The following excerpt comes from MIXERMAN Musician’s Survival Guide to a Killer Record
Have you ever listened to a Motown record from the sixties and heard the obvious distortion on the vocals? That distortion is from the preamp. How do I know? Because I know analog preamp distortion when I hear it. It has a particular sound.
I mean, there are a ton of different kinds of distortion. There’s breakup. There’s gain. There’s crunch, spit, buzz, sizzle. There’s low-end distortion which can be woolly in nature. There’s bit distortion, and there’s clipping. And each of these distortions is useful in its own way, and when you have control over the kinds of distortion that you introduce, you have control over your record.
The distortion properties of a vintage preamp is probably the single biggest factor in their value. If you wonder how a preamp could be worth $4000, it’s because no other preamp distorts like that one, and there are enough people who have benefited from that distortion over the years to justify the expense.
It’s not just the overt distortion that occurs from pushing the gain all the way. It’s the subtle thickening that occurs moments before breakup that is often so desirable. And while this is technically distorting the signal, it’s not necessarily heard as distortion.
As far as I’m concerned, no preamp is worth that kind of money, that is, unless money is no object. And if money were no object, I’d own all sorts of expensive things. But let’s be real here for a moment. The preamp won’t fix a shitty song. It certainly won’t fix a lackluster performance. Besides, we are finally entering an era in which digital distortion algorithms are convincing and pleasing, even when sickly aggressive in nature.
Now, there are five reasons to introduce distortion to your production: sustain, clarity, obfuscation, thickening, and agitation. First, let’s define some flavors of distortion, and explain where they shine.
We generally seek to avoid clipping from our hardware, as it manifests itself so nastily it can reflexively cause you to duck. There are times when controlled clipping distortion might be desirable, but in general, I only use this kind of distortion if my goal is to agitate. As I pointed out earlier, it’s always best to derive your clipping from a plugin and not your converters so as to maintain control over it.
Bitcrusher distortion is also exceptionally nasty distortion, in which the audio is downsampled in order to produce a lo-fi tone. The lower the bit rate, the more obvious the artifacts of aliased high-end frequencies, which present as spitting and noise. The bitcrusher can offer a very cool effect, but it’s exhausting to the listener, and even if your goal is to agitate, you might want to demonstrate some restraint with how much bitcrushing you apply to any given production. That said, it’s a very cool effect. The more low end in your production, the more tolerable this kind of distortion will be.
Total Harmonic Distortion (THD)
This is the measurement that manufacturers tout to get you to purchase their gear, and it’s more commonly expressed as THD. It’s not a particularly meaningful number, since we often go out of our way to distort things. Anytime someone points out distortion specs, my response is always the same. Distortion, dismortion! Yeah, we want to limit distortion when it’s a problem. These days you’re more likely to introduce it than to avoid it.
Overdrive is probably the most useful and common distortion of them all as it’s not overtly aggressive in nature, which allows you to retain some modicum of your dynamic range within the part. In other words, you’re not obliterating the signal as you break it up. Overdrive is often used in conjunction with filters, in particular LPFs (which allow the low end to pass), in order to reduce the strident nature of the distortion. High frequency overdrive is meant to be grating. Low-mid and low-end overdrive acts as a thickening agent.
Crunch distortion is used to describe high-gain electric guitars. Oftentimes a crunch guitar plays power chords which requires sustain. This distortion is typically derived from an amplifier or pedals–virtual or otherwise. Crunch distortion shines in the upper midrange. The rock, metal, and pop genres often call for crunch guitar.
Buzz distortion acts like a separate layer over the source. As such, it typically only affects a somewhat narrow frequency band. Its resonance puts a definitive edge on anything that sustains, and is used to provide clarity. Buzz distortion is especially useful for clarity on low-end instruments like a clean synth bass, or even a sustaining electric bass part. The buzz brings out the upper harmonics, which helps the notes remain audible throughout the production. This is a particularly common distortion in Industrial music.
Fuzz distortion affects the full range of frequencies, which makes it somewhat more complex in nature. Unlike buzz, the delineation between the tone and the dirt is not so evident. Whereas buzz offers clarity, fuzz can offer either clarity or obfuscation, since it distorts the entire signal. When it comes to bass, you can add copious levels of fuzz distortion for purposes of edge and clarity. Fuzz distortion introduced in a subtle way can appear woolly in nature.
Distortion of the low frequencies often comes off woolly. Used aggressively, it can start to sound unstable, as the low-end energy causes an especially dirty breakup. Used judiciously, woolly distortion can be relatively inaudible beyond a slight bit of breakup in the low end, which is often masked. Rock Bass guitars love woolly distortion, although they can consume your entire mix when used too overtly. Kik drums react well to woolly distortion too. While it’s true that woolly distortion can add clarity for transient instruments, it can also obfuscate instruments that sustain.
Tape saturation plugins are merely distortion plugins. The effect is supposed to emulate the sound of hitting tape too hard, but they’ve become almost cartoon-like in their modeling. The sound of uber-aggressive levels to tape was typically used as an effect, not as a matter of course. Most of us used tape for purposes of fidelity. But there were some engineers (especially in the nineties) who virtually claimed the overt sound of crushing tape on all of their records. As if that was ever a popular sound.
