
Redbox RB-BL4
August 2008
www.sonifex.co.uk
t: +44 (0)1933 650 700
f: +44 (0)1933 650 726
sales@sonifex.co.uk

AUDIO INTERFACES
Tel: +44 (0)1933 650 700 Fax: +44 (0)1933 650 726 Email: sales@sonifex.co.uk Internet: www.sonifex.co.uk
Redbox - Matching Converters
RB-BL4 Dual Stereo Bi-Directional Matching Converter
The RB-BL4 is a dual bi-directional stereo
unit for interfacing domestic or semi-pro
unbalanced equipment to professional
balanced line levels, and vice versa.
The four XLR-3 electronically balanced
inputs have an impedance of 20kΩ bridging
and are routed to four unbalanced RCA
(phono) outputs with an output impedance
of <50Ω.
MATCHING CONVERTERS
The four RCA unbalanced inputs have an
impedance of 20kΩ and are routed to four
balanced XLR-3 outputs with an output
impedance of <50Ω. All connections are on
the rear panel.
The output gain can be adjusted for
left and right channels by using pre-set
potentiometers accessible through the
rear panel.
Audio Specication For RB-BL4
Maximum +28dBu
Input Level:
Maximum +28dBu
Output Level:
Input >10kΩ unbalanced
Impedance (RCA):
Input >20kΩ balanced bridging
Impedance (XLR):
Output <50Ω
Impedance (RCA):
Output <50Ω
Impedance (XLR):
Distortion: 0.01% THD @ 1kHz, ref +8dBu output
Noise: -100dB, unity gain, ref +8dBu output
Common Mode >66dB typically
Rejection:
Frequency 20Hz to 20kHz ±0.1dB (600Ω load,
Response: ref 1kHz)
Gain Range: Unbalanced Output : -28dBu to
0dBu, ref 0dBu into balanced XLR
input
Balanced Output : -15dBu to +15dBu,
ref -15dBu into unbalanced RCA input
Connections
Inputs: 4 x RCA phono (Unbal), 4 x XLR 3 pin
female (Bal)
Outputs: 4 x XLR 3 pin male (Bal), 4 x RCA phono
(Unbal)
Mains Input: Filtered IEC, switchable 110-120V, or
220-240V, fused, 6W max
Fuse Rating: Anti-surge fuse 100mA 20 x 5mm
(230VAC)
Anti-surge fuse 250mA 20 x 5mm
(115VAC)
Equipment Type
RB-BL4: Dual stereo bi-directional matching
converter
Physical Specication
Dimensions 48cm (W ) x 10.8cm (D) x 4.2cm (H) (1U)
(Raw): 19” (W) x 4.3” (D) x 1.7” (H) (1U)
Dimensions 53cm (W ) x 20.5cm (D) x 6cm (H)
(Boxed) : 21” (W) x 8” (D) x 2.4” (H)
Weight: Nett: 1.3kg Gross: 1.9kg
Nett: 2.9lbs Gross: 4.2lbs

www.sonifex.co.uk
www.sonifex.co.uk
t:+44 (0)1933 650 700
t:+44 (0)1933 650 700
f:+44 (0)1933 650 726
f:+44 (0)1933 650 726
sales@sonifex.co.uk
sales@sonifex.co.uk
61 Station Road
61 Station Road
Irthlingborough
Irthlingborough
Northants NN9 5QE
Northants NN9 5QE
United Kingdom
United Kingdom