The Legendary JD7



Typical JD7 stage setup with three amps connected -- the JD7 can combine and switch up to seven amplifiers with no noise or buzz. Two SGI TX and RX transmitter/receiver units are used here to drive cables up to 300 feet to a pedalboard and back with no signal loss



Managing a whack of guitars on stage is no mean feat...



U2's The Edge's effects rig is rack-mounted offstage, close to the amps.



Effects up close and under foot on a pedalboard.



Connect up to 6 amps to the JX44 back panel jacks.



The JR5 Remote's right and left XLR jacks adapt to any stage setup.



As a studio re-amper, the JX44 is second only to the world renowned Radial JD7.



Input 'D' on the JX44 is assigned exclusively to the DI output via back panel switch. The electric basses here can route to just the on-stage amps or both amps and DI.



The JX44's 'Panic' feature offers fast one-button relief.



The JX44 provides quick access to quiet tuning with an always-on buffered tuner output.



JX44 Air Control™ Development

The best ideas always come from the users. At Radial, we are blessed with a tremendous number of artists that use our product, many of which do so because of the urging of their stage tech's. The Radial JX44 Air Control is the culmination of ideas, suggestions and creative design from various guitar techs melding minds with our engineering team. This is the story that led to the JX44's development.

In the beginning - the JD7:

It all started in 2001, when we launched the Radial JD7 Injector. The JD7 is a guitar signal buffer and distribution amplifier that was originally intended as a creative tool for the recording studio. The JD7 lets you connect up to 7 guitar amps at once. It soon gained notoriety with bands such as AC/DC, Motorhead, Cheap Trick, Dream Theatre, John Mayer and Slayer and with guitar legends like Joe Perry, Steve Stevens, Steve Lukather, Carlos Santana and Buddy Guy.

On-stage requirements are often very different. Switching guitars and amps between songs must be quick and efficient. And 'who' makes the switching decision depends on the artist's preference, stage setup, and complexity of the performance. This meant looking at options such as how guitarists would use a switcher on stage and how the guitar technician would deal with various problems that could potentially arise during a performance. In more complex stage setups, we noticed that the guitar techs often added other components to the JD7 such as the Radial SGI (Studio Guitar Interface) to allow them to drive long cables to-and-from the pedalboard without noise. And while charting out the feature set, discussions included how one would best manage effects, simplifying programmability to reduce anxiety on stage and of course fail-safe measures to counter problems that may occur during a performance. In became clear... there was a need for a more advanced version of the JD7 that could address the fast paced demands of the live concert environment.

Enter the JX44... Selecting Guitars

Today, most 'concert level' guitarists use wireless systems so that they can freely move around the stage to enhance the performance. The guitar tech will attach a wireless transmitter to the strap which enables him to quickly exchange guitars with the artist between songs. While the artist is performing, the tech can tune the spare guitar and have others in the wings - ready at all times to substitute for a broken string, alternate tuning or enhance a creative moment. To reduce system set-up complexity, several guitar transmitters can share the same receiver. But even in this wireless world, the occasional need for an acoustic guitar or mandolin can also be called upon. And of course let us not forget the purist that refuses to downgrade his tone with any form of wireless voodoo!

After much deliberation, we felt that four guitar inputs would suffice. This would allow the tech to exchange guitars as needed and if more than four guitars were required, he could switch out body packs and cables These would be exclusive. In other words, when one is turned on, the other three would automatically be turned off. This would eliminate noise and allow the guitar tech to connect and disconnect guitars at will without interfering with the live performance.

One of the most important design elements was keeping the JX44 front panel clean and clear from cables that could get in the way and eliminate controls that could be switched my mistake. Showtime is no-time for guessing. We chose to locate most of the connections on the rear panel and added two connectors on the front with front-panel priority switching jacks to allow quick access for a guest artist or a panic situation. Because guitars output signals vary (active, passive, acoustic etc.) we decided to equip inputs A & B with Drag Control™ load correction for passive instruments while inputs C & D would be fitted with a trim control to tame active guitars and balance the signal between instruments.

The innovative Drag Control feature came from the Radial JD7. This allows the user to adjust the load on the pickup to replicate the effect of connecting to a tube guitar amp with a given length of cable. This is particularly important for the purist who expects the signal going to the amps to sound exactly as if connected direct.

Selecting the input also had to be flexible. The guitar tech will usually hit the select button on the JX44 front panel to choose the input. But when the artist is traveling 'light' he may want to have 4 guitars on stage put one down and pick another up. So we configured the JR5 remote footswitch to also work as a guitar selector by automatically changing function depending on which port is connected.

