BSS AR 133 Active Direct Box
The BSS AR133 provides added functionality and enhanced audio performance and was designed to be more affordable for musicians, studios and PA companies.
The unit includes phantom power and battery supplies as standard. Should the phantom power from the console fail or be accidentally switched off, the AR-133 automatically switches over to the internal 9V battery providing uninterrupted use.
The AR133 is housed in a rugged aluminium extrusion case, with robust polyurethane end-cheeks which give the AR-133 a very distinctive look.
Input connectors are both 1/4" jack sockets and an XLR socket, the latter meaning that the AR-133 can be used to convert unbalanced signals to a balanced output on XLRs throughout.
The arched case allows cables to run back underneath the unit from the end for neat cable management.
Input attenuation is 0, -20 or -40dB, making the box suitable for instrument, line or amplifier levels on inputs. On the output side, a ground-lift switch is provided for quick solutions to ground-loop problems.
The AR-133 uses an enhanced version of the same audio path as the AR-116, now regarded by many people as a reference standard. The sound quality is legendary, particularly on acoustic and bass guitars. Numerous applications can be satisfied by the AR-133. For example, as well as the traditional guitar use, the AR-133 can be used with keyboards, DJ consoles, amplifier outputs, and other electronic sources. An additional bonus is the ability to use the AR-133 as an active balancing device.
Why do I need a DI Box?
Signals from electronic instruments such as guitars, keyboards and similar sound sources generally have a low level, high impedance output, which will not interface with the low impedance balanced input found on professional sound mixing consoles. Furthermore these signals cannot be driven up long cable lengths without serious loss of level and degradation.
The DI box converts this signal to a more suitable form without interfering with or modifying the signal at the instrument source, and should provide freedom from ground and power line related problems. Passive DI boxes have limited applications as they will inevitably affect the signal source for guitar type applications, and can also have an insertion loss of around 20dB. The only safe and predictable way to provide direct feeds from instruments or other sources is by using an Active DI box utilizing an input amplifier driving an output transformer.
The AR-133 fulfills all the requirements of an active DI and more.
- Switchable input attenuation
- 0dB for guitar-type pickups
- -20dB for line level signals
- -40dB for speaker feeds
- Matches the level and impedance with unity gain without loading the source
- Can drive signals up long cable lengths
- Powered from console phantom power or internal battery
- Automatic switchover to battery if phantom power fails
- Parallel Link Jack output to feed amplifiers directly
- Parallel XLR input for converting unbalanced outputs to balanced lines
The audio signal path of the AR-133 is an enhanced design based upon the long established BSS AR-116, now regarded by many as a reference unit. The sound quality, particularly on acoustic guitar and bass guitar pick-ups, is recognized as outstanding. The uses, however, are not limited to guitars or keyboards. The AR-133 is suitable for use whenever it is critical to match levels and impedances, sources need isolation or long cables are used. The provision of both 1/4" and XLR connectors on the input further extends the use of the AR-133 with a multitude of source devices.
Powered from the Console or Battery
The AR-133 takes its power either from the standard microphone phantom powering available from the desk, or from an internal 9V battery. When phantom is used, the power led on the AR-133 is lit continuously. If the phantom fails, the battery immediately takes over, with a flashing led showing battery use.
Ground Lift for Solving Grounding Problems
The ground lift switch enables the input signal’s earth to be separated from the output ground, a quick and easy way to prevent ground-loop problems.
Guitar pick-up feed - Suggested Attenuation Setting: 0dB - The low level, high impedance signal from the guitar pick-up is translated by the AR-133 into the high-level, low impedance balanced signal required by the front-of-house console.
Keyboards - Line Level Feed - Suggested Attenuation Setting: 20dB (line level) or -40dB (amp
level) - The line level output of the keyboard is balanced and matched by the AR-133. In multiple keyboard setups where a mixer-amp is used for monitors, the AR-133 can be used to save on DI boxes by taking the output of the amplifier as the interface to the console, rather than using separate DI’s for each keyboard. In this case, either a line output or the speaker output can be used, depending on the mixer/amp.
Speaker Feed - Suggested Attenuation Setting: -40dB - Taking a feed from the amplifier output allows the post-amplifier, post EQ/effects signal to be fed to the console, meaning that a particular effect/amp sound can be sent to the mix.