Warming Trends

A warm tropical breeze blows over your body as you float effortlessly in the soothing, bath-temperature waters of the Caribbean. But then you snap out

A warm tropical breeze blows over your body as you float effortlessly in the soothing, bath-temperature waters of the Caribbean. But then you snap out of it, jarred by the unsettling realization that your digital tracks aren't nearly as warm as your tropical fantasy. If anything, they're more reminiscent of the frozen North.

Modular digital multitrack recorders (MDMs), digital audio workstations (DAWs), and hard disk recorders (HDRs) are wonderful inventions offering clean, accurate audio in affordable packages. However, digital recorders typically lack the warm, round sound that analog-tape machines are prized for. Hence the renewed popularity of exotic tube preamps and vintage microphones-devices that can help warm up signals before they enter the cold, unforgiving digital domain.

Of course, shoestring budgets prevent many of us from owning such exalted gear, or from using a studio that does. So we make do with the usual suspects of the personal studio: mass-manufactured mics, cloned circuit boards, cookie-cutter mixing consoles, and preamps featuring a single tube sandwiched between cheap op amps. Come mixdown, we try feverishly to warm things up with EQ and plug-ins. But more often than not, the final cut still suffers from that annoying digital edge, a sound variously described as cold, thin, harsh, and devoid of personality.

But don't despair. Just because your setup is digital doesn't mean you have to settle for a sound that lacks analog flavor. With the following tricks, you can soften digital harshness and add some analog pizzazz during mixdown-without relying solely on plug-ins or going broke buying premium outboard gear.

PLUG-IN DROPOUTFor those using computer-based DAWs, analog-emulation plug-ins (such as DUY's DaD Tape, Waves' Renaissance Compressor, and Bomb Factory Digital's LA-2A) are invaluable tools in the quest for analog sound. Yet, as helpful as such applications are, they still seem plagued by a subtle lack of depth. They're only mathematical models of the real thing-close, but not quite there. However, by using analog-emulation plug-ins in tandem with real analog processors, you can meld the best of both worlds for a truly phat sound.

Of course, for those who work exclusively on an MDM or HDR (for example, a Tascam DA38 or Akai DPS12V2, respectively), software plug-ins aren't an option. Therefore, other avenues to analog warmth must be explored.

SAVED AGAINFor the most part, the following techniques are based on processing digitally recorded tracks with analog gear and then rerecording the tracks to digital. Because this process alters the tracks' sound and sometimes results in excessive or unwanted effects, it is strongly recommended that you not erase your original tracks. You never know when you may need to resurrect them. It may be that you oversaturate a track and it sounds awful in the mix, or perhaps an electrical spike causes an error during the transfer that you don't notice until afterward. Either way, having the original, unadulterated track allows you to start again from scratch.

With DAWs and HDRs, storing tracks offline is a piece of cake. If you're MDM based, make sure your tracks are backed up on tape.

OUTSIDE HELPThe simplest way to introduce analog coloration to digital tracks is to run the tracks through real-world analog units and then rerecord them to your digital multitrack. Simply route the track from the digital source into the analog unit (using a direct output or equivalent) and then from the output of the analog box to a new digital track. This will add some analog distortion-the desirable kind-to the track, typically resulting in a smoother, thicker sound (see Fig. 1).

You can process and print tracks one at a time, so all it really takes is one analog unit. However, variety is always desirable, as each box will provide a distinct "flavor" of coloration, and some signals will sound better through certain units than through others. Therefore, I like to have a number of different processors on hand.

As for the type of gear to use, experimentation is the only way to find out. Preamps are obvious contenders, but most any type of processor will work, including dynamics processors and multi-effect units. The trick is to bypass the processing and let the character of the passive circuitry alone do the job. At this stage, we're after only the essence of the analog machine, not the processing. (Save that for mixdown.)

If the unit doesn't have a bypass switch, set the controls so the signal is least affected. On a compressor, for example, put the ratio at 1:1 and the threshold at its highest setting. On a multi-effects unit, turn the mix knob to 0.

