Digital Modeling Comes of Age

The Harmony Central Buyer's Guide To Digital Modeling Amps (Part One)

by Emile Menasché
June 28, 2000

Just a few years ago, the subject of digital amps would have generated as much interest at a guitar convention as pâté at a Hell's Angels pig roast. Digital guitar preamps existed; some even flourished. But the most successful models kept the core part of the tone -- the distortion -- in the analog domain. Digital distortion? Well, that was the reason God invented the bypass button.

Digital modeling changed all that by offering tube-type tone in responsive, flexible, and cost-effective packages that retained much of the flavor of the amps and effects guitarists have known and loved forever. Suddenly, it was safe for guitarists to go digital. A modeling amp's mission is to stuff all the sounds associated with a wide variety of traditional amps into a single box. After all, few of us have the budget -- let alone the back muscles -- to support a complete amp arsenal. Most of us are restricted to using one or two functioning amps at any given time. Instead of having to make choices about whether to buy a distinct brand of tube amp -- a unit with an inherent tonal character -- you can opt for a digital unit designed to replicate the tone of many of the most popular amps of the last 45 years.

The range of guitar tools that use some form of modeling is growing to include amps, preamps, effects, software, and combinations of the above. And as the technology matures and becomes more established, some patterns have emerged, including a trend toward simpler devices and a definite bias toward vintage-type sounds. Interestingly, though most modeling amps take their sonic inspiration from the same hit parade of vintage amps, the execution can vary widely from brand to brand, and even among units by the same builders. Some devices concentrate on the basics -- the sound of a tube amp and some effects -- while others delve into every aspect of the guitar sound: the wood, the pickups, their position, the amp, the speaker cabinet, the microphones used to record the original analog amps, and more.

Even if all features are equal, it's interesting to note that a digital model, the product of supposedly cold technology, is still open to the interpretation of the human ears designing it. That's a fancy way of saying that two digital amps designed to model the same vintage circuit can sound and feel quite different from one another.

In Part One of our modeling series, we'll look at how modeling technology stacks up against traditional tone tools and see how its strengths and weaknesses might apply to your music. Next time, we'll get into the way a modeling amp operates, and offer some shopping and testing tips.

Sonic Preview

Click the links below for a quick listen to some Johnson J-Station models.

Black Face: based on a vintage Fender (MP3, 131k)

Brit Stack: based on a Marshall stack (MP3, 173k)

Rectified: based on a Mesa Dual Rectifier (MP3, 166k)

Flat Top: designed to make an electric guitar sound like a dreadnought acoustic (MP3, 146k)

Match the Tool to the Task

A true digital model is designed to emulate the characteristics and performance of a physical object. In the case of guitar amp, a model is not intended merely to sound like a specific amp; it's meant to behave as that amp would in real life.

A real tube amp is an interactive device; its performance changes depending on conditions, and each component influences the performance of the others. Turn up the volume on a vintage tube amp -- especially a low-watter -- and you'll hear more than the loudness change. Distortion will creep into the circuit; the guitar will become more compressed; the tone may take a new shape, too, with highs and upper midrange becoming smoother. These characteristics aren't fixed: A subtle change in your guitar's volume (or in the voltage feeding the tubes) can alter the sound significantly. The player is rewarded for his or her actions. This is the heart of the magical response that has kept the tube amp viable in a solid-state world. A digital modeling amp sets out to recreate that experience, to offer the same rewards as a good tube amp.

How successfully the technology achieves this goal is largely a matter of perspective and taste. If you're in the room with the real thing, few experiences match the visceral thrill of playing through a hefty tube stack at full volume. You don't merely hear the amp: you feel it. That kick in the pants is from sound waves reaching across the room, drawing you into the tone as an active participant. I have yet to hear a digital circuit that can give me the same feeling. But for many players, owning a monster stack is like driving a Ferrari in rush hour traffic: you may get to open it up once in a while, but most of the time it sits there, taunting you.

Yamaha DG-1000

Next Page: The Case for Modeling

Emile Menasché is the Senior Editor, Guitar/Bass at Harmony Central. He previously served as Editor-In-Chief for Guitar Shop magazine.