Rolls DB25 - Input and Output Connectivity; Technical Specifications; Performance Metrics

INTRODUCTION
Thank you for your purchase of the DB 25 MATCHBOX, a
passive direct box designed to take high impedance signals
and convert them to low impedance. The unit features an
Attenuator switch for padding the input signal by either 20 or
40 dB, and a Ground Lift switch which may reduce unwanted
hum caused by "ground loops".
DESCRIPTION
Input Jacks: 1/4" unbalanced jacks for receiving line or in-
strument level signals.
Attenuator switch: Reduces the input signal by the amount
indicated.
Ground Lift Switch: In the "Lift" position, the ground connec-
tion of the XLR jack is disconnected from the chassis.
Output Jack: XLR balanced jack for connection to a mixing
board or other balanced input device.
SPECIFICATIONS
Frequency Response: 50 - 15kHz +/- 3 dB
Output Impedance: 600 Ω
Input Impedance: 50K Ω
Max Output Level: +4 dBm
EXAMPLE APPLICATIONS
J1
PHONE 1/4
1
2
3
J3
XLR M PC
T1
50K - 600 CT
8
7
5
6
SW1B
ALPHASW
-20
R1 10K
1
2
4
3
SW1A
ALPHASW
0 Db
J2
PHONE 1/4
-40
R2
100K
R3
1K
1
2
3
SW2A
DPDT
LIFT
Date: December 22, 1992 Sheet of
Size Document Number REV
A DB25.SCH
Title
DB25 MATCHBOX
ROLLS CORPORATION
0 dB
-20 dB
-40 dB
ATTENUATOR
MATCHBOX
DB25
GROUND LIFT
GND
LIFT
IN
OUT
AMPLIFIER
MIXING BOARD
0 dB Setting
BASS GUITAR
0 dB
-20 dB
-40 dB
ATTENUATOR
MATCHBOX
DB25
GROUND LIFT
GND
LIFT
IN
OUT
-40 dB Setting
SPEAKER OUTPUT
0 dB
-20 dB
-40 dB
ATTENUATOR
MATCHBOX
DB25
GROUND LIFT
GND
LIFT
IN
OUT