Routing the Effects

When it comes to effects, the options are unlimited. Some guys have 'fridge-sized' racks filled with drawer upon drawer of pedals and elaborate custom control systems. Others use multi-effects processors and studio outboard gear. Then there are the guys that prefer to use standard foot controlled effects pedals; they want them right at their feet on their custom wired pedalboards so that they can chose and combine effects on the fly to reflect the mood of the moment. The JX44 had to work in all environments.

What we did NOT want to do with the JX44 was to create a monster. We wanted it to be a single rack space device that would properly manage the tasks of guitar and amp switching and provide ultra-clean signal buffering. So we decided to make provisions for two different types of effects routing systems: one local and one remote. Local effects send and return are 'guitar level' and use standard ¼" jacks. This can be used to interface with any number of effects controllers or multi-effects processors that abound and the effects loop can be assigned to any one or all of the amplifiers. In fact, depending on how you program the JX44, the JR5 footswitch can be configured to remotely turn on the effects bus.

For pedalboards, another solution was needed. Most players know that when you extend a Hi-Z cable longer than 25 feet, noise has a nasty habit of getting into your system. Stages are filled with noise-causing devices such as power transformers, dimmers, digital controllers and LCD screens. The longer the cable, the more prone to noise the system will be. In large scale concerts, the guitar is typically equipped with a wireless transmitter that beams the signal to the receivers somewhere off stage. The signal then has to go from the transmitters, to the pedalboard at the front of the stage, through the pedals then back, under the stage, to the amps. If you were to measure the distance from the wireless to the pedals and back to the amps, you can easily total over 50 meters (150'). To address this problem, we decided to incorporate a special version of the Radial SGI - Studio Guitar Interface, called the SGI-44 into the JX44.

The Radial SGI is a proprietary balanced interface that can transmit the guitar signal via standard XLR cables to over 100 meters (300') without noise or tonal degradation. At the pedalboard, the second optional SGI-44 unbalances the signal for the effects pedals and then takes the output from the pedalboard and returns the signal to the JX44. For fun we even added a separately buffered tuner-out so that the artist can monitor his tuning on the fly.

Connecting Amplifiers

Ask any tone fanatic 'how many amps he would like on stage?' The answer is simple: A different one for every song! But how many amps do you really need? Maybe one amp for your clean tone, one for chunky rhythm and maybe another for soloing… and for fun, how about one more just because you can!

We settled on four amps with a total of six outputs. Outputs A and B are mono while outputs C and D are doubled-up to allow bands like AC/DC and Motorhead to have a wall of Marshall stacks on stage. With the JX44 'fully wired', you could connect a Twin for your clean tone on output-A. For your crunchy rhythm tone, you could set up a nice tube amp like a THD or Boogie on output-B and for soloing you could connect a pair of Marshall JCM800s using output-C and route your effects using output-D. To ensure any amp could be connected with any other amp without noise, all outputs are transformer isolated to eliminate ground loops and equipped with a 180º polarity reverse switch so that they could all play in phase.

Controlling Amplifiers

The next question had to do with controlling the amplifiers. Who turns them on and off during a show? Ask Santana's guitar tech Ed Adair and he will tell you that Carlos will select the amp and tone based on how he feels at a given moment. The decision is fluid. For other artists, the amp selection is choreographed precisely for each song and part of the guitar tech's nightly task is to ensure the right amp is on at the right time. The JX44 accommodates both camps.

In the simplest form, the Radial JX44 uses basic on-off footswitches for each amp so that the artist can turn on or off any amp at will. At the other extreme, the JX44 can provide programmability whereby various amp scenes can be preset and recalled at will. This is accomplished by incorporating a PIC ("Programmable Interrupt Controller") inside both the JX44 and JR5 remote pedal that send the control commands to the switch relays and retains the non-volatile memory to let you set up various scenes. Amp selection can be done by the tech using the front panel switches or by the guitarist via the JR5 remote footswitch. This way, you can be playing through amp-1 and by depressing footswitch-2, amp-1 can be turned off and amps 2, 3 and 4 can be turned on. Hit footswitch-1 and you can be back to amp-1. No tap dancing.

