Radial SGI TX/RX Studio Guitar Interface 1-Channel Active DI Box


95 out of 100. Incorporating 80+ ratings and reviews.

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Radial SGI TX/RX Studio Guitar Interface Active DI Box

Unlike most other boxes, the Radial SGI system comprises a Transmitter (TX) and a receiver (RX).

If the musician has to be far from the amplifier, like with being in the control room while the amplifier is in a separate live room, the signal going to the amplifier must be pristine and free from the high frequency roll off of capacitance.

While DI boxes are used to create a high-fidelity, low noise, balanced signal into an interface or mixer, the SGI is meant to preserve tone and fidelity up to 330ft.

This means you can also use the SGI as a signal preserve when sending your guitar's tone to an off-stage amplifier.

The proprietary Drag control allows you to tweak the load on your signal chain to compensate for different pedals, buffers, or cables.


  • SGI-TX hi-Z input: 1/4" jack (buffered) with Drag control load correction circuit
  • SGI-TX output: Balanced XLR-M output
  • SGI-RX input: Balanced XLR-F input
  • SGI-RX hi-Z output: 1/4" jack
  • Ground lift
  • Weight: TX - 1.1 lb; RX - 1.1 lb


Several users who perform live say this is the best way to run an amp off stage with little signal loss from capacitance. Some studio engineers also have this integrated into the construction of their studio space to run an amp completely isolated in a different room so that the musician can stay in the control room. There are "hacks" available to simulate the setup, but community discussions say they are not as efficient or cost effective as just getting an SGI.


No reported cons except for improper usage of the system like using only one or the other box as a solo DI box.


The Radial SGI is a very specific tool for a very specific problem: cable capacitance over long distances on the stage or in the studio while going to an amplifier. Get it if you have a large studio setup with separate control and live rooms and want to preserve your tone better; or if you perform on stage with a guitar amplifier miked up in the back. Steer clear if you need -just- a DI box.

Although this was previously on our recommended list, there are now more highly rated options available which you can see in our guide to The Best DI Boxes & Reamp Boxes.