Yibbox is a simple device that can be used to check out suspect signal paths in any kind of audio installation. In the main, it functions as a signal source and is used to substitute for the microphone or line-level source in the failed system. It generates a 400Hz test tone at four different signal levels (0dBm, -20dB, -30dB and -50dB) and also includes a built-in electret mic capsule, enabling the test engineer to communicate with the main monitoring system. Two green LEDs confirm the presence of phantom powering (from 9-48 volts) and the whole thing is powered by a single PP3 battery which provides approximately 24 hours of operation.

The unit itself is about the size of a pack of playing cards and has both balanced jack and balanced XLR outputs. A red LED comes on when the unit is activated and a row of three miniature toggle switches facilitate selection of microphone or tone source, Off, and the various output levels. There are two attenuator settings at -20dB and -30dB, which may be cascaded to give -50dB if required. The tone frequency of 400Hz was chosen so as to be easily discernible from the standard series of test tones. A sprung metal clip allows the Yibbox to be clipped to a pocket.

The unit functions exactly as stated in the instructions, though you do need to be careful to switch in the attenuators when checking a mic circuit if you don't want to give your monitors a nasty surprise. As you might expect, the sound quality of the internal mic is pretty nasty and the unit has a tendency to feed back badly if used close to the speakers, but then it was designed to find faults, not to sing through! This is one of those units most people never tend to consider buying, and then the day comes when one could save your life — metaphorically speaking. It really does make signal tracing simple and could save frustration and embarrassment when something goes wrong in the middle of a busy session.

Further Information
Yibbox £49.95 including VAT.

Cyclone Systems Ltd, (Contact Details).