Radial Engineering EXTC-SA REAMP User manual

True to the Music
www.radialeng.com
®
True to the Music
®
User Guide
EXTC-SA™
EFFECTS REAMPER
www.radialeng.com
Radial Engineering Ltd.
1845 Kingsway Ave., Port Coquitlam, BC V3C 1S9, Canada
tel: [phone] • fax: [phone]
email: [email protected]

Radial®EXTC-SA™Effects Reamper®
Table of Contents ......................................................Page
Feature Set .................................................................... 1
Overview ........................................................................ 2
Getting Started ............................................................... 3
Specications ................................................................. 4
Block Diagram................................................................ 5
Warranty............................................................Back cover
www.radialeng.com
Congratulations and thank you for purchasing the Radial EXTC-SA Effects Reamper®.
The EXTC-SA is a unique interface designed to allow you to introduce high impedance guitar
pedals and effects into the recording world with relative ease while keeping the signal quiet.
With the EXTC, you are set to add wah to a keyboard track, tube distortion to a vocal track or
an envelope lter to the snare drum track. The EXTC is all about creativity and making sure
your recording stands out from the rest.
This manual describes connecting and operating your EXTC-SA. To take full advantage of
the unique features that have been incorporated into the EXTC-SA, please read through this
guide before using it. This user guide will give you a broader sense of the units capabilities.
If you have questions that are not covered in this manual, please visit the FAQ section on
our website. This is where we post answers to questions from users. If you cannot nd the
answer to your question please feel free to send an email to [email protected] and we will
do our very best to respond as quickly as possible.
The Radial EXTC-SA Effects Reamper opens creative options to your recording world.

True to the Music
®
Radial Engineering Ltd. EXTC-SA
1. POWER LED - Indicates when the unit is
powered on.
2. SEND LEVEL - Used to adjust the output
level going to the pedals and optimize signal-
to-noise for best performance.
3. RECEIVE LEVEL - Used to set the effects
loop return level and further optimize signal-
to-noise.
4. 180º POLARITY INVERT - Lets you adjust
the polarity of the wet signal path and bring it
into phase with the dry signal when they are
being mixed together.
5. BLEND - Lets you adjust the wet-dry mix
between the original unprocessed signal and
the EXTC-SA effects loops.
6. LOOPS ON/OFF - Turns the A & B loops on
and off. An LED indicator illuminates when a
loop is active.
1 2 3
9
4
10 12
5
11
6 7
8
1
FEATURE SET
7. BOOKEND DESIGN - Enclosure design
creates a protective zone around the front
controls.
8. POWER ADAPTER - Connection for the
included power supply with handy cable
clamp to prevent accidental disconnection.
9. ¼” SEND and RECV - Separate LOOP-A &
B send and receive jacks used to connect
guitar pedals to the EXTC-SA. LOOP-A is
transformer isolated to eliminate hum and
buzz caused by ground loops.
10. XLR I/O - Balanced line-level input and output
jacks for connection to profesional audio
devices.
11. ¼” TRS I/O - Balanced/unbalanced line-level
input and output phone jacks.
12. FULL BOTTOM PAD - Won’t scratch, keeps
the EXTC-SA in one place and provides
electrical isolation.

