Radial Engineering EXTC-SA Guitar Effects Interface  From Radial

Process your line level signals with your guitar pedals with this balanced stand-alone audio effects interface from Radial!

Radial Engineering


Retail:  $350.00

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Radial EXTC demo with Joe Chiccacelli

Joe Chiccarelli walks us through a session recording guitar with the Workhorse 500 series frame and mixer. He uses the Radial PowerPre, EXTC, and Komit modules in the session.Joe Chiccarelli is an American music producer, mixer and engineer who has been active since early '80's. He has produced albums by Bon Jovi, Frank Zappa, Tori Amos, Chicago, Poco, Bob Seger, Annie Lennox. He also engineered The Raconteurs "Consolers of The Lonely" for which he received his eighth Grammy award, for Best Engineered Album of 2008.

Manufacturer's Description from Radial

  • Balanced interface for guitar effects pedals
  • Separate send & receive controls optimize signal path
  • Transformer isolation helps eliminate ground loops
  • Creative tool helps your mix stand out from the rest
The Radial EXTC-SA™ is a stand-alone audio interface that lets you incorporate guitar effects into the realm of pro-audio recording. Just imagine… add a touch of grit to a vocal track, some wah on a kick drum, maybe flange a violin…The EXTC is a creative tool made for your esoteric-inventive side, ready to unleash fresh new sounds that will make your recordings stand out from the crowd.
And it's super easy to use: connect a line level signal from the recording system. The EXTC-SA unbalances the signal and converts it to high impedance where guitar pedals can be inserted at will. Simply plug in, turn the track on, set your levels and adjust the blend for just the right amount of magic. Be prepared for instant amazement. Legalized ecstasy.
Features include Radial's award winning 100% discrete class-A guitar buffering for ultimate audio integrity, transformer isolation to eliminate buzz and hum caused by ground loops, 180º polarity reverse to keep effects and balanced signals in phase, and two loops that can let you compare signal paths or combine them to create your magical masterpiece.
The Radial EXTC-SA is without a doubt one of the most innovative effect manipulating devices ever made. And it opens the door to new sounds by taking Reamping™ technology to an all new level.
The EXTC... be prepared for wild & wonderful!
Radial Engineering

About Manufacturer

Radial Engineering is a manufacturer and distributor of professional audio equipment, building tools for the working audio and audio-video professional. Radial is located on the Fraser River, just outside Vancouver, British Columbia in the municipality of Port Coquitlam. The company began operations in the fall of 1991 as the Canadian distributor of Mogami cable and Jensen Audio Transformers. In 1992, it became a limited corporation under the JP Cabletek Electronics Ltd. banner. The Radial name was first used on house branded cables and snake systems. The Radial name and logo represents a cross section of quad cable; Radial being round. In 1996 the Radial JDI direct box was launched. This led the way to the Radial JDV and today, over 50 electronic products are now being produced under the Radial, Tonebone and Forest Audio brands. In 2001, the Primacoustic brand was launched to address the growing demand for acoustic products for the burgeoning home recording market and in 2006, the company officially changed its name to Radial Engineering Ltd.





Circuit type: 

Class-A discrete, transformer coupled

Power requirement:

Radial 15VDC/400mA power supply included






Frequency Response:


Voltage Gain:

20Hz ~ 20kHz ±1.5dB



20Hz ~ 10kHz ±3.5dB(-8dB @ 20kHz)    

12dB - send & receive at max

6dB - send minimum, receive max

0dB - send & receive set at 12 o'clock


<0.005% @ 0dBu 

<0.002% @ 0dBu




Intermodulation Distortion:

<0.003% 0dBu input

<0.02% 0dBu input

Maximum input:




Effects Loop I/O

Send 1/4" output

Receive 1/4" input


Unbalanced ¼"

Unbalanced ¼"


1.5k Ohms

10K Ohms

Gain (Variable)

From -14dB ~ +3dB 
0dB at center point

From -99dB ~ +9dB
0dB at center point

Maximum Gain:



Line Level I/O

XLR & 1/4" TRS Input

XLR & 1/4" TRS Output


Rear Panel Input - Balanced XLR Female & 1/4" TRS

Rear Panel Output - Balanced XLR Male & 1/4" TRS


15k Ohms

200 Ohms




All voltage gain specs with both effect loops bypassed. Insertion of effects units will vary gain somewhat due to their particular input and output impedances.