ATI Technologies BU400 Operating instructions

BU400,BU400B,UB400B,
UB400B, & BI400
IHF-PRO INTERFACE AMPLIFIER
OPERATING AND MAINTENANCE MANUAL
CD Copyright 1997-2007, Audio Technologies Incorporated - Printed in LISA
Audio Technologies Inc. I 154 Cooper Road #9021 West Berlin, NJ 080911 Voice 856-719-99001 Fax [phone] www.rzlI]audio.com

GENERAL
Consumer audio equipment can offer unique features, good performance and
attractive pricing making it very desirable for professional use. Unfortunately, RF
pickup, ground coupled cross talk, high frequency roll off, hum loops and distortion
are often the results ofthe direct connection of low level unbalanced
IHF outputs into
the
600 ohm balanced systems used in studio or broadcast environments. Consumer
and semi-professional equipment can be identified by their use of RCA type
connectors, typical of home hi-fi equipment, for their
IHF inputs and outputs.
Professional systems typically use
XLR type connectors or hard-wired connections.
The BI100, BU400 and UB400 are interface amplifiers designed to interconnect
consumer grade
and semi-professional equipment into professional, balanced, low
impedance audio systems.
The BI100 is a bi -directional stereo interface, which bridges a stereo pair of
professional 600 ohm balanced
or unbalanced +4dBm lines and. converts those
signals to a nominal .25volt
IHF level (-10dBu). The IHF output can feed, for example,
the record inputs of a consumer grade cassette or
DAT recorder. Simultaneously the
BI100 also converts the unbalanced, high impedance, stereo, .25-volt IHF playback
outputs from the tape deck to a +4dBm output capable of driving balanced or
unbalanced lines of600 ohms or greater line impedance.
The UB400 is a uni -directional four-channel interface that converts four
IHF level
signals
into four balanced professional outputs. The UB400 is particularly useful in
protecting the four, eight or sixteen main or monitoring IHF outputs of low cost mixers
and tape decks. The UB400 is also a very low cost way to interconnect two CO
players into a balanced system.
The BU400
is also a uni -directional four channel interface but it converts four
balanced professional Signals into IHF levels suitable for feeding the line inputs of
a multi-channel tape deck,
OAT machine or mixer.
Several of these
can comfortably share a single external WA 100, 24VOC I 400mA.
wall-mount AC/OC power supply. Battery packs for remote or back-up use are
planned for this product line. Check your dealer or a current price list for availability.
Up to three of these products will mount side-by-side in only one rack unit using the
available rack mounting
kits. They may also be neatly stacked or mounted side-by-
side
on your desk with the available angled desk mounting kits.
The
B1100, UB400 and BU400 use rugged XLR type connectors for the balanced
inputs
and outputs. Gold plated RCA type jacks mate to the IHF world.
Audio Technologies Inc. 1 154 Cooper Road #9021 West Berlin, NJ 080911 Voice 856-719-99001 Fax [phone] WINW.rn:i1audio.com

CIRCUIT DESCRIPTION
INPUT STAGES
The balanced input stages
of the BU400 and BI100 utilize a FET input LF347 quad
op-amp
in a clean, quiet inverting instrumentation amplifier configuration. Input levels
up to +24dBm will be handled without clipping, excess levels cause only clean
clipping without hang-up or phase reversal. Equal gains from both
HI and LO inputs
allow unbalanced sources to be easily accommodated. Bridging impedance is a high
40Kohms with good CMR.
LEVEL CONTROLS
Each IHF and balanced output
is controlled by its' own front panel potentiometer.
These controls are factory set for standard IHF level
of -10dBu (.25V) and Pro level of
+4dBm.
LINE OUTPUT
Balanced output stages
of the BI100 and UB400 utilize a unique active balanced
output driver IC, the SSM2142, which senses whether the connected load is
balanced and floating
or is unbalanced due to either side being grounded. A balanced
output load will be driven with equal and antiphase levels
on the HI and LO output
lines. An unbalanced (one side grounded) load will cause the driver
IC to shut off the
signal output to the grounded side
of the load and double the output level applied to
the other side, thus maintaining equal output to either type
of load. The output stage
will drive loads
of 600 ohms and higher. Nominal output is +4dBm with clipping at
+22dBm into balanced loads. Maximum output at clipping is reduced by 6dB when
driving
an unbalanced load, since the full output swing of only one driver is available.
POWER SUPPLY
Requires 22 to 30VDC and are designed to share a common external 24VDC 'Wall
Wart" type power supply. A pair
of loop-thru DC connectors on the rear of each
module permits several units to be daisy-chained with P/N20602-1
DC power cables
to a single WA100-1 power supply. The WA100 is a 400mA supply. The BI100 and
the UB400 each draw 70mA and the BU400 draws 40mA. Any combination, which
adds up to less than 400mA, can be powered by a single supply. They incorporate an
"artificial ground" power supply splitting circuit to track the DC input voltage and
provide a center point voltage reference for the audio stages.
Audio Technologies Inc. I 154 Cooper Road #9021 West Berlin, NJ 080911 Voice 856-719-9900 I Fax [phone] www.rzll)audio.com

