
Stage Series
Made in Taiwan
Index
Overview
USER GUIDE
SDI-1
Features
Audio Connection
Various Instruments/Device
Connection
Input PAD Attenuation
Eliminating Hum and Buzz and the
Ground Loop
Specications
Measurement
Unika Electronic Co., Ltd.
www.unikapro.com
6F, No.168, Xin-Hu 2nd Rd.
Nei-Hu District, Taipei City. 11494.
Taiwan, R.O.C.
+886 2 27933017
+886 2 27928264
info@unikapro.com

UNiKA SDI-1
User Guide
OVERVIEW
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.
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.
info@unikapro.com
If you need further information, please email us and we will do our very
best to help.
FEATURES
• Single-channel, high-impedance, direct input for an electronic musical
instrument or line-level audio source from a music player or computer.
• ¼“ TS LINK socket. A parallel-wired connector which feeds the direct input
signaltoanotherdestinationsuchasinstrumentamplier.
• Selectable, 3-step attenuator acting on the high-impedance (hi-Z) direct
input signal.
• Single-channel XLR. A transformer-isolated, balanced, low-impedance
(low-Z) output.
• Ground lift switch acting on pin-1 of the balanced output.
1

UNiKA SDI-1 User Guide
① ② ③
④ ⑤
①
¼“ TS LINK socket: a parallel-wired direct feed from the input. It can be
linkedtoinstrumentamplier.
②
High-impedance direct input with Combo jack: connect to output of electronic
musical instrument or audio device using XLR or TRS, TS jack plugs.
③
Input PAD: 0dB, -20dB & -40dB selectable 3-step attenuator reduces the
input sensitivity to prevent overload.
④
GGround lift switch: lifts the pin-1 on the XLR output connector to help
eliminate hum and buzz caused by ground loops.
⑤
Balanced XLR output: low-impedance output with isolation transformer.
2

UNiKA SDI-1
User Guide
AUDIO CONNECTION
Instrument Direct input & Parallel Link connection
As with all audio gear, always ensure audio system levels are turned down
or equipment turned off before making connections. This will avoid plugin or turn-on transients from damaging more sensitive components such as
tweeters.
There is one channel on the SDI-1, featuring an XLR- ¼“TRS Combo jack
INPUT, a ¼“ TS parallel LINK output and a balanced XLR OUTPUT.
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. Keeping unbalanced cables under
8 meters (25 feet) in length is good practice while balanced cables can
easily extend to 100 meters (300 feet). 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.
Female Male
XLR-TRS Combo input
2 1
Fig-1: XLR Plugs Balanced
For Unbalanced connection, pin-3 should be connected to Ground with pin-1.
1
3 3
connection:
1-Ground
2-Signal Hot (+)
3-Signal Cold (-)
2
3-Signal Cold -
Fig-2: XLR-¼"TRS Combo
socket for direct input
1-Ground2-Signal Hot +
3