PRO 3SP is a passive one-input and three-output isolated signal splitter without the need to install batteries or provide phantom power.

PRO 3SP has a pair of built-in UNiKA-PROTM EI30A10E 1+1:1+1 isolation transformers, which has a special copper foil layer and a dedicated ground layer, which allows this device to restore high signal/noise ratio and dynamic sound, and can avoid unnecessary Leakage caused by radio frequency interference, ground interference and potential difference. PRO 3SP is particularly suitable for recording studios, live performances and fixed installation projects.

PRO 3SP’s input uses XLR balanced sockets, suitable for inputting LINE signals. The XLR balanced sockets output by MONITOR are parallel and straight through without isolation transformers; CH-1/CH-2 output channels each have independent UNiKA-PROTM isolation transformer and shared GND/LIFT switche for easy connection to remote or different power sources at the end of the equipment to eliminate the leakage and noise caused by the potential difference and the ground loop.



PRO 3SP’s CH-1/CH-2 are each equipped with independent EI30A10E professional audio isolation transformer, which is a transformer that works in the audio range, also known as a low-frequency transformer. The frequency range is generally from 20 to 20000 Hz. It is mainly used for audio transmission between systems or devices. It can completely isolate the potential difference between two systems, avoid hum interference caused by ground loop problems, and prevent excessive potential difference from damaging the input level of the device. The safe transmission of signals is an essential product for long-distance transmission of analog audio systems.

However, since it does not have an input amplifier circuit and attenuator, it can only transmit balanced signals through an isolation transformer or convert unbalanced signals into balanced signals for transmission, and does not have the function of increasing the level. If the input signal is of a high-impedance type, such as musical instruments or some players, it is recommended to use other DIs with input attenuators in the PRO series to transmit signals. These DIs also have a built-in EI30A10E professional audio isolation transformer.

The MONITOR output of PRO 3SP is paralleled from input without isolation transformer, usually used in near-end equipment, such as the connection between stage monitor console and active stage monitor speakers.

In an analog system, PRO 3SP is equivalent to a multipoint signal distributor, which can distribute the signals on the stage to the stage monitor mixer , F.O.H. console and production console. Or in fixed installation applications, you can use it to distribute signals to different areas or rooms.


.One input & three output audio splitter
.CH-1/CH-2 are equipped with separate UNiKA-PROTM EI30A10E isolation transformer
.Use XLR jack for input
.Set the direct output of MONITOR OUT without isolation transformer
.The output is equipped with a shared GND/LIFT switch

Circuit principle Passive/Transformer balance output
Input connector 1 x Female XLR
Monitor out connector 1 x Male XLR without ISO Transformer
Input impedance 4.7KΩ
Output impedance 50Ω 
Max. input level before clipping +22dB 
Max Output level +22dB 
Output connector 2 x Male XLR through ISO Transformer
Output GND/LIFT switch Shared push button 
Frequency response 20Hz-20KHz, -0.3/+0.1dB
S/N ratio @20Hz~20KHz un-weight >120dB 
T.H.D. @1KHz 0dBV output <0.02%
Transformer Ratio 1:1+1:1
Chassis 1.6mm/1.2mm steel cabinet and chassis
Surface finished  Durable complex painting
Dimension (W x D x H) 78 x 124 x 46 mm
Weight 0.62Kg
Shipping weight 0.65kg 
Packing per carton 20pcs/13.60Kgs 
Shipping dimension per carton 305 x 283 x 195mm