Analog Analogs: Approximating Vintage Sounds In the Box

For many, the age of digital audio is also an age of analog nostalgia. Despite the ever-increasing quality of digital audio systems, all those decades of listening to the non-linearities of tubes, transformers, and tape have biased our ears in favor of older, more colored, and more costly recording methods.

Unfortunately, fewer and fewer of today’s projects have the budgets to track to tape and mix on a large format analog console, coupled with racks upon racks of vintage outboard gear. But that doesn’t mean you can’t capture some of that old school vibe while working within the box.

To shed some light on how to best bridge this gap, I spoke with a veteran of both the analog and digital domains, Grammy-winning producer/engineer Chris Shaw, who has worked with Weezer, Bob Dylan, Public Enemy, Nada Surf and countless others. While he prefers working on a console when it’s an option, Shaw is an adaptable pragmatist, interested in getting the best sounds possible, whatever the constraints. His “in-the-box” mixes are among the best.

First, Know Your Gear

Right off the bat, Chris concedes that working in the box might never sound exactly like working on an analog desk. And, while there’s a wide variety of plug-ins designed to emulate various pieces of classic hardware, getting close to their original sound also depends on the user, and his familiarity with the original unit: “How does this EQ sound? How does that compressor react? How much can you push a plug-in before it breaks up in order to hit that analog sweet-spot? You have to know what the original does to know what the emulation is supposed to do.”

Chris Shaw

People have plenty of naive assumptions about analog gear (who among us hasn’t had a client assume that the “warmest”-sounding preamp in your rack will be the one with a tube in it, sound unheard?). But a little experience can clear up a lot of pre-conceived notions. Shaw recommends we “Beg, borrow, and steal as much gear as you can, learn it. Playing with emulators is kinda hunting in the dark. Read as much as you can.” It’s good advice, and I can personally attest to how helpful the experience of aligning a tape machine has been when configuring settings on a tape saturator.

And there’s more to the matter than just getting acquainted with specific pieces of gear. Analog know-how is important on a macro level as well, and a solid understanding of signal flow can be critical to getting a convincingly “analog”-sounding response.

Whenever various types of saturation enter the signal path they’ll be doing so at different points along the chain. It pays to be aware of what comes when in a conventional analog system. If you are looking to conjure up classic tones, you may want to start by making sure that the order of your plug-ins remains true to that real-world signal path. This means you’ll want to understand at what stages coloration from preamps, tape, mixing desks and outboard gear traditionally enter the picture.

The next piece of the signal-flow puzzle is commonly referred to as “gain-staging,” the process of making sure the levels along your path are correct to drive your processors as intended.

For many people, the focus of digital recording is to get the signal as hot as possible without clipping, but levels recorded to tape will often vary more according to the source: Toms are often printed to tape with a level on the hot side of things in order to take advantage of the natural compression, while overheads are likely to be printed conservatively in order to preserve transients. Keeping this in mind can help you get the most convincing response from your analog-style plug-ins.

Analog” Mixing In-The-Box

The most common place to emulate analog is probably in mixdown. The first part of this process for many of today’s top in-the-box mixers is a subtle but important one: emulating a console’s channel strips.

Before they even bring up any of the faders, mix engineers like Shaw will often select an emulation plug-in and place instances of it as the first insert on each of their audio tracks. If you’re sub-mixing tracks (as with multi-mic’ed sources) to a single bus for processing, you may want to put a console emulation on the first insert of the aux track that you’re bussing them to instead.

Some good plug-in options for this are any of the console emulators from UAD, as well as Slate’s Virtual Console Collection, NLS from Waves, and even the older McDSP Analog Channel 1. While the effect on each individual track may be nearly indiscernible, bypassing all instances at once often reveals the night and day effect this can have on your mix.

One additional caveat: when adding console emulation (or any other type of saturation) to stereo tracks, it’s advisable to use multi-mono versions of these plug-ins. Saturators get more aggressive as you drive them, and many stereo-linked versions will apply saturation equally to both channels based on the hotter of the two channels, rather than independently, as would occur if the signal were routed to two separate channels of an actual console.

The key is to mix with these plug-ins just as you would with a real console: by basing your mix decisions on the sound of the colored audio, rather than just tacking it on at the very end. Applying the same kind of subtle coloration to each individual track can provide a great deal of sonic cohesiveness that, in Shaw’s words, “Gets the mix 10% closer to finished before you even start.”

If you’re feeling adventurous, an advanced variation on this is to emulate different consoles for different instrument groups (Chris Shaw’s own method is to use Slate’s VCC Neve setting on drum and bass channels, the API on guitars, and SSL on vocals).

Universal Audio's Ampex ATR-102 Emulation

On the other end of the signal chain, you can apply saturation to your mix bus as well, by emulating the sound of mixing to 2-track tape. UAD’s ATR-102 Mastering Tape Recorder, Waves’ Kramer Master Tape, and McDSP Analog Channel 2’s Japan-S setting are all options here, depending on what kind of machine you wish to simulate.

