Using the JDX is ‘plug and play’ easy! We recommend that you employ two high quality 12-guage speaker cables to ensure the best signal transfer. Connect the output from your head to the JDX FROM AMP and the TO SPEAKER to your cabinet. Then connect the XLR output to the mixing console.

It is important to note that the higher the quality of the preamp or console, the better the sound. This may seem obvious to some, but after exhaustive listening tests, we found that a high quality transformer-coupled preamp definitely produced superior results! Alas, these also cost more.

Once your cables have been connected, power up the JDX using the 15VDC power supply. A front panel LED will illuminate to tell you power is present. You are now ready to turn on your amplifier and the audio system. Always test your signal path at low levels to make sure connections have been properly done.

You are now set to play. If you are using wedge monitors on stage, try moving around and reversing the polarity to hear how your guitar sound from your amp and the monitors interact. If you encounter hum or buzz, try lifting the ground switch.

Combining the JDX with a microphone

To add greater depth and ‘fat’ to your guitar tone, try combining the sound of the JDX with a microphone. The two signals can be mixed together to create rich textures. Try moving the microphone around the room to find the sweet spot where the fundamental frequencies or harmonics line up to create a satisfying tone.

Another studio trick involves sliding the direct (JDX) track using a digital recording system. By delaying the direct track, you are essentially performing the same function as using the Radial Phazer (described below) and aligning the fundamental frequencies to create a fatter tone.

Using the JDX with a Radial Phazer™ 360º phase allignment tool

Combining the sound of a microphone with the JDX can be very rewarding. But to really go all the way, you have to consider the problem you have created by combining both sounds: The signal coming from the amp through the JDX is traveling at the speed of light (via electron flow), while the corresponding sound arriving at the mic capsule via the speaker is travelling at the speed of sound. Thus, the speaker/mic signal arrives later than the direct JDX signal due to the time it takes it to travel through the air. This difference in phase allignment causes cancellation at various frequencies commonly known as 'comb filtering'.

You have to now ‘correct’ the situation by aligning the two signals 'in time' so that their fundamental frequencies are in phase. This sounds complicated but the good news is that you need only use your ears to make it work—it’s that easy!

To make this all work, you will of course need to use two channels on your mixer: one for the mic’ed signal and the other for the direct feed from the JDX.

The Radial Phazer™ is a line level, analogue phase controller that allows you to adjust the direct feed from the JDX so that it is in phase (in time) with the mic’ed signal. Connect the Phazer to your mixing console using the insert point on the JDX's channel strip. This can be done with balanced or unbalanced cables or using a typical insert cable with TRS at one end, and two 1/4'” plugs at the other. (See the Phazer’s owner’s manual for more details)

Once connected, simply turn the phase adjustment knob clockwise - slowly - starting from the left until you find the sweet spot. This will be when the two sounds combine to create a fat rich bottom end.