ATI Technologies BU400, BU400B, UB400B, BI400 Operating And Maintenance Manual

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. I154

Cooper

Road

#9021

West

Berlin,

NJ

080911

Voice

856-719-99001

Fax

856-719-99031

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 of the 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 of 600 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. 1154

Cooper

Road

#9021

West

Berlin,

NJ

080911

Voice

856-719-99001

Fax

856-719-99031

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. I154

Cooper

Road

#9021

West

Berlin,

NJ

080911

Voice

856-719-9900 IFax

856-719-99031

www.rzll)audio.com