Snake Oil! (part 4, tubes/valves)
Is there anything, in the world of musical equipment, more hyped than tubes? Every catalog and every gear website is laden with chatter about the warmth, fatness, and “vintage tone” you’ll get from their tube pedals, preamps, amps, rack processors, and gadgets of every type. The ads for some effects boxes say they’ll give you all the rich, creamy tones of a classic tube amp, even if there’s just one tube stuck in there with no clear function. And sellers of tubes will go on at length about the amazing tone, clarity, frequency range, smoothness, and “depth of sound stage” that their special tubes will provide.
It’s not all lies, exactly, but there is an awful lot of empty and meaningless hot air in there. Here’s why:
The classic/vintage designs of tube equipment include preamp tubes, an output transformer, large filter capacitors, and (in the case of a tube amp) a bank of power tubes—and all of those elements have a cumulative impact on the sound. Additionally they are designed so their tubes are supplied with ideal amounts of voltage and current for optimal performance.
Compare all that against a typical preamp or pedal marketed as having “a real tube” for warmth and fat vintage tone: it will have one or maybe two preamp tubes, but none of the rest of those other components and qualities. Often the voltage and current are just barely enough to operate the tube, with no regard for whether the performance of the tube is even any good, let alone having the tone qualities they advertised. Sometimes the tube has no perceptible effect on the sound; sometimes all it does is add noise; and sometimes the “vintage” tone it gives is just a mushy, inarticulate degradation of the signal. Among people who understand the difference, these products are called “toob” effects/amps, to mock the bogus use of a tube for marketing purposes.
To be clear, not all preamp-tube devices are bogus. A skillful engineer, using design principles for optimal performance rather than convenience or low cost, can get amazingly good tones out of a single preamp tube. But the unfortunate majority of musical equipment products on the market were made with convenience and low cost, the bottom line, as their primary design goals. Even reputable brands fall into this trap: one of their engineers may come up with a great new product, but then the marketing and accounting departments tell them “the retail price will be too expensive, and the parts are costly and hard to source, and we don’t have assembly/repair workers trained in handling high voltages. So make it cheaper, with fewer parts, use a standard 12AX7 tube, and make it run on low power.”
To make the accountants and executives happy, a lot of the time these engineers (under pressure for both cost and delivery time) just borrow an existing prefab simple low-voltage 12AX7 gain stage design, and stuff it into whatever preamp or effects pedal the brand is making. So now the brand doesn’t have just a delay pedal, they have a TUBE delay pedal, with thick, warm tones just like the greatest classic-rock guitar solos! Or instead of a bland amp with no great features, now they have a super-versatile dual-function preamp that can give you everything from crisp modern tones to rich, fat vintage tones, at the flip of a switch! Sometimes those proclamations are just hyperbole, where there is a tonal effect but it’s not that great; but too often those claims are outright mealy-mouthed lies. And their whole purpose is to gull you into buying another new product, even if it can’t deliver what it promises. And you know what—they can get away with it, because claims of tone are subjective; so as long as there is “a real tube” in the circuit, the manufacturer is not violating any truth-in-advertising laws.
To complicate matters more, all of these tone descriptions—whether legitimate or bogus—are totally relative. What sounds “amazingly rich and detailed” to one person may be far too subtle for another person to even notice. Imagine you hear someone describing a car they just test-drove, and they say it had terrific handling, impressive acceleration, and better fuel efficiency compared to another car they tested; how do we know their frame of reference? Are they describing the difference between a new Honda Accord and an old Dodge Ram Wagon–or the difference between an Accord sedan DX and an Accord sedan LX? There’s no exaggeration in that analogy—sometimes one product really does sound remarkably different from another, but very often when people describe the difference between tubes, they are describing qualities that the average listener just would not perceive unless they were told to listen for it.
That of course leads straight into the problems of biased perception, that I have mentioned in previous posts. We see and hear what we expect (or hope) to see and hear, almost universally. It is very difficult to avoid these distortions our brains and ears impose on the objective, testable reality. When people “roll” tubes (swapping various different tubes into one piece of music gear), there is almost no way to prevent hearing some very biased and distorted version of the truth—no matter how perceptive and well-intentioned the listener is. When you are just listening for your own benefit, there is no problem with those perceptions, they are as good as reality; the problem arises when you read other peoples’ opinions and claims.
But wait—there’s more! In addition to the real or perceived differences between tubes, and in addition to the question of appropriate voltage and current supply, the fact is any tube gets a large part of its tonal qualities from the rest of the entire circuit it’s built into. Some preamps (for example) are designed in such a way that a Telefunken ECC83 will sound very different from a JAN GE 12AX7 or a modern Chinese generic; while other preamps will sound pretty much exactly the same regardless of what tube you use. Sometimes a careful tube designer will actually choose a specific Chinese or Russian generic 12AX7 and design their preamp around the performance characteristics of that tube, such that “upgrading” to an expensive vintage tube could actually downgrade the performance of that preamp–or at least not result in the positive tone change you hoped for. Also, there’s no one correct understanding of what “tube sound” is anyway—tubes can provide mild grit, subtle warmth, raging fuzz, and even sterile cleanliness! Some of the most high-fidelity sound reproduction systems use tubes. It all depends on the circuit design; so when looking at gear to buy, you have to ask this question: what is this specific product designed to sound like? Just because it has tubes doesn’t mean anything, so is it intended to sound even remotely like what you want?
Bottom line, you can’t make assumptions. Some of the variables are hidden; some of the language is wide open for interpretation; and some of the sellers are liars. Always listen for yourself, and never trust the hype.
