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  • Radial Engineering EXTC Guitar Effects Interface

    By Phil O'Keefe |

    Now you can use your effects pedals with anything!

    By Phil O'Keefe

    5329f41fe1094.jpg.1f6a8833a37da680da1924050cecd490.jpgThe first time I tried using a guitar effects pedal on a vocal mic while recording (way back in the 1970s), it didn't go very well. At the time, I didn't have a full appreciation of the importance of impedance and the different levels involved, and as a result, the sound quality was far less than I was expecting. Additionally, ground loops can also be troublesome issue when attempting to use pedals with studio gear. It can also be tricky to get just the right balance of dry and effected signal. Solving the problems of interfacing effects pedals with the rest of your studio setup is exactly what the Radial EXTC Guitar Effects Interface was designed to do. Let's take a closer look.

    What You Need To Know

    • Packed into a standard single space 500 series module, the Radial EXTC slipped right into my Radial SixPack rack / power supply with no muss or fuss. The fit was perfect, and while I didn't try it with any other rack, I saw nothing that would suggest it would't work equally well with a third-party's 500-series rack unit as the host.
    • The line input and line output connectors for the module are provided by whatever 500-series rack unit you have it installed into. The EXTC 500 supports balanced line in and out.
    • The Radial EXTC isn't a power hog - which can be a big consideration with some 500-series racks. The power requirement is a measly 60mA, so it's well within the recommended specs, even for rack units with less power on tap than the Radial SixPack, which has 265mA available per slot.
    • Connecting your external effects is easy. Two front panel 1/4" jacks are provided; one for sending the signal out to your effects (or amp), and one for returning the signal from the effects pedal(s). Each jack has a corresponding level control, allowing you to set the send and return ("receive") levels to optimize signal to noise. This effects loop is designed for use with high impedance effects, so there's no need to worry about impedance matching when connecting your various guitar pedals to it, and while you can fine-tune the levels going to your pedals and coming back from them, the EXTC drops the line level to the appropriate range for use with effects pedals.
    • It can also be used as a more conventional "Reamping" device, and works great when sending a line output signal from your DAW or tape deck straight into a guitar amp.  
    • The EXTC's effects loop includes an isolation transformer to prevent ground loops.
    • The EXTC uses a Class A discrete transformer coupled circuit for low noise and great sound.
    • When used with any of the Radial Workhorse rack units, the rack's Omniport jack is supported by the EXTC 500. The EXTC provides a second unbalanced effects loop in series after the front panel loop via the Omniport jack. This insert loop uses a TRS jack (wired tip send, ring return, sleeve ground) and is optimized for use with studio / rack effects units, and can be engaged or bypassed with a front panel switch.
    • The remaining controls on the EXTC are fairly straightforward. At the top of the module is a Blend knob that allows you to set the ratio of the dry (line input) source sound and the effects loop. This is extremely handy, and allows you to use the EXTC while tracking to add just the right amount of dirt and grit to a track from a distortion or overdrive pedal, or to adjust the balance of dry and ambient signal when using delay or reverb pedals when recording.
    • Of course, nothing says you can't process a pre-recorded signal. Just send the pre-recorded track from your DAW to the EXTC, patch some pedals into it, and then send the line output from your 500 series rack to a new track in your DAW and "print" the 100\% wet signal from the effects pedal(s), and adjust the balance of the wet and dry tracks later, at mixdown.  
    • Since some pedals invert the signal polarity, a 180 degree polarity reverse switch is also provided. This is also a very useful feature, especially when using the Blend control. If you notice things starting to sound weak, thin, or hollow when you start to blend in the effected signal, hitting this button will usually eliminate the phase cancellation and fix the problem.   
    • You can also use the Radial EXTC as a direct box by plugging your guitar or bass directly into the Receive jack and using the line output from your rack to feed an input on your recorder or interface.  
    • The sky's the limit with the EXTC - literally any line level signal - either from a live sound source (line level out from your mic preamp, keyboard, etc.) or pre-recorded track can be processed with your effects pedals when you have this handy box in your 500-series rack. Wah on piano, fuzz on drums, phaser on vocals - you really are only limited by your imagination and musical tastes.


    • The EXTC is a mono unit, so if you're working with stereo signals and stereo effects pedals, you'll need two EXTC units.
    • There are no meters on the EXTC, nor on most effects pedals, so you'll have to use your ears to determine when the signal to noise ratio is optimized.


    I love devices that are well-built, affordable, sound great, and that allow you to get a ton of cool new sounds from other gear that you already own, and that let you apply that gear in new and creative ways - and that's exactly what the Radial EXTC 500 does. The Radial EXTC encourages creative experimentation, and you're bound to come up with your own unique and individual tones when you use this box. As is typical with Radial equipment, the EXTC solidly built, and exceptionally well thought out, and it provides the user with all the tools they need to use effects pedals when tracking, reamping, or when mixing. It's a ton of fun to use too; all of which makes it a must-have for 500-series rack owners. 


    Musician's Friend's Radial Engineering EXTC 500 Reamp Guitar Effects Interface online catalog page ($300.00 MSRP, $249.99 "street")

    Radial Engineering's EXTC 500 Guitar Effects Interface web page

    Radial Engineering EXTC introduction video:



    5329f41fe8d96.jpg.68b8f8fab2723f62d1b85deeccf00017.jpgPhil O'Keefe is a multi-instrumentalist, recording engineer / producer and the Senior Editor of Harmony Central. He has engineered, produced and performed on countless recording sessions in a diverse range of styles, with artists such as Alien Ant Farm, Jules Day, Voodoo Glow Skulls, John McGill, Michael Knott and Alexa's Wish. He is a former featured monthly columnist for EQ magazine, and his articles and product reviews have also appeared in Keyboard, Electronic Musician and Guitar Player magazines. 

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