Tube Amps vs. Algorithms #1: History

"So, are you going to play accompaniment, or are you going to take solos as well?" That was the first crucial question in my musical career when I was a fifteen-year-old high school freshman auditioning for my first school band. "Of course I'm going to solo," I replied confidently, empowered by the fact that I had learned the first pentatonic progression in the twelfth position (i.e., where the two dots are) the week before.

But I realised right away that I was in trouble because in addition to the blunt short sound that is used for chords, I would now need the long, sharp sound typical for solos. But I'd already heard from my older friends that this could be achieved with a device they called a "booster", and I also knew that these boosters were made by my classmate's brother, who was studying electrical engineering at university.

Thus began my lifelong journey to the ideal guitar sound. I think that my story is similar to many other musicians of my generation and that they are all still more or less searching for their holy grail to this day. I don't know many (in fact, I'd say probably none) who found the ideal sound many years ago and haven't tried and bought anything new since.

The musical instrument industry, which profits from this inner drive of all musicians (not only guitarists), fosters this need for sound perfection through marketing. With every new product, they claim that it's just what you've been waiting for. Sometimes there's a grain of truth in that, sometimes not at all.

Regardless, I find the whole sound odyssey to be fun and exciting and I am grateful for it in a way. I've gone from my first booster made out of a plastic box to a device that not only gets mistaken for expensive tube machines in blind tests, but also has studio-quality effects, creates playlists, makes harmonies, and mimics a flute or Hammond. So progress has definitely been made.

Tube or Digital: the Fight of the Century

In the last few decades, the historical development of the electric guitar sound system has been greatly marked by a dilemma that has divided the guitar community perhaps even more than different political opinions. Tube or digital? This is the question that has split brothers, lovers, parents and children, and friends. I'm joking, of course, but to some extent it really is.

The implacable proponents of tube amps continue to trudge up the stairs with their ton of gear and despise the perverts with flashing pedalboards, carried casually in a shoulder bag. Digital fans, on the other hand, regard the former as fossils who haven't grasped that technology has advanced and that their modeller will mimic their pile of crap with one arm tied behind its back.

We should also mention that what we are addressing today is not just amplification of the sound, as was the case in the prehistoric days of electrified instruments. It is primarily about the resulting timbre and character of the sound, both in terms of frequency and dynamics. We've long been able to amplify the sound itself, but the question is what sound sensations we consider nice and pleasant and what feels good when playing.

So how to compare the two? Is there any impartial comparison that would prove what is actually better? Sure, there are "blind" tests where people compare sound samples without knowing how they were created. And that is where the differences have been wiped out. But I'm afraid there is no truly objective comparison and never will be.

Music is not a matter of meters, graphs on computer screens, oscilloscopes, frequency analysers, or other such things, but a matter of emotions. And you can't measure it. At least not with those meters. If someone believes in the magical power of their expensive boutique combo, that piece of wood and metal indeed has that power for them, and nothing can replace it. And if the owner of a Fractal, Cortex or Kemper is convinced that this is the right way to go, they won't bother ruining their back ever again.

But we can try to describe the current state of affairs, the path that led to it, talk a bit about technology and outline a possible future. Personally, I have both tube amps and modellers, so I consider myself unbiased and try to pick the best from both worlds. How about you?

The 70s: If it's supposed to play, it has to be big and heavy

Anyway, I'll go back to my teenage years, that is, the 1970s when I started noticing what gear my youth idols and my older friends had. I don't remember there being an alternative to tube heads and cabinets, or even heavier tube combos. Where did all this come from?

If we dig deep enough in history, we will probably get to the name of Lee de Forest. He was the man known as the "father of radio" who designed the first tube amplifier in 1906. But back then it wasn't for the guitar, it was for the radio. The need to amplify the guitar didn't emerge until the 1920s, thanks to the popularity of Hawaiian guitars and slide instruments in general. In fact, some manufacturers of these steel guitars wanted to supply the instrument with a device that could amplify it. Stromberg-Voisinet, Vega, Electro, Dobro, National and Rickenbacker were among the early pioneers.