INSTALLATION
UNPACKING
Inspect the equipment. Ifthere is any visible damage to the unit or to the box it came
in, contact the factory but do not return anything to ATI without prior authorization and
shipping instructions. It may be necessary to have the shipping company inspect the
unit
and the box at your location. Count the pieces! Don't throw out the boxes and
packing material until you are sure you have everything that is coming to you. They
need either their own separately ordered WA100 power supply or a DC cable,
P/N20602-1 to share the supply ofanother.
Rack
and desk mounting hardware may be packed in with the unit even though
ordered separately. Wall mount power supplies must be ordered separately but may
either
be included with the unit or shipped in their own box.
MOUNTING
Single desk mounting kits consist of a pair of angled base plates that mount under
the lower front and rear cover screws of a single unit, to raise
and to tilt it for easy
use.
In addition, one or more sets of vertical stacking plates, mounting to the upper
front
and rear cover screws of the bottom unit, allow multiple units to be stacked.
Several units
can be desk mounted side-by-side and even stacked side-by-side using
horizontal joiner kits together with mounting base
and stacker kits. P/N20617·501 is
the angled base kit. P/N20617-502 is the base plus one stacker kit (two high).
P/N20617-503
is the base plus two stackers (three high). P/N20617-504 is the
stacker kit
by itself and P/N20604-504 is a horizontal joiner kit. Rack mount system
21075-501 mounts three units
in one rack.
Their interfaces are light enough that they can also be attached directly to the
equipment they are interfacing using either Velcro or duct tape.
WIRING
AUDIO CONNECTIONS
XLR type inputs and outputs are wired per figure 1 with pin 2 as HI and pin 3 as
LOW. Pin 1 is the cable shield and ground connection. Pin 1 is grounded as shipped
but may be 'floated to interrupt a hum producing ground loop by opening the unit
and
clipping out the GND LIFT jumpers.
Active balanced outputs and inputs require a reference ground connection to the
source or receiving device for proper operation. The rack frame or a studio buss
connection
can provide this ground if the output cable shield does not carry it
through.
Audio Technologies Inc. I 154 Cooper Road #9021 West Bertin, NJ 080911 Voice 856-719-9900 I Fax [phone] www.Mi1audio.com

GROUNDING
Operation in high RF broadcast environments requires special attention to grounding
and shielding. The chassis must be grounded directly to a good, low impedance
studio ground system. Input
and output connections must be properly shielded and
free of ground loops. It may even be necessary to add shielding to the DC input leads
to avoid RF pickup.
POWER DISTRIBUTION
Sharing a single wall-wart power supply should be looped through each other using
the
DC interconnect cables P/N20602-1. Noise performance of the units can be
degraded by poor DC ground connections between units sharing a common supply,
use of the recommended rack
and desk mounting kits will assure a good ground
connection between units
by firmly strapping their chassis together. CAUTION! The
outer shell of the
DC interconnect cables is positive relative to the chassis. Do not
allow a
DC cable plugged into a powered unit to hang loose where it might short
against the chassis or rack frame.
OPTIONS
230VAC
Contact factory or your local distributor regarding availability of power modules for
operation
in areas outside ofthe U.S.A.
Battery Operation
Battery pack power modules are planned for future inclusion in this product line.
Check a current price list, contact the factory or ask your dealer for availability.
MAINTENANCE
There is no routine maintenance required for this product. If you have a problem,
check panel
LED indicators to assure that the units have DC power, eliminate by
SUbstitution input and output cables, connectors, downstream devices, DC
interconnect cables and Wall Wart power supplies. If you are still experiencing a
problem, call
us and ask for technical support.
POWER SUPPLY LEVELS
The recommended loaded DC input voltage range is 22VDC minimum to 32VDC
maximum over the full range of
AC line voltage tolerances. The audio circuits
continue to work with reduced headroom below 22VDC. Momentary surges
up to
36VDC will cause some increased internal heating, but above 36VDC, IC's
man fail.
Audio Technologies Inc. I 154 Cooper Road #9021 West Ber1in, NJ 080911 Voice 856-719-99001 Fax [phone] www.rnTIaudio.com

