Rolls ADB2 - Manual

ADB2

Active Direct Box

Owners Manual

ADB2 Active Direct Box

• Uses standard 9 - 48 volt phantom

power for supply

• Ground Lift for "hum" reduction

• Attenuator switch for connection to line

level or speaker level signals

The ADB2 is an active direct box for convert-

ing a high impedance signal such as a direct

out from a bass amplifier, to a low imped-

ance signal such as a snake input and a

mixer's microphone input. The Ground Lift is

provided to reduce possible ground hum or

buzz.

Rolls Corporation

Salt Lake City, UT

3/01

SPECIFICATIONS

Input Level:

-10 to +40 dB unbalanced

Output Level:

-10 to +2 dB balanced XLR Male (pin 2 +)

Bandwidth:

1 Hz to 50 kHz

S/N Ratio:

100 dB

Jacks:

(2) 1/4" phone, (1) XLR male

Controls:

Attenuator switch, Ground Lift switch,

Power:

9 - 48 VDC Phantom Powered

Size:

2" x 3.5" x 5"

WARRANTY

For information on the Rolls One

Year Limited Warranty, and to reg-

ister this product, visit our website

at

www.rolls.com

1

29-Mar-2001

Date:

Rev:

A

Sheet 1 of

Ba

3

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2

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Size:

Document Number:

ADB2.SCH

PHANTOM DIRECT BOX

ROLLS CORPORATION

5968 South 350 West

Salt Lake City, UT 84107

Congratulations and thank you for your purchase of the ADB2 Active Direct Box. The

ADB2 is intended for sending unbalanced signals (up to +40 dB) to a mixing console

or other professional input device. The unit has no transformer, so stray field pickup is

nonexistent. The ADB2 is powered by standard microphone phantom power from 9 -

48 VDC and uses discrete low-noise differential drivers to make it very quiet. The unit

has two 1/4" input jacks wired in parallel, a male XLR output jack, a ground lift switch,
and a three-position attenuator switch.

DESCRIPTION

INPUTS: Two 1/4" unbalanced jacks - wired together in parallel. For connection to line

or instrument level signals.

OUTPUT: One male XLR jack for connection to mixing console or other input device

carrying phantom power.

ATTENUATOR SWITCH: Decreases the input signal by the indicated amount. At 0

dB the signal is not attenuated, at the 20 and 40 dB settings, the signal is dropped by

that amount.

GROUND LIFT: Removes the ground connection of the 1/4" and XLR jacks from the

chassis ground.
ACTIVE LED: Indicates the unit is receiving phantom power.

INSTALLATION

In order for the ADB2 to function it must be connected to a microphone phantom

power source with a balanced XLR cord. The input may be anything from a speaker

source such as a music amplifier, VCR or projector, to an instrument such as a guitar

or High-impedance microphone. Care should be taken to overdrive the ADB2 or there

will be a distorted sound from the unit. Use the lowest attenuator setting that gives

distortion free sound. The ground lift switch should be in the position that yields the

lowest noise.