Because the JR5 footswitch would likely reside on a pedalboard like the Boneyard, we designed it with two standard 3-pin XLR connectors so that the remote cable could exit at either side of the pedalboard to adapt to more setups. Mic cables are easily found, easily repaired and can be extended to suit various stage sizes. This made sense as opposed to using some weird multipin connector. We also made it possible for the amp selector footswitch to remotely mute the system so that the guitarist could check his tuner at any time should a string be out.

Re-amplifying for post production:

Today, it is very common for bands to record their performances live and then go back into the studio to mix the various concerts in post production. A wonderful feature that we built into the Radial JD7 was the ability to re-amplify the signal in post production. We felt the JX44 should also be able to do the same. The process is simple: while you are recording your guitar track, take a 'dry' feed from the JX44's DI box output and record a clean track. After you are done recording, take the 'clean' track and send it back into the JX44 using the built-in X-Amp™ which can then drive several amps and pedals. Reamping has many advantages: First, if you are a guitarist, you can concentrate on your playing and worry about the recorded tone later. Second, if you make a mistake, it is easy to fix a clean note in ProTools and Reamp the track as needed. Best of all, you can use the JX44 to create new and exciting tone textures that have up until now been elusive.

The built-in direct box

This led us to think about how the JX44 would be used 'live'. What if the guitarist has an acoustic guitar? Where would this connect? Should the signal go to his guitar amplifier or go to a separate channel on the PA system? What if a bass player is using the JX44 and had to switch to an upright bass. How will he set his rig up? It became clear that the Radial JX44 had to be equipped with an assignable direct box. To accommodate acoustic instruments, input-4 could be able to be assigned to the direct box output. This way you could mute all the amps and have the acoustic go directly to the PA system. For Reamping, you could route all four inputs go to the DI out by hitting a switch. This way, the JX44 could be used for recording the show or specifically designated to a separate channel on the console for acoustic guitar or upright bass.

Managing disaster:

Truth is… wireless systems are prone to problems. These can occur due boundaries in the room, the abundance of interference from radio broadcast, CBs and taxies and the ever increasing use of airwaves for cell phones, blue tooth and wireless internet. But this is only one facet the guitar tech must prepare for… All electronic devices whether they are guitars, amps, effects and even ye virtuous Radial JX44 can fail. So what do you do when 20,000 screaming fans are out there waiting for the next screaming solo and the guitar stops working? In a word… panic. In fact, the difference between professionals and non-pros often comes down to preparation. Pros don't panic… they avert disaster by being prepared.

To solve the problem we introduced a panic button on the front panel. This 'hardwires' input-A to amp output-1 so that in the event a wireless system goes down, the guitar tech can quickly grab a guitar and a cable, run out to the artist and have him up and working in seconds. This provides the guitar tech with a simple yet effective 'get out of jail' card of sorts. And if for some reason the JX44 itself goes awry, even without power, the same 'default' setting will jump into place and automatically route the guitar signal to the amp. The show will go on.

On-stage tuning

Then we thought about tuning… What happens if the artist decides he wants to tune between songs? How does the tech manage the tuning? Who will mute the guitar? To address the multitude of possibilities, we incorporated a ton of options.

If the JX44 is being used by itself, you can connect the tuner to the rear panel and mute the JX44 using the mute switch on the front panel. Once depressed, all outputs will be muted except for the tuner and the SGI-44 send. For added convenience, you can connect a standard momentary switch (like a sustain pedal) the mute remote control jack on the rear panel and this will also mute the signal. This would accommodate a guitarist on a smaller stage. If you have a JR5 footswitch connected to the amps, you can mute the signal by depressing the center mute switch. This would of course allow the player to both control amps and mute. If the JR5 is connected to the 'Guitars' jack to control guitar switching, pressing the switch on a selected guitar will mute it.

To go one step further, the SGI-44 enables the player that wants to have a tuner at his pedalboard. The SGI-44 is equipped with a tuner out that lets you monitor tuning on the fly. When one of the three mute switches are depressed, the signal going to the amps and PA will mute leaving the on-board tuner out and SGI-44 tuner out unaffected.

Visual monitoring

During a show, when things are flying around break-neck speeds, the guitar tech needs to know exactly what is going on at all timers. To address this, we brought all of the main control status LEDs together into one zone called System Monitor. This allows the tech to scan the panel quickly to ensure the system is configured properly. There are even two LEDs that will flash every 8 seconds to let you know if the remote footswitches are happy.

To sum up, there has been a tremendous amount of thought put into the development of the JX44 and over two years of experimentation to get it right. But the wait was worthwhile. The Radial JX44 represents a true milestone in guitar signal management for the most demanding professional.