OPERATING POINTS
An internal reference voltage equal to 1/2 the supply voltage is generated. All audio
stage
IC inputs and outputs should show a DC level equal to this voltage when
measured with a high impedance meter. Audio inputs and outputs are capacitor
coupled and ground referenced.
PERFORMANCE SPECIFICATIONS:
BALANCED TO UNBALANCED AND UNBALANCED TO BALANCED
Gain:
Nominal Levels:
Peak Levels:
Noise 20kHz B.W.:
Harmonic Dist.:
Frequency Resp.:
Crosstalk:
Input Impedance:
Output Impedance:
maximum
Dimensions:
Connectors:
Power:
Models Available:
-14db nominal, -8db maximum. +14db nominal, +22db
maximum. User adjustable for -10dBu (.25V) User adjustable to
0, +4 or +8dBm output with 0, +4 or +8dBm inputs output with -
'IOdBu (.25V) input.
+4dBm input, -10dBu (.25V) out
-1 OdBu (.25V) in, +4dBm out
+22dBm
in, +8dBu (2.0V) out +8dBu (2.0V) in, +22dBm out
-90dBu maximum output -80dBm maximum output
.02% Max at Peak Level .02% max. at Peak Level 20Hz to
20kHz .005% max. at Nominal Level .005% max. at Nominal
Level
+.25dB, 20 to 20,000Hz +.25dB, 20 to 20,000 Hz
70dB minimum at 10kHz 70db minimum at 10kHz
Balanced, 20kohm bridging Unbalanced 10,000 ohms
Unbalanced, 1500 ohms max. Zs. Balanced, 40 ohms
1.5"H
by 5.5'W by 5.75"0; Weight: 1.5 Lbs. Net
XLR (balanced input/outputs) & RCA phono jacks (unbalanced
input/outputs)
24VOC @ .07A -BI100 & UB400, 24VOC @ .04A -BU400,
Connector sleeve is positive.
BI100 -Bi-Oirectional Stereo IHF to PRO
UB400 -Uni-Oirectional Quad IHF to Balanced
BU400 -Uni-Oirectional Quad Balanced to IHF
Audio Technologies Inc. 1 154 Cooper Road #9021 West Berlin, NJ 080911 Voice 856-719-99001 Fax [phone] www.r.::.lIIaudio.com

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Power Supplies:
WA100-1
WA100-2
BBU100-1
DC100-1
20602-1
Desk Mount Kits:
Rack MountSystem:
All units require 24VDC power supply, which is ordered
separately. They can share a single supply-using loop thru
DC
cable (P/N 20602-1). Do not exceed rated supply current.
Wall mount power supply (UL), 24VDC @ .4 amp, 115 VAC/60
Hz.
Tabletop power supply, 24VDC @ .4 amp, 230 VAC/50-60 Hz
with IEC 320 male 3 pin AC input connector. User supplies
matching AC line cord for local power system.
Battery Pack unit houses four 9V alkaline batteries (batteries
not included). Normal 4 hour life.
DC to
DC converter powers several units from 12VDC mobile
and belt pack batteries. Supplies 24VDC @ .2amp maximum.
DC power cable assembly for looping the DC power
20617-501 Angled Desk Mount Base
20617-502 Angled Desk Mount Base and One Stacker
(2 units
high).
20617-503 Angled Desk Mount Base and Two Stackers
(3 units
high).
20617-504 Stacker (2 units high).
20604-504 Horizontal Joiner (2 units side-by-side). Rev B 9/94
21075-501 Mounts three units in one rack.
Audio Technologies Inc. I 154 Cooper Road #9021 West Berlin, NJ 080911 Voice 856-719-9900 I Fax [phone] www.rzrrJaudio.com