Tape saturation distortion supposedly models odd harmonic distortion which is, indeed, the kind of distortion you can expect from a tape machine. Basically, a saturator distorts the early odd harmonics. Don’t ask me how or why the early odd harmonics distort from tape. I couldn’t tell you nor do I care. All I know is I’ve never heard a tape saturation plugin that actually sounds like tape, likely because they’re all way too overt in how they schmear the sound.
Some people claim to put tape saturation plugins on nearly everything, and that’s a great way to turn your production into a woolly mess lacking any kind of clarity. Don’t believe for a moment that tape saturation plugins have anything to do with the sound of analog tape. They really don’t.
I adore the sound of tape given that it reproduces far more musically than the digital platform. Yet, I can’t stand the sound of most tape saturation plugins given how unmusical they are. Call me crazy, but I don’t typically go out of my way to be unmusical in my decision-making. My advice is to use tape saturation sparingly, purely as a way to add distortion.
I would be remiss were I not to mention, there are some tape machine modeling plugins that are meant to offer the sound of tape. These can offer good things, and should not be lumped in with tape saturation plugins, which are designed to mangle the tone.
Saturation distortion is like tape saturation on steroids, which is actually far more useful as it gives you considerably more control over the tone. It allows you to absolutely drench a part in overt distortion, but it can also be used in more subtle ways. Saturation plugins can be extremely useful, and are a staple in modern pop music at the moment. Don’t let that dissuade you from using one.
Spitting distortion can be derived from any frequency range and produces a feeling of instability as the breakup is almost random in nature. The spitting distortion can at times sound like digital pops, mixed in with some other kinds of breakup distortion.
Tubes, sometimes called valves, introduce even-order distortion, which is supposed to be less musical than odd, but I’m not even sure I know what that means anymore as I personally find tube distortion to be rather pleasing in nature. The beauty of tubes is they can absolutely sing if given enough level, making them excellent for sustain. Valve distortion is often described as “warm,” as it resonates most apparently in the lower midrange, and therefore, acts as a thickening agent. It’s particularly effective at providing sustain, without overt top-end distortion, although you can certainly get a tube to buzz if you desire.
Tube screamer distortion is an emulation of valve distortion, and is derived from a pedal. They are often used to inject more gain to an amplifier for purposes of sustain. Tube screamers tend to filter out the top and bottom end, placing them squarely in the midrange. As a result, they can make power chords sound downright small, but they can be quite useful for apparent midrange.
Breakup is mild distortion in which there is minimal sustain and resonance. Breakup is effective on virtually any instrument, including vocals. Electric guitars that are too clean in tone can sound downright anemic, and often do well with a touch of breakup. It’s still a clean guitar, it’s just that now you’ve added a little spice to make it pop in the production. Breakup can be derived either with a guitar amp, preamp, or plugin.
Now that we’ve established the importance and diversity of distortion properties, we should probably discuss levels of distortion. How much distortion is too much distortion?
It depends on the production, of course. Some productions call for distortion on virtually everything. Others call for very little overtly audible distortion. But you always want to introduce some measure of distortion.
So, where’s the line? You can make the track pure white noise if you think it’s going to sell records. Excess distortion is a matter of taste and would fall under artistic license. Too little distortion on the other hand is a technical issue. Because you never actually want too little distortion. A record without distortion is like food without seasoning. It lacks flavor.
Throughout the history of recording you would have to go way the hell out of your way to record too cleanly. You would need preamps with exceptionally low distortion specs, which you would gain super conservatively. You had to avoid most EQs, or at least you had to avoid EQ boosts, particularly in the high-end frequencies. You had to choose compressors that had super low THD specs. Of course, none of that changed the fact that you introduced distortion when you went to tape. And then there was the consumer’s turntable stylus, which would also introduce distortion. For most of my career it was actually difficult to avoid distortion.
When it comes to distortion, the mic pres that come in interfaces generally don’t help matters. I’m not going to malign interface pres as a group as they’re not unuseful for home recording, and they’re rather prevalent to boot. You just need to understand how they distort, if at all. That said, as much as you might prefer to introduce some distortion at the mic pre, there are other stages from which to derive it.
You should choose your distortion based on your production needs. If I’m mixing a dense production, and I find it difficult to make the bass note movements audible, then I can use distortion for purposes of clarity. If my part is transient in nature, and in need of either some thickening or punch, then saturation can help with that. Gain on a guitar amp will provide distortion for purposes of sustain and edge.
All distortion can be made to agitate, which probably has more to do with the ratio of top-end information than any other factor. Pleasing distortion tends to roll off at the top end, and the distortion of the upper harmonics provides us with clarity. If copious levels of upper midrange and top end are a part of the distortion makeup, agitation will undoubtedly be the result.
Kik drums are routinely distorted in my productions, and you might not ever even notice. That’s the thing about low-end distortion. It’s not necessarily audible in context, and often acts more like a thickening agent. Sometimes I want to hear the distortion on the kik drum, but then that’s often for purposes of edge. I’m also often using distortion in conjunction with compression to assist with punch.
I suppose the big takeaway is this: If your equipment isn’t introducing enough distortion, and your production sounds anemic, lacks edge, punch, or clarity, then you can use distortion to help with any and all of those maladies.
People love this book! There are tons of five star reviews on Amazon. Larry Crane of TapeOp raved about it: “I think I’ll be buying cases of this book and handing it out as people enter my studio.” Why would a studio owner/ recording engineer (and publisher) give a book on recording to his clients? Because the more his clients understand about recording, the easier his life becomes. That’s why.