Rolls MB15b ProMatch Stereo Signal Converter Direct Box

Essential for musicians looking to connect speakers to DJ mixers, this direct box from Rolls features stereo level control for each channel.

The Rolls MB15b - Stereo Signal Converter - is essential for connecting the XLR balanced inputs of powered speakers to the -10 dB unbalanced RCA outputs found on most DJ mixers and controllers. The Rolls MB15b converts the stereo signal to balanced XLR at hot +4dB professional levels so you can run long lines to the powered speakers, with no line loss, interference or noise, and you get a gain boost as well. Stereo volume controls for fine tuning and matching levels. Two-way operation also converts stereo XLR balanced to stereo RCA unbalanced output. Active circuit for signal boost, ships with power supply.


- Stereo Direct Box
- Stereo RCA to stereo XLR
- Stereo Level control for each channel
- Works as stereo balanced line level control
- 1/8 in. Headphone level to line level adaptor

- Max Out:
- Balanced: +18 dB
- Unbalanced: +12 dB
- Max In:
- Balanced: +22 dB
- Unbalanced: +22 dB
- Input Impedance:
- RCA: 100k Ohm
- XLR: 10 k Ohm
- 1/8 in. stereo: 10k Ohm
- Output Impedance: RCA: 100 Ohm, XLR: 100 Ohm balanced
- Noise Floor: -88 dB
- Gain:
- +4 dB In: -8 dB
- -10 dB In: + 20 dB
- THD: .003%
- Power: 12 VDC adapter (center negative)
- Size: 4.15 x 2.46 x 1.55 in.
- Weight: 1 lbs. (.45 Kg)
- Current drain: 16ma nominal no load 15vdc
Dimensions and Weight in Packaging
Base Item
Shipping Weight: 1.25 lbs
Shipping Dimensions: 8 x 5 x 3 in
Manufacturer Part Number (MPN): RLL MB15B

For support or warranty questions, please contact the manufacturer:
Phone: 801-263-9053

Reviewers gave this product an overall rating of 5 out of 5 stars. (2 ratings)
Submitted January 21, 2014 by Anders L in portland, OR
"Rolls MB15b ProMatch Stereo Direct Box"
Overall: 5 out of 5 stars
(see rating details)
Verified Customer zZounds has verified that this reviewer made a purchase from us.
I got this to hookup my laptop to my studio monitors that needed balanced inputs. It works great and is small enough to hide out of sight.
Musical Style:
Electronic Music
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