The UNiKA SDI-2 is an easy-to-use, dual-channel, passive direct box for musical instrument and audio system applications. In addition to a high-quality audio transformer, the SDI-2 has some very useful built-in features. So please take a few minutes to go through this user guide to ensure you take full advantage of the facilities on offer and get the best possible result.
Instrument Direct input and Parallel Link connection
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. Unbalanced cables are much more susceptible to noise than their balanced counterparts. The balanced output of the SDI-2 is mic level, meaning that it should be connected to the mic input of a mixing console or mic preamp.
Input pad attenuation
The optimal setting for this is most likely with the pad switch set to 0dB, although with some high-output pick-ups the performance of the direct input may be improved if the pad switch is set to -20dB to prevent possible clipping of the input signal.
The direct input can also be fed either from a line-level output from the head-amp (pad set to -20dB) or from the head-amp speaker output ( pad set to -40dB). The PAD setting applies to both inputs.
Eliminating hum and buzz and the ground loop
The SDI-2 is equipped with output isolation transformers to eliminate hum and buzz caused by stray DC voltage and ground loops.
The independent Ground Lift switches on the outputs 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.
- Input connectors: 2 Unbalanced combo jack (Pin-2 hot, Pin3&1 ground)
- Link connectors: 2 Unbalanced phone jack
- Input pad switch: 0dB/-20dB/-40dB
- Input impedance: 1MΩ/47KΩ/47KΩ
- Max. input level before clipping: +26dBv
- Output device: 2 XLR w/balance transformer isolated
- Output impedance: 600Ω nominal, Transformer balance
- Output level: +26dBv
- Frequency Response: 20Hz to 20KHz +0.2 / 0 dB
- Dynamic range: >109dB
- S/N ratio~ un-weight 20Hz to 20KHz: -131.8dB
- T.H.D~ 1KHz, 0dBv output: < 0.0002%
- Ground/Lift switch: Lift pin-1 on XLR outputs, separate
- Construction: 1.6/1.2mm steel cabinet & chassis
- Surface finished: Durable powder coating
- Dimension(WxDxH): 124 x 78 x 46mm
- Weight: 0.5Kg