREIN. ATI EXPRESSLY DISCLAIMS ANY LOST PROFITS, GENERAL,
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES WHICH MAY RESULT FROM
BREACH OF ANY WARRANTY, OR ARISING OUT OF THE USE OR INABILITY TO USE ANY
ATI PRODUCT.
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Some states do not allow the exclusion or limitation of incidental or consequential damages or
limitation on how long an implied warranty lasts, so the above limitations and exclusions may not
apply to you.
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This warranty gives you specific legal rights, and you may also have other rights that vary from
state to state.
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ATI reserves the right to modify or discontinue, without prior notice to you, any model or style
product.
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If warranty problems arise, or if you need assistance in using your product contact us.
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