Interestingly, though tube units are generally thought to provide the most desirable coloration, solid-state gear-especially quality, Class A stuff-can do a great job, as well. For example, Tuck Andress (of Tuck & Patti, Windham Hill Records) uses an Avalon 737 compressor on his acoustic guitar tracks at mixdown, "not for compression," he explains, "but simply for tone and coloration."

In general, the better the gear, the better the quality of coloration it contributes to the signal. But that doesn't mean you have to spend a fortune to get something worthwhile. Almost anything with a 12AX7 tube in it will impart some analog attitude. One obvious pick is A.R.T.'s Tube MP mic preamp, which retails for only $139. There are also some inexpensive solid-state pieces that specialize in providing a vintage-type analog sound. For example, check out the Joemeek VC3 Pro Channel ($399) and C2 compressor ($399).

I would also encourage you to look beyond the world of studio gear. Keep an eye out at flea markets and in thrift stores-old stereo-tube preamps can be real jewels. Or try kludging the old with the new: find a vintage tube at a flea market, for example, and pop it in place of the stock tube in your budget processor.

Another cost-effective approach is to rent the gear you need-an especially good option if you want the high-dollar stuff. Most major metropolitan areas have pro-audio equipment rental shops, as well as places that specialize in vintage gear. Get all your tracks together, rent a couple of exotic preamps or compressors (for example, Neve, Urei, and so on), and spend a day rerecording tracks.

MAGNETIC RESONANCEAdding real tape saturation to your digital tracks is a no-brainer. Simply record your digital tracks to tape and then rerecord them to your digital multitrack. The trick here is to hit the tape with enough level to cause saturation-in other words, push those needles into the red! You'll probably need a preamp to get the signal hot enough. Experiment with different levels and listen to the results before committing to a particular sound. Also, pay attention to what the preamp is contributing to the signal-you may find, for example, that a tube preamp coupled with tape saturation results in too warm a sound.

Old open-reel recorders are pretty easy to find these days and can often be had for cheap. In general, the wider the tape head (and tape), the better the fidelity. If possible, use a machine with built-in noise reduction. Hitting the tape with plenty of signal should push the noise floor down sufficiently, but for quieter passages, the noise reduction will further help in keeping tape hiss to a minimum. On the other hand, you may prefer the sound without noise reduction, so it pays to compare.

Multitrack units are preferable for "tape saturating" your tracks because they allow for stereo transfers and provide enough tracks for good SMPTE isolation (I'll explain this in just a second). However, depending on the quality of tape saturation you desire, almost anything can work. Hip-hop producers have long been sampling directly from cassette decks to capture a gritty, lo-fi analog sound.

The best way to transfer tracks is with the tape deck and the digital multitrack locked together. This is where the multitrack tape machine comes in handy. Strip an outside track (1 or 4, 1 or 8, and so on) with SMPTE and make the tape machine the master. You'll need a SMPTE to MTC sync box (for example, MOTU's MIDI Time Piece AV) to make this scenario work. To prevent SMPTE bleed, leave an empty track between the SMPTE track and the track or tracks you're recording to. For example, if SMPTE is on track 1, transfer to tracks 3 and 4.

With tape now sending SMPTE and your digital multitrack locked to the incoming time code, tracks can be flown back and forth between the two units without losing a beat. If some delay or slipping does occur, realign the processed track to the original. DAWs and HDRs have extensive cut-and-paste capabilities, making realignment a breeze.

To correct timing problems on MDM systems, use the sync box's SMPTE offset capability in combination with your MDM's track delay (built into most newer machines). To do this, set the offset so the processed track lays a hair early and then use track delay to nudge the track into time.

