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JX62™ Using & Applications

The following page is an overview that describes how to use the JX62. For complete details, we invite you to download the full manual by clicking on the icon at left.

Overview

The Radial JX62 is a guitar and amp switcher designed for live touring. It can be broken down into three basic building blocks:

  1. INSTRUMENT CHANNELS: There are six high-impedance input channels, each equipped with a ¼" input for the instrument or wireless system, a ¼" thru-put for connecting a dedicated stage amp or external direct box, a trim (level) control and a PFL (pre-fader listen) switch that routes the selected channel to the headphones. The channels may be used independently with their own amps or routed to the master A/B amp bus. Any or all channels may be active at one time. Channels-5 and 6 are equipped with dedicated direct boxes that allow acoustic instruments or bass guitar to connect directly to professional PA and recording systems.
  2. A/B OUTPUT SELECT: The output select section lets you control the A/B amps outputs. The front panel SEL switch is used to select the active amp while two LEDs display which output is active. You can also use the ON buttons to manually turn the A/B outputs on and off. At the rear panel, each A/B output features two ¼" outputs for guitar or bass amps plus parallel lo-Z balanced XLR outs for connecting to digital processors, PA and recording systems. All outputs are transformer isolated to prevent noise from ground loops and feature ground lift and 180° polarity reverse switches.
  3. MONITOR HEADPHONES: The monitor section works with the channel PFL switches and allows the stage technician to listen to, trouble shoot and tune instruments on or off-line. The monitor section consists of a MONITOR level control, ¼" headphone output (see warning on page 2), front and rear ¼" outputs for electronic tuners and powered monitors, and a bright LED indicator that illuminates when a channel PFL switch is depressed. When no PFL switches are used the headphones monitor the A/B amp bus.

Making Connections

The cool thing about the JX62 is that it can be configured in various ways, depending on your desired setup. However, we suggest starting with one instrument and one amp before adding additional instruments and electronics. This way troubleshooting is kept to a minimum. If you start by connecting everything at once it can be very hard to figure things out should you run into a problem.

First, connect a guitar or wireless system to the INST-1 INPUT. Next, connect your amp to OUTPUT-A. The amp outputs feature two parallel ¼" jacks for connecting one or two guitar or bass amplifiers.

Activate channel-1 by depressing its ON switch. The LED below the switch will illuminate indicating the channel is routed to the A/B amp bus. In the OUTPUT SELECT section, press the SEL switch to ensure output-A is active. One of the two LEDs below the SEL switch will illuminate to indicate the active output. Bring up the level on your guitar amp to a comfortable listening level.

Adding more guitars

A guitar plectrum makes a handy tool for using the TRIM and DRAG dials. Connecting amps: Each output has a pair of ¼" jacks for doubling up amps.Eliminating hum and buzz: Push the front GND LIFT switches in to eliminate hum and buzz at the ¼" amps outputs.Testing for phase: Turn on both amps and toggle the amp-B POL 180° switch. The ¼" THRU jack may be used to pass individual instrument signals on to additional devices like amps and tuners and direct boxes. To use the DRAG control on channels-1 and 2 push the recessed switch in and use the TRIM dial to set the amount of drag. The LED illuminates when DRAG CONTROL is active. The effect LOOP jacks are used to integrate. digital processor and effect pedalboards. Channel-5 and 6 DI outputs connect directly to the PA or recording consoles. Each A/B amp output bus includes a balanced XLR output with its own ground lift and polarity reverse. The PFL switch features a black cap than can be removed if not used. Channel-5 is shown with the cap removed. A bright LED under the MUTE switch. indicates the function is active. Use a small screwdriver to change setting. After connecting the JR2, push the recessed button to turn the remote on. MIDI integration using the ¼" JR2 remote interface.

After you have your first guitar and amp working, connect your second guitar (or wireless system) to the INST-2 INPUT. Use the channel ON buttons to turn off channel-1 and turn on channel-2. Note: as many channels as you like may be routed to the A/B amp bus at the same time by pressing the channel ON buttons. Continue connecting instruments to the remaining channels until done.

The TRIM controls let you reduce the input sensitivity on a particular channel. If you notice one instrument or wireless system is louder than another, you can reduce the TRIM to even the levels out between instruments. Start with all TRIM controls rotated fully clockwise.

Adding a second amp

Connect your second amp to OUTPUT-B. The two ¼" jacks are wired in parallel to make connecting more than one amp to output-B easy. Turn on your second amp and set it to a low listening level to test. Press the SEL switch to toggle the amp outputs. The LED indicator will change to amp-B.

A common problem when using two amps is hum and buzz. The A/B amp outputs are transformer isolated to help eliminate noise caused by ground loops. If however, you hear noise after connecting your second amp, try pushing in the amp-A and amp-B GND LIFT switches located on the front panel. This will float the signal grounds and further reduce noise. The switches are recessed to prevent accidental use. Use a small screwdriver to push the GND LIFT switch inward.