You don’t necessarily want to mix through this the entire time. “I’ll usually put that on somewhere from a third to halfway through a mix, after mix bus compression,” Chris Shaw tells me. “I like to get the drums and bass going on their own first, and apply [master] tape saturation on the whole thing once the rhythm section is solid.”

Often enough, a console emulation on the front end, plus a master tape emulator on the mix bus will be enough to breathe some analog life into your digital tracks. But if you find things are still a little too cold and brittle, adding a multi-track tape emulator ahead of the console emulation on the tracks in question can fatten things up further. You’ll likely want to adjust the gain on each individual track to apply the right amount of saturation for the source, while making sure that the head type, speed, bias, tape formulation, and any other parameters that affect the response curve remain the same on each channel.

Making Virtual Instruments Less Virtual

My conversation with Chris regarding ITB mixing confirmed some of my suspicions and it planted some new ideas. While Chris well-covered mixing in the box, I’ve come to value a complementary approach of my own that comes before the mix evens begins. It’s a technique I’ve evolved while working on productions involving virtual instruments, amp sims, and the like.

The idea here is to simulate the studio signal path in the box, while recording. To do this, I create both an aux track and an audio track for each source I’m tracking out. If you’re familiar with running a console in split-mode, this is basically the same principle. I’ll then route the output of a virtual instrument through the aux, and then on to the audio track (making sure to enable “input monitoring” on the audio tracks I’ll be recording to).

Once the routing is set up, you can create your virtual signal path on the aux track. After the source instrument, the processing chain proceeds just like an analog signal path, beginning with pre-amp saturation (be it of the tube, transformer, or transistor varieties), through EQ and dynamic processing, and finally to tape saturation (experiment with what sounds best, but don’t feel obligated to play with every parameter here).

Stage the chain as you would in the real world, and when you’ve got the sound you’re looking for, hit record and track your sounds through the auxes on to the audio tracks. (Be aware of your compensation settings to make sure you don’t have sync issues later).

If you’re using amp simulators on a DI’ed signal, the process is pretty much the same, with the amp sim as the first insert on the aux track. For a multi-mic’ed approach, you can even designate a separate aux track for each mic. This way, you can copy the amp simulator to each of these auxes, and then change the virtual mic on each aux.

Once you’re done, you can clean things up by making your auxes and source tracks inactive and hiding them. By doing some initial tone shaping this way, you can bring some analog-era commitment into the digital age, and save DSP during the mix as well. If you need to fix something, you can always go back to the unprocessed source later.

To make things even simpler, Universal Audio has built this kind of functionality into their UAD Apollo interface, allowing you to easily commit to convincing analog emulations of classic gear while tracking. That’s probably something we’ll see more of in the future. I can’t tell you if Shaw would approve of this approach himself, but for me, it’s been a good way to bring an analog process into computer-based studios.

Final Thoughts

While all these can be helpful techniques for working in-the-box, this is not to say that you should blindly treat your DAW as though it were an analog machine. Shaw puts it best by saying, “Being a purist doesn’t make sense when using emulation. If you were a purist, you wouldn’t be working in-the-box in the first place.”

As “pure” as the added noise and distortion of analog may seem, there are times when you might not want to dirty your mix unnecessarily. Digital audio offers significant advantages over analog in the noise department, and plug-in emulations often offer the option of disabling unwanted noise sources like AC hum and tape hiss, in addition to adding additional degrees of control over factors like head bump, tempo locking (for delays), and other parameters that go beyond the limitations of physical gear.

But as much as re-creating old-school analog signal flow in the box can help lead us to create familiar and emotionally moving tones, chasing these values shouldn’t necessarily tie our hands together either. Don’t forget those plug-ins that live solely inside the box (Melodyne, Trash and UBK-1 leap to mind). It may be self-defeating to get hung up about using a great plug-in just because it isn’t analog-based. As Chris Shaw says: “Good plug-ins are all valid, put it wherever it works.”

Like Chris, I’ve found that recreating the quirks and charms of analog signal flow in the box can have a huge impact on your mixes. But a final factor that can help tremendously is bringing analog workflow into your DAW-based mixes by adding physical fader control to your system. Having a controller can open up your mix process and make it tangible.

Working in-the-box means never having to leave the sweet spot to make a patch or turn a knob, keeping the focus on making great music, which, after all, is the goal. Introducing a physical control surface can take that one step further, removing your concentration from the visual stimulation of a screen, helping to make that shift in focus complete.

Gavin Skal is a freelance audio engineer, sound designer, and producer based in Long Island City, Queens.

This entry was posted in All Stories, April 2013, Beyond The Basics, Featured Stories, Guest Posts, Technology. Bookmark the permalink. Both comments and trackbacks are currently closed.
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