Rolls Satellite TV System ADB2 产品宣传页

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

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"

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

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Size:

Document Number:

ADB2.SCH

PHANTOM DIRECT BOX

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. 

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.

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.