User guide

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1. INTRODUCTION
The Radial JX2 Switchbone was born from the demand we received from users
like you. The Switchbone is in fact a pared down version of the popular Radial JD7
Injector, a studio recording device that allows as many as 7 amplifiers to be driven
from one guitar.
The Switchbone has been optimized for stage use and allows a guitar to drive two
amplifiers and a tuner from one guitar input and do it without introducing buzz, hum,
or distortion.
Sounds easy enough… but it is not. For those that have tried connecting two
amplifiers together using Y-cords or some of the other AB-Y boxes that have come
before, you are familiar with the many challenges: Drop in gain, tone changes,
buzz and hum just to name a few. The Radial Switchbone is a remarkable device
that deals with all of these problems and brings forth a design that is easy to use,
musical and truly effective.
Please take the time to read this manual before you plug in. It will help you get the
most out of your Radial Switchbone and also eliminate potential shock hazards that
can occur when connecting equipment together.
2. CONCEPT
The Radial Switchbone begins with the concept that most ‘tone crazy’
players will generally use two amps on stage. (Of course more is better,
but then someone would have to carry all those amps to the gigs!)
When one drives two amplifiers with one guitar, the signal from the pickup
is divided in two and the sound changes. To get around this problem,
the Switchbone employs a unique Class-A amplifier circuit that has been
optimized for use with guitars. With customers like Eric Johnson, Carlos
Santana and Neal Schon, we are not allowed to alter the sound of their
favorite vintage axe. The sound must be real!
This leads to the next problem: Your guitar has now gone from being pas-
sive to essentially becoming active. Your pickup is no longer connected
directly to the amplifier. It is being ‘buffered’ (amplified). The natural relation-
ship is lost. To compensate for this, we have introduced a feature called
Drag™ control to allow you to reintroduce the natural loading that is lost.
With load-correction, the instrument goes back to normal. It breathes!
Finally as soon as you connect two amplifiers together they hum, they
buzz and sometimes even spark with hundreds of volts! This is due to
the way that each manufacturer builds their amplifiers. Some use positive
ground, others negative. Some use the chassis as a ground plane and
some old designs from the 50’s and 60’s that do not have proper 3-pin
safety U grounds. The Radial Switchbone incorporates a transformer iso-
lated output, a ground lift switch and a polarity reverse switch to allow your
two amplifiers to be used in tandem. These are designed to separate and
isolate the electrical current of each amplifier and eliminate ground loops.
Radial Engineering Switchbone Owner’s Manual
True to the Music True to the Music