The next problem you may encounter when using two amps is phase cancellation that can cause the tone to seem 'thin' or 'distant' when both amps are on at the same time. Cancellation occurs when one amp is 'out of phase' and its speakers are moving in the opposite direction compared to the other amp.

To test for proper phase, turn on both amp outputs by pressing in the amp-A and amp-B ON buttons in the OUTPUT SELECT section. Set the amps to the same approximate loudness. Now try inverting the polarity by pushing in the POL 180° button on output-B only. Compare the instruments tone with the switch set to the outward position and then the inward position. Use the setting that sounds the fullest especially in the lower bass notes. If you can see the speaker cones of both amps you can visually confirm the speakers are moving in the same direction and thus in phase. Even if you are not planning on using the amps at the same time it's a good idea to set the amps in phase when sending signals to the PA or recording consoles.

The JX62 gives you two ways to control the amps. You can toggle between the two amps, one for rhythm and the other for soloing, using the front panel SEL switch or the optional JR2 footswitch. You can also bypass the A/B SE switch function and manually control the amps by depressing either the amp-A or B ON switches, located in the OUTPUT SELECT section. When either ON switch is depressed, its LED illuminates and the SEL switch is disabled.

Using the channel thru-put

Each input channel is equipped with a parallel ¼" THRU-put. This can be used to feed a dedicated guitar amp, tuner or direct box. For instance, you may be a multi-instrumentalist that occasionally plays an instrument that requires a special kind of amp. In this case, you could connect the THRU output to an amp dedicated to this instrument. Note: the THRU jack is a wired in parallel with the input jack and therefore will not be effected by the MUTE function.

Drag control

There are purists that do not like the sound of wireless systems and thus prefer to connect their guitars directly to their amps using a standard guitar cable. The primary reason is that they do not like the sound of the buffer and the load that is applied on the pickup.

The JX62 is equipped with Drag Control™ load correction that works with cabled guitars and passive magnetic pickups. Drag Control allows the player to adjust the load (impedance) applied to the pickup and smooths out the response for a more natural sound. After the DRAG circuit, the instrument signal is then buffered by a 100% discrete class-A circuit that will not color the tone before routing to the master A/B amp bus.

Drag Control is available on channels-1 and 2 by depressing the recessed DRAG switch. This converts the TRIM control into a Drag Control. Since most wireless or active instruments are often louder than passive electric guitar pickups, the trim is usually not needed. Use a guitar pick to set the DRAG control to 12 o'clock and then rotate to where it sounds best to you. Turning control counter-clockwise will apply more DRAG and darken the tone while turning it clockwise will brighten the sound.

Adding effects

The JX62 is equipped with an effects loop that lets you route all instruments to an effect processor or pedalboard. Simply connect the ¼" SEND jack to your effect pedals and back to the JX62 via the ¼" RECV jack. Connecting your effects here enables you to share them with all the input channels and both amps. Once connected the loop will be active and you can use your effects as normal.

Using direct box outputs

Channels-5 and 6 feature dedicated direct boxes equipped with lo-Z balanced XLR outputs, ground lift and polarity reverse controls. These mic level outputs can be used to send acoustic instruments like guitar, mandolin or bass direct to the PA or recording consoles. Use standard balanced XLR microphone cable to connect the direct box outputs to the mic/line inputs of a mixing console.

The direct box outputs are controlled using the front panel DIRECT OUT switches. The direct box ON switch works independently from the channel ON button. This way you can route the signal from an acoustic instrument to the direct box output only and not the electric guitar amp unless you want to. The direct box output is transformer isolated to reduces hum and buzz caused by ground loops. The GND LIFT switch adds a further level of noise reduction. If you hear noise after connecting the direct box output to the PA system try pushing the GND LIFT switch inward. This will disconnect pin-1 on the XLR output and further eliminate noise.

The direct box POL 180° polarity reverse switch can often help tame low frequency resonant feedback that can be a problem with acoustic instruments. When frequency waves from the PA, monitors, side fi lls and stage amp collide they can reinforce each other or cancel each other out, depending on where you are standing on stage and their relative phase and intensity. The polarity reverse switch essentially 'moves' the problem out of the way. Try the switch in both positions and use the setting that works best.

Using the A/B XLR outputs

As an added convenience, the JX62 is equipped with two balanced XLR outputs that are wired in parallel to the A/B amp outputs. These can be used to feed mic inputs on a mixing console when using the JX62 as a giant DI box. They can also be used to feed digital modeling amplifi ers or effect processors for those that prefer to perform in the digital domain.

Each XLR output is transformer isolated and features a ground lift switch to further reduce hum and buzz caused by ground loops. If you hear noise after connecting, push in the GND LIFT switch. A polarity reverse switch is also provided that inverts the signal phase 180 degrees.

Using the PFL system

Pre-fader-listen or PFL is a term used on mixing consoles to describe monitoring a signal that is not live. Each input channel features a PFL switch that lets you listen to the instrument signal via headphones or send the signal to a tuner or powered monitor speaker.

