A legend in the pro-audio industry, the BSS AR133 DI Box has been around for many years - partly for its solid, reliable build, but also for its audio performance.
- Rugged aluminium case with polyurethane end-cheeks.
- Battery or Phantom Powered
- Inputs on 1/4" (6.35mm) jack or XLR.
- Link out jack socket for connection to backline amps.
- Input attenuation switchable between 0dB, -20dB and -40dB
- Transformer balanced and isolated balanced output on XLR
- Earth lift switch
So, what is a DI box and why do you need one? Well, DI is an acronym that means 'Direct Injection' their main function is to create a balanced signal out of an unbalanced signal. Unbalanced signals are more prone to induced noise and interference. This problem is increased as the distance the signal travels increases - i.e. the longer the cable run, the more chance of picking up unwanted noise or interference. Balanced signals, on the other hand, are very good at rejecting interference and give much cleaner signals over long cable runs. They utilise a second signal conductor which carries an out of phase version of the signal which is used by the receiving equipment to cancel out any interferenced induced in the cable run.
Now some equipment creates a balanced output signal by default. Microphones (at least all professional ones) do as well as mixing consoles and some musical instruments. Where that is not the case - e.g. guitars, keyboards, laptops, etc, then a DI box can be used to create a balanced signal.
DI boxes can provide a number of other functions. These can include - impedance matching, signal attenuation (PAD), phase reverse and ground isolation (ground lift).