Radial Engineering Ltd. EXTC-SA
True to the Music
®
OVERVIEW
The Radial EXTC-SA is a professional audio interface that takes a +4dB balanced line-level
signal and converts it to a guitar-level effects loop and then re-converts it back to a +4dB
balanced line-level signal. In other words, you send in a balanced signal from your recorder,
adjust the loop send level that drives the pedals. Set the return level from the pedals as it
comes back and send the resulting signal to your recording system.
INPUT
+4dB
OUTPUT
+4dB
EXTC-SA
HIGH IMPEDANCE LOOP-B
SEND RETURN
PEDAL PEDAL
HIGH IMPEDANCE LOOP-A
SEND RETURN
PEDAL PEDAL
BLEND
PHASE
CANCELLATION
OUTPUT
+4dB
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE
INVERT
PHASE
NORMAL
PHASE NORMAL
PHASE
NORMAL
OUTPUT
+4dB
PHASE INVERTING PEDAL
PHASE INVERTING PEDAL
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE INVERT
PHASE
INVERT
PHASE
NORMAL
OK
DRY
DRY
DRY
Although simple in principle, the key to the EXTC-SA’s performance is how quietly it does
the task. This is achieved by employing full sized discrete electronic components, class-A
circuitry and transformer isolation to help eliminate the hum and buzz that is common with
pedals and guitars. The other cool ‘trick’ inside the EXTC-SA is the blend control. This mixes
the original dry signal with the newly introduced effects created by the pedals.
Something to think about here is how some effect pedals will reverse the polarity of the
signal passing through them. When you mix a dry signal with a wet signal and one is polarity
reversed, you will of course end up with cancellation. The diagram below illustrates a setup
where one pedal “B” is inverting the polarity creating cancellation where two out-of-phase
signals come together.
INPUT
+4dB
OUTPUT
+4dB
EXTC-SA
HIGH IMPEDANCE LOOP-B
SEND RETURN
PEDAL PEDAL
HIGH IMPEDANCE LOOP-A
SEND RETURN
PEDAL PEDAL
BLEND
PHASE
CANCELLATION
OUTPUT
+4dB
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE
INVERT
PHASE
NORMAL
PHASE NORMAL
PHASE
NORMAL
OUTPUT
+4dB
PHASE INVERTING PEDAL
PHASE INVERTING PEDAL
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE INVERT
PHASE
INVERT
PHASE
NORMAL
OK
DRY
DRY
DRY
The PHASE INVERT switch plays an important role by ensuring both the dry and wet signals
are in phase. The next diagram shows how the PHASE INVERT switch reverses the signal
polarity before it gets to the offending pedal. Pedal “B” gets tricked into re-inverting the signal
back to normal phase.
INPUT
+4dB
OUTPUT
+4dB
EXTC-SA
HIGH IMPEDANCE LOOP-B
SEND RETURN
PEDAL PEDAL
HIGH IMPEDANCE LOOP-A
SEND RETURN
PEDAL PEDAL
BLEND
PHASE
CANCELLATION
OUTPUT
+4dB
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE
INVERT
PHASE
NORMAL
PHASE NORMAL
PHASE
NORMAL
OUTPUT
+4dB
PHASE INVERTING PEDAL
PHASE INVERTING PEDAL
INPUT
+4dB
EXTC-SA
PEDAL
SEND RETURN BLEND
NORMAL
PHASE
PHASE INVERT
PHASE
INVERT
PHASE
NORMAL
OK
DRY
DRY
DRY
2

True to the Music
®
Radial Engineering Ltd. EXTC-SA
3
GETTING STARTED
Before making any connections, start by turning off your audio system and turning all
volume levels down. This helps protect equipment from turn-on transients that could damage
loudspeakers and other sensitive equipment. Connect the external power supply to the
EXTC-SA. There is no power switch. The EXTC-SA will power up as soon as you connect
the supply. An LED on the front panel will illuminate when power is connected.
Start by setting up the controls as follows:
1. Set the blend control to the wet position (fully-clockwise).
2. Make sure the PHASE INVERT is set to normal (switch outward).
3. Set the send and receive level controls at mid-way (12 o’clock).
Connections between the EXTC-SA and your pedals
are made via the unbalanced high impedance ¼”
LOOP-A & B jacks. Connections to the recording
system are made through the balanced XLR and ¼”
TRS inputs and outputs jacks.
Connect the +4dB output from your recorder to
the balanced INPUT on the rear panel. To send
the processed signal back, connect the balanced
EXTC-SA output back to your recording system
and route the signal to a new track. To connect your
pedals, simply patch from the high-Z ¼” SEND jack
to your pedal chain input. The output of the pedal
chain is returned to the EXTC-SA by connecting
to the RECV jack. We suggest you start with one
pedal patched into LOOP-A before connecting more
pedals to LOOP-B. This will make it easier to trouble
shoot when rst setting up the EXTC-SA.
Turn on the effect pedal and select LOOP-A by depressing the the front panel switch. An
LED will indicate LOOP-A is active. Press play on your recorder and send the track to the
EXTC-SA input. You should be able to monitor the return path in your recording system and
hear the effect. Separate SEND & RECEIVE controls make it easy to adjust the levels to
suit any effect device. Now, try varying the BLEND control by rotating it counter-clockwise
towards the dry setting to hear how the effect mixes with the original track. If you notice that
the signal is ‘thinning out’ when the BLEND control is around the 12 o’clock position the wet
and dry signals may be out-of-phase with each other. The ‘thinning out” is the result of phase
cancellation between the wet and dry signals. Try depressing the PHASE INVERT switch to
x the problem. If all is well, try adding more pedals and connecting LOOP-B.
Once you get the EXTC hooked up, you will nd it to be loads of fun! All of a sudden, you
will be going back into the attic looking for that box of forgotten pedals, dusting them off
and plugging them in. Some will sound fantastic, others will sound bad in a good way. Who
knows, only those brave enough to enter blindly into these cold waters may live to tell the
tale. One of the most common applications for the EXTC-SA is using it to add grit to a vocal
track. This can easily be done with a distortion or overdrive pedal. You will nd that the most
realistic effects are created by blending slight amounts of distortion with the dry signal. But
you can also have loads of fun creating Nine Inch Nails type tones and generally going crazy.
There are no rules, only guidelines.

