A: This is both true and untrue. In the perfect
world, a guitar pickup should be connected directly
to the amplifier with no pedals in between. But
when a pedal like the Loopbone is inserted, this
device needs to perform various functions such as
dividing the signal to various signal paths we call
effects loops. If we did not buffer the circuit,
the guitar pickup would have to drive more than
one effect loop at a time and this would cause the
power going to each effect loop to be cut in half.
Turn your guitar down when driving a distorted signal
and you will immediately notice less sustain and
less overdrive. This necessitates the use of buffers
in the signal path. We developed a very clean Class-A
circuit and introduced Drag Control to counter any
effect that the circuit may have on the guitar.
The results is a cleaner, more natural tone with
all of the subtleties and dynamics that folks have
come to expect when they purchase a Radial product.
explain Drag™ control?
A: When a guitar is connected directly to
an amplifier, the guitar pickup and the amplifier
form a circuit. It is the relationship between the
amp and the way that it loads down the pickup that
creates its distinct sound. In buffered circuits,
we introduce a pre-amplifier in between the pickup
and the amp and this eliminates the load on the
pickup. Drag control allows the guitarist to reintroduce
a corrective load into the signal path and bring
back the natural relationship that would otherwise
Q: What is 'true bypass'?
A: The term 'true bypass' comes from problems
associated with some pedals that even when off,
have the effect of loading down the pickup. This
means that instead of 100% of the signal bypassing
the effect pedal, some of it is absorbed into the
pedal even when it is not being used. The perfect
‘true bypass’ switch would be one that
completely disconnects the pedals PC board and circuit
from the signal path. Unfortunately, this type of
mechanical switching causes pops in the audio path
when switched in and out.
Q: Why do some manufacturers
claim relays are the best way to switch effects?
A: Relays are a good solution as
they are, in fact, remotely controlled mechanical
switches. The problem with a mechanical switch,
however, is the transient switch noise caused
by the contacts arcing as they approach each other.
We use relays in several Radial products, but
relegate these to applications where the signal
will not be an amplified one. For devices that
pass audio before a guitar amplifier, we prefer
to use opto-couplers. These devices can be used
to perform various functions and in this case,
we use them like a switch with a programmed ramp-up
and ramp-down time. This means that the signal
does not ‘click’ on but actually rises
to an ‘on’ status, eliminating the
transient that causes a click or pop. Some older
amps switched channels using opto-couplers (also
known as photocells), but today most amps use
other electronic switching methods due to the
higher cost of opto-couplers and supporting circuitry.
Q: Can you explain
what a Class-A circuit is?
A: A Class-A circuit is the purest form
of amplifier design. Class-A employs a single
amplifying device, such as a tube or transistor,
to create a gain increase by amplifying both the
positive and negative portions of the audio signal
together. Class-B or Class-AB amplifiers employ
two separate gain stages whereby one amplifies
the positive side of the wave and the other, the
negative side. The two halves are then rectified
(brought back together) to create the final output
stage. Class-B and AB amplifiers are much more
efficient from the standpoint of power consumption,
weight and cost but have the trade-off of being
less natural sounding. This is caused by the impossible
problem of bringing the two separate waveforms
back together in perfect synchronization. The
effect is known as zero-cross distortion, to signify
the zero point where the plus waves and minus
waves must meet. Zero-cross inaccuracies cause
other artifacts such as phase distortion, harmonic
and intermodulation distortion.
Amps using Class-A circuits on the other hand
are larger, heavier and less efficient, consuming
much more power and adding noise, if not properly
designed. This puts added pressure on the circuit
designer to come up with a solution that works.
Hi-impedance guitars with those single coil, noise-attracting
pickups are arguably the most demanding of all.
This means that you need to have real talent and
tons of experience to develop a Class-A circuit
that sounds right and performs without noise.
This is where Radial's design team excels and
is well ahead of the pack. That's why our products
are so well liked by professionals that can discern
Q: Can the Loopbone
be used as an AB-Y for my amp?
A: No, not really. To properly and safely
perform AB-Y switching, one should have isolated
outputs such as found on the Radial Switchbone
and the Radial JD7. Keep in mind that amplifiers
can often be floating several hundred volts around
their circuitry and if not connected properly,
can lead to an electric shock. The Loopbone’s
output, in theory, could be connected to two amplifiers
in order to perform switching, however, we would
recommend that you have a qualified technician
on hand to ensure that the amps are properly grounded
and the connection is safe.
Q: Can I use the tuner out to drive an amplifier
or another effect device?
A: No, not really. Once again, you should
have an isolated output if you intend to drive
more than one amp at a time. Also, the tuner output
is on all the time and is unlikely to provide
you with any benefit that could not be realized
using the Loopbone the way it was designed to
I drive long cables from the Loopbone to my amp?
A: Yes. The Loopbone incorporates a low-impedance
Class-A buffering circuit, therefore you can drive
much longer cable runs with less noise than if
you are connected directly from the guitar to
the amp. We recommend a maximum distance of 50
Q: Will Slingshot™
remote switching work on all amplifiers?
A: Yes and no. Most traditional style amplifiers
will work with the Slingshot but there are surely
some amp designs that do not follow convention.
If you are not sure, consult your Tonebone dealer
or have a technician look at your amp to see if
it can be adapted to be compatible.
Q: How do I know if my amp will be Slingshot™
A: If your amp employs a basic footswitch
with a ¼” jack, it will in all likelihood
be compatible. If it employs some type of multi-pin
connector or telephone style jack, it probably
will not work without a custom adaptor.
Q: Is there a way to set the Loopbone up so that
it can mute for tuning?
A: Yes. All you do is insert a simple on-off
footswitch in one of the loops – then when
you want to tune, hit the switch before you activate
the loop. This will eliminate any contact switch
noise from the mechanical switch. When the song
stops, hit the loop and your signal will be muted.
Q: Does the boost control
boost everthing that comes out of it?
A: Yes! The power booster in the Loopbone
will boost the guitar signal straight out and
the signal passing through both loops.
Q: Can the Loopbone be used
in the serial/parallel FX-Send-Return of an Amp?
A: Yes - so long as you are running this
at instrument levels. Please
check with the amp manual or manufacturer. If
it says you can use guitar effects - you are good
Q: Will the loopbone work
A: Yes! The Loopbone will work well on
Q: When using the Loopbone
is the connection to the
loops in series or parallel. I would like to use
a volume control to create effect swells?
A: When you engage a loop on the Loopbone,
it takes the guitar
signal and diverts 100% of the signal through
the effects device. On the
other hand, the BigShot MIX lets you mix in two
effects and would be better suited as it would
allow the dry guitar signal to pass through and
you could bring in as much of the effect as you
would like using the volume pedal.
Q: Are there any manufacturers that make multi-power supply bricks for Tonebones?
A: Yes; The Cioks DC10 and AC10 both have 15V outlets for Tonebone pedals.
Q: Is it possible to use one of the loops as a DI send?
A: Yes. You would simply connect a DI like the Radial ProDI or J48 to the one
of the loops. This would enable you to 'turn on' a signal to the PA system
whenever that loop is selected. Make sure you connect the Loopbone Send to
the DI input and the thru back to the Loopbone if you still want the signal
to go to your on-stage amp. If you do not want to hear the on-stage amp,
then do not connect the thru cable. This will cut the signal path off so
that it only will be heard going to the DI and PA system.