For instance, the artist on stage may be using channel-1 but you want to check the instrument on channel-2 to make sure everything is working and in tune before handing off the guitar. By depressing the channel-2 PFL switch you can listen to the instrument using the built-in headphone amplifi er or send the signal to an electronic tuner or backstage amp. When the instrument is set to go, the tech can hand it off to the artist and turn on the channel.

Each channel has a PFL switch with an LED indicator that illuminates when pushed in. An LED indicator in the MONITOR section also illuminates when the PFL system is active. When one or more of the PFL switches are on, the headphones and tuner outputs will monitor the PFL bus. When all of the PFL switches are off, the headphones and tuner outputs will automatically revert to monitoring the A/B amp bus.

Note: As some guitar techs will use the PFL and others may not feel the need, we chose to equip the function with black capped switches. These can be removed by gently pulling on the black cap using a set of needle nose pliers. This opens up more space on the front panel and reduces switching errors. After the tour, you simply replace the switch caps by pushing them back on.

Connecting a tuner and monitor speaker

The JX62 features two ¼" TUNER jacks that output a line level signal of the headphone mix. You can connect electronic tuners or other devices like guitar amps or monitor speakers using standard ¼" guitar cables.

The ¼" TUNER jack on the rear panel produces a fi xed level making it well suited for connecting electronic tuners because the output is always on and the level remains stable. The second ¼" TUNER out is located on the front panel. Here the level is controlled by the MONITOR knob. This ¼" output is good for connecting amps or monitor speakers because you can adjust the volume using the MONITOR level control.

Using the mute

The JX62 includes a mute function that makes it easy to change instruments or put the system in 'standby' mode. Pressing the front panel MUTE button turns off the A/B amps outputs but leaves the direct box outputs, headphones and tuner outputs on. Note: There is an option to also mute the direct box outputs described in the next section of this user guide. The LED indicator illuminates when the mute function is active. You can continue to use the PFL system via the headphone and tuner outputs while the MUTE function is on.

Note: the ¼" THRU jacks on each channel are wired in parallel with the input jacks and therefore will not be effected by the MUTE function.

Top panel controls for channels-5 and 6

Three 'set-and-forget' controls, located on the top panel, offer additional options for channels-5 and 6. The center switch labeled MUTE ASSIGN allows you to control how the JX62's mute function works with the channel-5 and 6 direct box outputs. When set to OFF the direct box outs are not effected by the mute function and will remain on while the amp outputs are muted. With this setting you can mute the amps (electric guitars) while playing an acoustic instrument through the PA system via the direct box outputs.

When the MUTE ASSIGN is set to ON, the direct box outputs will also be turned off (muted) along with the guitar amp outs. This setting lets you use the mute function to put the system in standby mode where the amps and acoustic instruments are off. The tech can still monitor input channels and tune the instruments using the PFL system.

The two switches labeled DI OUT SWITCH allow you to link the channel and direct box ON buttons. When set to OFF the channel and direct box ON buttons work independently. Used this way you can choose to send channels-5 and 6 to the direct box outputs but not the amp outputs.

When the DI OUT SWITCH is set to the ON position, the direct box outputs will turn on/off in sync with the channel ON buttons. Used this way, one button turns on/off both the channel and the direct box output. Choose a setting that works best with your set up. The top switches are recessed to prevent accidental use. Use a small screwdriver to change setting.

Using the JR2 remote control

For artists that prefer to control A/B amp switching for solos, an optional JR2 remote footswitch may be connected using a standard balanced cable up to 30 meters (100') long. The rear panel connection features an XLR jack and a ¼" TRS jack. The JR2 works with both cable types allowing you to use whatever cable you have at hand.

After connecting the JR2, push the recessed ON button located next to the XLR jack inward. This activates the JR2 remote connection and disables the front panel A/B SEL and MUTE switches. The A/B amp ON switches will still be available for manual control of the amp outputs.

The JR2 features two footswitches that duplicate the A/B SEL and MUTE controls. Depressing the A/B footswitch will toggle the JX62 A/B outputs allowing the artist to control the amps. The MUTE footswitch activates the JX62 mute function. Because the TUNER outs and headphones remain active the artist can quietly tune between songs or turn off the guitar outputs in between sets without the aide of a technician. The JR2 derives its power from the JX62 to perform the switching and illuminates its LED indicators.

Mini integration

You can use a MIDI controller or sequencer to trigger the A/B switching and mute functions by connecting a MIDI controlled contact closure to the JR2 interface. One contact closure is used for the A/B switching and another for the mute.

To access the JR2 interface, use the ¼" TRS jack on the rear panel and patch it to two MIDI contact closures using an 'insert' type cable. The following diagram shows the wiring for an insert cable that breaks out the ¼" TRS jack into individual plugs that can connect two MIDI contact closures.

An insert cable can be used to break out the switching and mute functions.