If you don't have sync capabilities, don't worry. Just fly your track to tape, ballpark a start time, press Play on both machines simultaneously, and rerecord the processed signal to your digital multitrack. With a bit of time spent cutting, pasting, nudging, and delaying, you'll be able to realign the track. Using the original track as a reference, align the processed track to it. You'll rarely get an exact lock, but you can tell the two tracks are extremely close when you hear flanging. This is, admittedly, a tedious procedure, but it lets you grab tape saturation from practically any machine, including portastudios and 2-tracks. Just bear in mind that cassette decks and other narrow-tape formats won't have the fidelity that a professional multitrack tape machine has.

NOISE IN THE HOODIn the past, generation loss and added noise from too many transfers was a real concern. But with today's digital machines, it's hardly an issue. Their quality converters and low S/N ratio allow for multiple analog transfers-at least two or three-without adding noise or causing noticeable signal degradation. Any noise introduced will most likely be from the analog processors, not from the digital equipment.

When noise does creep into the signal, whether it's tape hiss or tube hum, you can zap it in a variety of ways. If you're working on a computer, noise-reduction plug-ins such as Digidesign's DINR or Arboretum's Ray Gun are typically the most effective. If your tracks aren't in the computer, you'll need to use more traditional strategies. Noise gates work well with sharp transient sounds; downward expanders are better suited to signals with long attacks and decays. Parametric EQ can be useful for notching out some noise, but apply it judiciously so as not to spoil the sound of the instrument.

A favorite trick of mine is to print a track of the analog noise alongside the processed signal and then reverse the phase on the second track. By adjusting the gain between the two tracks, you can use phase cancellation to greatly decrease the analog background noise while leaving the original signal intact. This is a cool trick, but it works well only on noise that doesn't fluctuate.

A new breed of tube preamps has arrived on the scene, with digital connections either built in or available as mods. These machines are nice because they let you keep everything in the digital domain, minimizing possible noise from multiple analog I/O stages. The catch with these units is that sound quality is dictated entirely by the unit's internal converters-if they don't sound sweet, neither will your tracks. A reasonably priced unit that sounds good is MindPrint's En-Voice ($998 with digital I/O option; $749 without; reviewed in this issue).

AVOID GLOBAL WARMINGFor the best results, warm up only those tracks that are key to giving your mix an analog flavor. It's not necessary to process every track. After all, some instruments in a mix just aren't loud enough to make much difference, and others are so processed with EQ and effects that the subtleties of analog coloration are lost. Also, too much tape and tube saturation on too many tracks will result in a muddy mix. By processing only the most conspicuous instruments, you reap the best of both worlds: the analog-processed tracks impart body and character while the digital tracks maintain premium fidelity and separation.

My first analog pass typically includes lead vocals, kick drum, bass (usually bass guitar), and the main comp instrument (usually acoustic or electric guitar). Every song is unique, of course, but in most pop music, these instruments take center stage, defining the sonic signature of the mix: the lead vocals are the focus, the guitar covers the midrange, and the kick and bass fill the bottom end. With different material, I may warm up other-or additional-tracks. The trick is to process only the key tracks, so that the overall impression of the song is analog.

If you want to go a step further toward an analog sound, take your DAT master, before mastering, and run it to a vintage analog 2-track tape machine (for example, an Ampex ATR 1000 1 1/4 2-inch deck running 30 ips with Dolby SR noise reduction). Depending on the mastering facility, you can then perform the mastering directly from the 2-track analog master, or you can record from analog back to another DAT.

TO WARMER CLIMESDigital is great, but as many of us have discovered, analog has certain inherent charms we are not content to live without. Thankfully, we can enjoy them without giving up the quality, convenience, and affordability of digital. Armed with one or more analog processors, you can add true analog warmth to cold digital recordings.

The rerecording techniques described in this article are not new, but used specifically as a way to warm up digital tracks, they are somewhat unorthodox. But who cares? Be creative in the pursuit of new sonic flavors and colors. This is what distinguishes a good producer/engineer from an excellent producer/engineer. The tools are there. It's up to us to make them produce the sound we want-rather than have them dictate the sound we get.

Erik Hawkins is a musician/producer working in Los Angeles County and the San Francisco Bay Area. You can check out his fledgling indie label at www.muzicali.com.