In the 1940s, Leo Fender followed up with the Broadcaster/Telecaster, and later the Stratocaster and other inventions. And then a lot more manufacturers appeared. In the 50's Gibson went big, in the 60's it was Marshall and Vox. Anyway, I remember that if it was supposed to play loud, it had to be big and heavy. The distortion was done either directly in the amp or through some kind of a box. Personally, I was very impressed with the Boss overdrive, the first-ever professional distortion pedal. I wanted that one the most because the fuzzes used before that (which were also available in homemade versions, usually under the name "booster") sounded terrible.

The 80s: a time for transistor...

As time went on and rockers got older and their backs ached (I guess it was the beginning of the 80s in our country, in the world it was the mid-70s), the transistor combos appeared. They were small, portable, often fitted with effects and they played quite loud. Some of them became very popular. I remember the iconic British Session combos, the Sessionette 75, the Gallien-Krueger 250ML Stereo and the Peavey Bandit. The Roland Jazz Chorus, still in use today, has achieved legendary status.

It meant a major breakthrough and the end of the initial hegemony of tube amplifiers. Roland became a pioneer of solid state (i.e. transistor) and later modelling guitar amps in general, and remains so to this day. The Roland Blues Cube, Boss Katana and other products of this company are even among the world's best-selling electric guitar sound equipment ever, no matter how much they are looked down upon by Matchless, Two-Rock or even Rectifier and Diezel lovers.

... and for the first digital modellers' opening act

Transistors are not the only driving force behind the invasion of the previously untouchable realm of tube amplifiers. A far more insidious competitor emerged. In 1982, Tom Scholz, guitarist from the famous band Boston and a technical jack-of-all-trades, designed a box to wear on one's belt, which he named the Rockman. Inside this all-analogue device the size of the then-popular Walkman, he hid an imitation of his long violin tone that Boston fans admired so much. It became a kind of analogue foreshadowing of what was to come later.

Another analogue forerunner of digital modelling was New York guitarist and engineer Andrew Barta, who developed a pedal he called SansAmp and began selling it on behalf of Tech21 in 1989. This was a "serious modeller" in today's terms, containing simulations of famous amplifiers and even cabinets in a pedal form. It was still a fully analogue device using FET transistors.

The 90s: The Mock Digital Guitar Revolution

The real craze came a decade later, in the late 1980s, when the digital guitar revolution started. Marcus Ryle, who had worked for Oberheim and Alesis, and a guy named Michel Diodic (I can't think of a better last name in this business) started a company called Line 6. They designed the famous "red bean" which they named POD. It was the first commercially successful digital amp, cabinet and effects simulator.

It seemed that everything changed for the guitarists, forever. No one wanted to be left behind, so more and more digital modellers and multi-effects flooded the market. This put tremendous pressure on prices, causing manufacturers to scrimp on chips and other components, and Chinese factories started churning out one amazing digital unit after another.

Return to the tube amps

But once the initial euphoria surrounding digitalisation passed, the effect from the fairy tale The Emperor's New Clothes kicked in. Somehow, first quietly and then loudly, people started complaining that the sound imitations were not as perfect as the marketing claimed, that they sounded good only in certain positions, that guitars had a different response to a right-hand strike than guitarists were used to, that the effects did not have the promised studio quality, and so on. And the whole digital bubble burst as quickly as the dot.com craze. The old analogue pedals shot up in price to dizzying heights, and guitarists started going back to tried and tested tubes. No wonder. The cheap chips just weren't keeping up with the necessary computing power, and the companies dominating the market didn't want to invest in expensive technology because they thought such a product would remain sitting in warehouses as unsellable.

Fractal Audio Systems: if it's digital, it should be high-quality

But some manufacturers didn't get discouraged and decided that the digital systems could work, but that they had to be done properly and with higher costs. Players would have the usual choice: "This is the price. Take it or leave it." That is exactly how Cliff Chase founded Fractal Audio Systems in the US state of New Hampshire. The company came to market in 2006 with a pioneering rack-mount device called the Axe-Fx.

