DXJ112 Digital Guitar Amplifier

Appendix A

Designer’s Note: Amplifier Modeling:

Building an amplifier model is really not much different than building an actual amplifier. With an actual amplifier you start with components like tubes, transformers, resistors, capacitors, and a speaker, and put them together to create an amplifier. With a virtual amplifier you start with virtual components and put them together to create an amplifier model.

It all starts with what many consider to be the "magic" in the sound of many vintage amplifiers: the vacuum tube. We created a tube model flexible enough to emulate different types of vacuum tubes, from preamp tubes such as the 12AX7 to power amp tubes like the 6L6 and the EL84.

Next, we constructed models to duplicate the filtering and equalization that takes place between the gain stages of an amplifier. These equalization models are adaptable to precisely emulate the frequency characteristics of a specific amplifier’s controls. We even created models for the output transformer and power supply sag characteristics.

After extensive research, we discovered that there's really no magic in the tube itself. Much of the tube amplifier sound is a result of not just the tube, but the way the tube interacts with the other components in the amplifier. We created our tube models to interact with the other components in our virtual amplifiers, just like the real thing.

After we developed our component models, we put them together to create our virtual amplifiers. We sound tested our amplifier models extensively to ensure that they remained true to the sound and feel of the original amplifier. Although we may have taken the magic out of the tube, we wanted to keep the magic of the tube sound.

The diagrams on the following page show the signal chain of the DXJ112 amplifier.

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Crate Amplifiers DXJ112 manual Appendix a, Designer’s Note Amplifier Modeling
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DXJ112 specifications

The Crate Amplifiers DXJ112 is a powerful and versatile guitar amplifier designed to meet the needs of both amateur and professional musicians. This model stands out in the competitive amplifier market thanks to its rich feature set, advanced technology, and robust construction.

At the heart of the DXJ112 is its 12-inch speaker, delivering a dynamic range and clear sound that can handle everything from crisp clean tones to heavy distortion. With a power output of 75 watts, the amplifier can easily fill a rehearsal space or small venue, making it an excellent choice for live performances. It also includes a built-in digital effects processor with multiple effects such as reverb, delay, chorus, and flanger, enabling musicians to enrich their sound palette without the need for external pedals.

The DXJ112 incorporates an innovative preamp design that enhances tonal versatility. This amplifier features multiple channels, including dedicated clean and overdrive channels, allowing players to switch between pristine tones and aggressive distortion seamlessly. Each channel is equipped with individual EQ controls, enabling musicians to customize their sound to perfection.

One of the standout technologies in the DXJ112 is its intuitive user interface. The layout is designed for ease of use, ensuring that players can quickly adjust settings during practice or performances. Additionally, the presence of an auxiliary input means musicians can easily connect external devices such as smartphones or tablets, allowing for effortless jamming along with backing tracks or favorite songs.

Portability is another key characteristic of the DXJ112. Its lightweight design and sturdy carrying handle make it easy to transport, while the durable cabinet ensures that it can withstand the rigors of being on the road. The amp also includes a headphone output, perfect for silent practice without disturbing others.

Overall, the Crate Amplifiers DXJ112 is a fantastic choice for musicians seeking an affordable yet powerful amplifier. Its blend of solid construction, advanced features, and versatile sound options make it suitable for various styles, ensuring it remains a reliable tool for any guitarist's arsenal. Whether for live performances, studio work, or practice, the DXJ112 proves to be a dependable and inspiring instrument.
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