Analog Gear in a Digital World

Many of us often find ourselves mixing in the box using plug-ins in place of analog processors and pushing a mouse instead of riding faders. As a result,

Many of us often find ourselves mixing “in the box” — using plug-ins in place of analog processors and pushing a mouse instead of riding faders. As a result, I sometimes hear engineers expressing a longing for the good-old days of studio production, when their ultimate job was spreading a mix out on a console, inserting some beloved outboard gear (now relegated to a dusty rack in the corner of the control room), and jockeying faders until the mix was just right. Although the good old days aren't coming back, you can interface those favorite pieces of analog gear with your DAW, and they'll give your mix something special that you can't get out of a plug-in.

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FIG. 1: Analog gear can be inserted into a digital audio applications such as Pro Tools by accessing a specific interface input from a mixer channel''s insert points.

Fix It Now

Although many DAW hardware interfaces come with input stages such as instrument or mic preamps, using an outboard preamp is an easy way to improve the sound of your recordings. Simply connect the output of a dedicated mic pre to an analog line input of your audio interface or conversion hardware, and you'll usually hear an improvement. With some interfaces (even high-end ones), the quality of the converters is the primary concern, and the onboard mic preamp may be less than stellar. Tube preamps are noted for their warmth and sweet harmonic distortion, and some solid-state models can provide additional colors that can be useful for your projects.

Many companies offer improved tube circuitry design and make affordable mic pres that are clean, quiet, and warm with high output levels. Quality analog mic pres can be found to fit any budget and any project, from Mackie's XDR preamps in its small-format mixers to the highly regarded “British EQ” in Allen & Heath and Soundcraft boards. If your budget allows, you might opt for a classic reissue such as Universal Audio's LA-610 or a modern “modeling” mic pre like Focusrite's Liquid Channel, which can emulate other circuits, morphing into any number of well-regarded outboard mic pres.

Highly affordable mic pres such as M-Audio's DMP3 and ART's DPS II have made fans of engineers who appreciate the warmth that the units impart to bass and guitar. Turning that formula around, processors that are designed for instruments, such as a “stompbox” compressor or “modelers” like a Line 6 POD, can be inserted in the analog part of the chain to provide a more or less dramatic effect to a vocal as well as instrument input. Inserting a hardware compressor, such as dbx's classic 160X or current 160A, between the mic pre and the converter can give you the kind of unexpected punch that you can't get from a plug-in.

Fix It Later

If you recorded your a rock band through your computer's AV port and the recording sounds wimpy, there are ways to get that analog gear into the mix for a warming trend. I'm often called to project studios to enhance a mix coming directly out of the computer, and I'm always amazed at the racks of outboard gear sitting untouched and unpowered in the rear of the room. Many project-studio owner/operators use the high-end analog gear on input, and then neglect it in the mix, having been seduced by plug-ins.

It's easy, however, to turn your interface converters into “insert points” for your analog outboard gear if you have a multiple-output interface. You can feed a line output from the interface to the outboard analog processor, and return the analog gear's output to the corresponding input on the interface or converter. In your software, insert this loop into the track you are trying to modify (see Fig. 1). You may have to experiment with the input and output levels of the analog gear so that you don't overdrive the gear or the interface converters.

Running a channel through the analog piece can produce the desired effect sometimes, imparting the gear's inherent color to the track. I often insert a vintage channel strip or a compressor into a track (without engaging EQ or compression), just to gain the quality of the circuitry. The new, affordable channel-strip modules that have tube circuits, such as MindPrint's En-Voice MK II ($799), can also be used as separate EQ or compression circuits on inserts to warm up tracks.

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FIG. 2: Recording a processed signal allows you to see the amount by which the unprocessed signal can be offset in order to align the newly processed signal with other tracks.

Because A/D/A conversion takes time, tracks that have hardware inserts can become noticeably latent. Some programs can measure the latency, but it's easy to simply record a bit of the processed track to a new audio track. By comparing the original audio with the processed audio, you can measure exactly how late the processed signal has become. Then you can shift the original audio ahead by exactly that amount of time. After insert processing, the new audio will be time-aligned to the other audio tracks (see Fig. 2).

Another good way to use dormant outboard gear is to run it through hardware aux sends and returns. That works especially well for signal processors such as tape echo and plate reverb. It is also a good way to incorporate outboard digital processors that might not be connected to your DAW digitally. By connecting a numbered audio interface output to your gear and assigning an aux send to that output on the software application's mixer, more than one channel can use the outboard processor. Return the processor's output to an interface input (it doesn't have to be the same number), and assign that input to an aux channel in the DAW (see Fig. 3). I often use that method to take advantage of my classic reverb, harmonizer, and analog filter. In fact, any piece that might work on more than one track gets patched this way. Although that method doesn't work particularly well with compressors or EQs because of latency, time- and modulation-based effects such as reverb and delay work wonderfully.

Do Some Time

Another way to integrate analog gear with your DAW is at the output stage, spreading your mix across many analog faders instead of only the L and R outputs from the DAW. When the budget supports it, I like to do as much of the work on the mix as possible at my desktop studio, and then rent a three-hour block of time at a larger studio (which can cost as little as $300) that has a vintage analog console. (Although I use a mobile Pro Tools rig, you can do the same thing with a laptop and a multiple-output interface.)

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FIG. 3: Analog gear such as reverbs and delays can be accessed by several tracks at once by using a DAW''s aux-send and -return features.

In the first hour, I calibrate the analog desk so that all faders are at 0 VU and unity gain. I then assign each channel in the song file to a separate interface output (maintaining stereo pairs where necessary), re-create the individual panning from my DAW mix, and print that mix. In most cases, the mix already sounds better, because of the quality of the analog summing bus in the high-end console.

Next, I adjust the DAW faders individually to 0 VU, and then I compensate for any changes on the analog desk. For example, if my bass track was playing at -6 dB in my mix, I raise the software fader to 0db and attenuate the console fader by 6 dB. Now the DAW is doing less calculating, and the console is doing the balance work. The sound is even better when I print that mix.

In the third hour, I do some tweaks, swap out my plug-in reverbs for the studio's hardware units, and print the best mix that I can in the time remaining. Total expense: $300 to $500. Sonic improvement: priceless.

Check It Out

So get out the feather duster, find a spare AC strip, and fire up those hardware effects, analog mixers, and weird stompboxes that haven't seen work since Pro Tools 1.0 was in beta release. It doesn't have to cost anything to get back some of the good from the good-old days.

Dave Darlington has just finished recording and mixing a new album for singer Dar Williams. D>Tour's (Darlington's group) debut album is available from Templar Records.