Q: Can I use all the JD7 outputs to my amps at the same time?
A: Yes. The JD7 is a high-impedance, unity gain distribution amplifier. This means that it takes the original signal and then amplifies it at so that each output to the amplifiers is the same as the original input device.

Q: Whenever I have tried to connect more than one amp together in the past, I have experienced all kinds of hum and noise. How does the JD7 get around this problem?
A: The problem you were experiencing in the past was caused by what is commonly known as a ground loop. Each amplifier is different and as such, has different chassis voltages referenced to ground. When you connect these together these voltages combine to cause noise and hum. The Radial JD7 is equipped with isolation transformers on most of the outputs. These electrically isolate the amplifiers from each other thus solving the ground loop problem.

Q: I have tried many A+B boxes but they always change the sound of my guitar. Why?
A: If you simply Y-jack the output of your guitar, the signal going to each amp is cut in half or to be more precise, you will experience a 3dB loss at the input. You loose punch, dynamics and drive which makes your guitar sound lifeless and thin. Most A+B boxes are simple passive devices that cause this problem. The next level AB box uses inexpensive drive circuits (opamps and IC’s) to step-up the power so that you do not experience the power loss. These circuits are cheap to build and unfortunately sound like it. They are brittle and unnatural and ruin the sound of the guitar.

Q: Will the JD7 change the sound of my guitar?
A: The JD7 is as perfect as perfect can be! The JD7 has been designed to reproduce your guitar as faithfully as technology will allow. In other words, although nothing is perfect, the JD7 is as close to perfect as possible. The JD7 does not employ any opamps or ICs – it is 100% discreet Class-A. This is what audiophiles insist on for best reproduction. Further, the JD7 uses the worlds finest Jensen Transformers. The best circuit with the best components produces the best results.

Q: Can you explain Drag control?
A: After we built the 1st JD7 prototype, we knew it was exceptionally accurate. It was perfect. In fact it was too perfect. The problem was that it did not sound right. After many hours of testing, we found that there was a relationship between the guitar and the amplifier that was being lost. When a guitar is connected to an amplifier, the amplifier’s input section, tubes and transformers combine to create a load on the pick-up. This ‘loading effect’ combined with the type and length of cable further causes a noticeable tonal change, especially on lower output single coil or vintage humbucking pick-ups. Although subtle, the change was more than tonal; it had to do with the feel and grind of the guitar. This was the problem: When the guitar was connected through the JD7, the natural loading and resistance was lost. The guitar no longer saw the amplifier; it was seeing the perfect input on the JD7 while the amp was seeing the JD7’s perfect output. The relationship was lost. The amp was no longer ‘dragging’ down the pick-up. Drag control recreates this effect by allowing the musician to adjust with the guitar’s impedance and resistance before it is sent out to the amplifiers. Drag is subtle yet absolutely awesome!

Q: So why not simply buy an active direct box?
A: Active DI's can be good but they can have several disadvantages: First and foremost, active direct boxes require power. This means that they must either run off batteries, phantom power from the console or use a power source like a 'wall-wart' or AC/DC supply. When the power is low, they distort. This means that for the direct box to work well, you must keep the batteries at full charge which is impractical if not impossible.

Q: Does Drag control work on all pick-ups?
A: No. Not really. It is designed for passive pickups and it has virtually no effect on active devices or keyboards.

Q: Can I use a foot switch to control the JD7 so that it can be used live?
A: No. The JD7 was not intended for live use as few if any guitarists (except at the very high end) that would ever use more than two amps on stage at any time. This being said, there are some professionals that employ JD7s on stage in conjunction with custom effect board switchers. To address this need, we offer an ABY foot pedal in our Tonebone series called the Radial JX2 Switchbone that is a pared down version of the JD7 for live use. It allows one guitar to drive 2 amplifiers.

Q: Can I control the level going to each amplifier independently?
A: Not from the front panel. The problem is that when you change the level going to the guitar amplifier, you are in fact changing the tone and saturation at the amp’s input. For minute adjustments in the control room, one would normally increase the volume on the mixer for the given microphone on the target amplifier.

Q: I notice that there are two effect outputs on the JD7. Can these be used as extra outputs?
A: Yes. Maybe we should have called the JD7 the JD10… The effect loop outputs on channels 5 and 6 are always engaged. Depressing the loop switch on the channel front panel turns the ‘receive’ on. This means that you can use these outputs for other devices. Keep in mind however that these are not transformer isolated outputs and will be subject to ground loops if one is not careful.

Q: Can I use any amp with the JD7?
A: Yes or course. However please keep in mind that in order to keep noise down and to avoid getting a shock, you should always use properly designed equipment with 3 prong plugs. The 3rd ground plug is there for safety and using older 2-pronged amplifiers can be both dangerous and noisy. Always connect channel-1 to a relatively new amplifier with proper grounding. This is where the JD7 derives its ground. You must make sure that any old amplifiers be set to the correct electrical polarity. Read the owner’s manual on this matter as this will not only protect you from electrical shocks, but it will also reduce noise.

Q: Can I use effect pedals with the JD7?
A: Absolutely! You can use any guitar level device at any input or output as all of these are guitar levels. You can even use higher level instruments on input B by depressing the PAD.

Q: Is the balanced out on the JD7 line level?
A: No. It is mic level. The output is about the same as what you would get from a direct box. This allows the JD7 to be used in a concert or recording splitter snake system. The JD7 balanced output should be connected to a mic preamp or mixer mic input.

Q: What is Class-A?
A: This is the preferred amplifier design for circuits where sound quality is more important than high-power. In fact, audiophiles love the way Class-A circuits sound, as they do not introduce anomalies such as zero-cross distortion which of course cause phase distortion and inter-modulation distortion.

Q: Why does the JD7 have polarity reverse switches?
A: Many amplifier and effect pedal manufacturers assume that you will only be using their product and as such, they may end up being ‘out of phase’ or to be more precise, be polarity reversed from one and other. This of course only matters when you play several of these together at the same time. As this is the intended function of the JD7, the polarity reverse allows you to ‘line-up’ all of the amplifiers and pedals so that you get them all working together.

Q: How do you activate the XLR remix input?
A: The A-B selector will allow you to select between A or B or if B is not used (1/4” not connected), the rear XLR jack becomes active when input B selector is depressed. This is a line level input with variable trim to prevent high output levels from recorders from overloading the JD7 input circuit.

Radial - True to the Music™