UNIKA SD-1
The UNiKA SDI-1 is an easy-to-use, single-channel, passive direct box for musical instrument and audio system applications. In addition to a high-quality audio transformer, the SDI-1 has some very useful built-in features.
Connect your source instrument or audio device to the input and the balanced XLR output to the mixing console. The LINK connector output provides the means for connecting the signal to an instrument amplifier or personal monitor system. The balanced output of the SDI-1 is mic level, meaning that it should be connected to the mic input of a mixing console or mic preamp.
The SDI-1 has one channel with an XLR ¼"TRS combo input, a parallel ¼"TS-LINK output and a balanced XLR output.
The most common use of the direct input is with guitar pick-ups, keyboards or audio devices like CD players, computers etc.
The SDI-1 is equipped with output isolation transformers to eliminate hum and buzz caused by stray DC voltage and ground loops. Computers, CD players and other consumer equipment can be noisy – this is particularly true when incorporating audio with a projector – so isolation transformers can be very useful when combating system noise. The Ground Lift switch on the output takes this one step further by lifting pin-1 on the XLR. Computers are often the source for noise problems in audio systems, so greater care is certainly needed to keep things quiet.