Radial Engineering Ltd. EXTC-SA
True to the Music
®
4
RADIAL EXTC-SA SPECIFICATIONS
CONNECTOR WIRING
12
3
HOT (+)
GROUND
COLD (-)
XLR Connector
HOT (+)
COLD (-)
GROUND
TRS ¼” Phone Connector
HOT (+)
GROUND
TS ¼” Phone Connector
Circuit type: Class-A discrete, transformer coupled
Power requirement: Radial 15VDC/400mA power supply included
DRY WET
Frequency Response: 20Hz ~ 20kHz +/- 1.5dB 20Hz ~ 10kHz +/- 3.5dB
(-8dB @ 20kHz) Shaped for musical
instruments
Voltage Gain: 0dB 12dB - send & receive at max
6dB - send minimum, receive max
0dB - send & receive set at 12 o’clock
THD+N (1kHz): <0.005% @ 0dBu <0.002% @ 0dBu
Noise: -93dB -84dB
Intermodulation Distortion: <0.003% @ 0dBu input <0.02% @ 0dBu input
Maximum input: +11dBu +11dBu
Line Level I/O XLR & ¼` TRS INPUT XLR & ¼` TRS OUTPUT
Type: Rear Panel Input - Balanced XLR
Female & ¼` TRS
Rear Panel Output - Balanced XLR
Male & ¼` TRS
Impedance: 15k Ohms 200 Ohms
Headroom: -+25dBu
Effects Loop I/O SEND 1/4” output RECEIVE 1/4” input
Type: Unbalanced ¼” Unbalanced ¼”
Impedance: 1.5k Ohms 10K ohms
Gain (variable): From -14dB ~ +3dB
(0dB at center point)
From -99dB ~ +9dB
(0dB at center point)
Maximum Gain: +3dB +9dB
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.

True to the Music
®
Radial Engineering Ltd. EXTC-SA
5
RADIAL EXTC-SA BLOCK DIAGRAM
NORMAL
DIFFERENTIAL
AMPLIFIER
BAL/
UNBALANCED
XLR and
¼” TRS INPUTS
BAL/
UNBALANCED
XLR and
¼” TRS OUTPUTS
SEND
DRIVER
-14 to +3dB
GAIN
RETURN
DRIVER
-99 to +9dB
GAIN
BLEND
WET/DRY
CONTROL
BALANCED
LINE
DRIVER
BYPASS LOOP-A
LOOP-A
LOOP-B
POLARITY
BYPASS LOOP-B
ENGAGE ENGAGE
SEND RECEIVE
SEND RECEIVE
INVERT
X-FORMER
RADIAL EXTC-SA BLOCK DIAGRAM

www.radialeng.com
®
www.radialeng.com
True to the Music
THREE YEAR TRANSFERABLE LIMITED WARRANTY
RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in material and
workmanship and will remedy any such defects free of charge according to the terms of this warranty.
Radial will repair or replace (at its option) any defective component(s) of this product (excluding nish
and wear and tear on components under normal use) for a period of three (3) years from the original
date of purchase. In the event that a particular product is no longer available, Radial reserves the
right to replace the product with a similar product of equal or greater value. In the unlikely event that
a defect is uncovered, please call 604-942-1001 or email [email protected] to obtain an RA
number (Return Authorization number) before the 3 year warranty period expires. The product must be
returned prepaid in the original shipping container (or equivalent) to Radial or to an authorized Radial
repair center and you must assume the risk of loss or damage. A copy of the original invoice showing
date of purchase and the dealer name must accompany any request for work to be performed under
this limited and transferable warranty. This warranty shall not apply if the product has been damaged
due to abuse, misuse, misapplication, accident or as a result of service or modication by any other
than an authorized Radial repair center.
THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE HEREOF
AND DESCRIBED ABOVE. NO WARRANTIES WHETHER EXPRESSED OR IMPLIED, INCLUDING
BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR
A PARTICULAR PURPOSE SHALL EXTEND BEYOND THE RESPECTIVE WARRANTY PERIOD
DESCRIBED ABOVE OF THREE YEARS. RADIAL SHALL NOT BE RESPONSIBLE OR LIABLE
FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS ARISING FROM
THE USE OF THIS PRODUCT. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND
YOU MAY ALSO HAVE OTHER RIGHTS, WHICH MAY VARY DEPENDING ON WHERE YOU LIVE
AND WHERE THE PRODUCT WAS PURCHASED.
ProTools and Neve are registered trademarks of their respective owners.
Reamp, Reamper, Reamping are trademarks of Radial Engineering Ltd.
Copyright 2012 Radial Engineering Ltd. All rights reserved.
Specications and appearances subject to change without notice.
Radial®EXTC-SA™User Guide Rev1.1 August 2021 - Part #: R870 1222 00 Printed in Canada
Radial Engineering Ltd.
1845 Kingsway Ave., Port Coquitlam, BC V3C 1S9, Canada
tel: [phone] • fax: [phone] • email: [email protected]