That was the real digital revolution, whereas the previous one was just a rehearsal. Here, the sounds really resembled their "live" models, the effects had a studio quality and soon this device appeared in the rack sets of all famous recording studios and in the boxes of top players.

Yes, the price did not compete at all with the colourful Asian boxes for all purposes. It was comparable to the price of an expensive tube amplifier. But the device could emulate not just one expensive tube amp, but a whole range of amps, cabinets and effects. Two years later, an improved Ultra model was out, and today there is the third generation of this unit on the market.

Kemper: digital imprint

Christoph Kemper from Germany approached it differently, even though he also knew that his product would not compete with cheap Asian chips. The way he sees it, the ideal device can instantly emulate the amplifier and cabinet favoured by guitar players. So in theory, the guitarist himself could, with the help of advanced algorithms, "capture and insert" their dream sound into their device and use it. He called this device a "profiler" and the process by which the amp is "imprinted" into digital form he called "profiling". Of course, his product, which first hit the market in 2011, already has a lot of profiles preset into it.

So what is the difference between a modeller and a profiler? Nothing dramatic. A modeller usually refers to a device that gradually models the sound of a selected amplifier or effect from scratch by adjusting individual parameters, whereas a profiler captures the desired sound without the need to set it up from scratch. Sometimes it is said that it "clones" it. Then it works with it further and thus the sound can be edited.

Line 6 and co.: While two dogs fight for a bone, a third one runs away with it

These two companies in particular, Fractal Audio Systems and Kemper Amps, started a game that represents a battle between the digital and traditional realms of the electric guitar sound. Line 6, a pioneer in the field, which by acquisition found itself in the portfolio of the Yamaha concern, did not want to be left out. So they came up with a product they named Helix, joining the two previously mentioned. We can call it a modeller and thus its direct competitor is mainly Fractal.

A relative newcomer to the field, albeit a very nimble one, is Neural DSP Technologies from Finland. Quad Cortex is the name of the flagship product that has been extremely successful in the battle for market share, thanks to its favourable price/performance ratio. It combines modeller and profiler technology using a so-called neural network, a learning system that learns the sound characteristics of a real amplifier from a number of samples. It is therefore primarily aimed at existing or potential Kemper customers.

In addition to these major innovators in the field, there are similar devices from other manufacturers – Headrush, Fender, the aforementioned Roland/Boss, Zoom and others. They all compete in more favourable price ranges with the modelling/profiling brontosauruses. The Asian competitors have also dramatically improved the quality of their products, although prices still remain below the market leaders. Yet the devices from companies such as Ampero, Nux, Valeton, Mooer and others are way more advanced in quality than the attempts from the 90s.

Guitar software: the heart of sound in a computer processor

Alongside the 'standalone units', i.e. the pieces of hardware used as studio racks, multi-effects or classic amps and combos, there's a vast area of guitar software that is used to emulate the sound of guitar amps and cabinets via the computer. So the heart of the machine is not a chip in a piece of metal, but a processor in a standard computer otherwise used in an office or home.

Even here, thanks to increasing computing power, the quality of simulations has reached the level where it is difficult to distinguish between the original and the imitation in "blind" tests. Fender's Amplitube or IK Multimedia's Tonex, Positive Grid's Bias, Native Instruments' Guitar Rig, Waves' GTR 3, to name a few, are all systems designed more for guitar recording than for live playing, although some of the inventions have crossed over from hardware to software and vice versa. Examples include the Neural DSP or IK Multimedia's Tonex. They exist in both hardware and digital form. This has started to blur the gap between "digital" and "hard material" and takes advantage of both, depending on the situation the guitarist is in and the task they are performing.

So we have quickly scanned the history to draw up a brief chronological sequence of technological developments. In the next part of this series, we will focus on the technical and physical aspects of the clash between tubes and algorithms.