How a Workhorse Tape Machine Plug-in Preset Came to Be

Even among the grand technocrat class of top engineers, recording, mixing, and mastering ace Richard Dodd (George Harrrison, Travelling Wilburys, Tom Petty) is counted as an especially encyclopedic mind. As the man at the mixing and engineering helm of records as diverse as Carl Douglas’ 70s‑smash “Kung Fu Fighting,” Clannad’s “Theme From Harry’s Game,” and Tom Petty’s acclaimed album Wildflowers — for which Dodd won a Grammy award, his first of five, for Best Engineer — Dodd's ear is fairly unerring.

With his bird’s‑eye view on four decades of changes in music technology, Dodd is the perfect man to unpack the secrets of his own workhorse presets for the UAD Ampex ATR‑102 Mastering Tape Recorder plug‑in, a much-loved modern tool which he played a role in developing and refining. Here, Dodd unpacks the key elements of his “468 15IPS” preset.

What were you going for with your Ampex ATR‑102 Tape Machine preset, “486 15IPS?”

I wanted as little compression as possible, and simply more of the color and warmth of the tape, rather than that sort of limiting and compression effect that the tape will give if you push it hard. In general, 1" tape doesn’t do any of the things that people expect from tape. But you can still get that warm EQ curve without any clipping.

You have the "Noise" and "Crosstalk" functions off. Why?

This preset is all about just the color of the machine and the tape, without the dynamic properties, or any cloudiness or noise. "Crosstalk" is off because it basically narrows the stereo image, and if I wanted my stereo field to be narrower, I would make it narrower. And of course, noise is noise! The sound of tape is wonderful, yes, but the hiss generally isn't, especially on quieter material.

Why do you have "Repro" control more or less all the way up?

By sending the maximum signal to the "Repro" head, I’m able to reduce the dynamic influence of the tape and avoid any clipping whatsoever. So I can leave the dynamics as natural as possible. The input level is much more sober, a bit like what you’d call “under-recording,” which you wouldn’t do on the real tape machine because you’d get too much noise. I have a choice on the UAD Ampex ATR‑102 plug‑in. So I turn it off.

The preset just acts as a coloring device for my mix or any source. I’ve got the color of the transformers and I’ve got the color of the tape and that’s it. By keeping Repro at 10, you’ve got a signal where the dynamic of the source is less affected by the plug‑in.

You’ve chosen “CCIR” for the Emphasis EQ, rather than "NAB."

Those EQs were basically noise reduction systems. They were meant to optimize the sound of the tape, given a standard program source, so basically, on the lower speeds, it would try to emphasize the high‑end going to tape, and reduce it on the way back — keeping in mind that the lower speeds were greater for low-end frequency response. The "CCIR" setting gives you the option of simply making it less noisy at 15IPS. In this case the CCIR ‘model’ sounded better.

I confess, I'm a bit mystified by what the "Bias" control really means in the context of a tape machine like the ATR‑102. And yet, I suspect it’s a powerful function. How should one think of it?

Bias, on a real tape machine, is a constant high frequency being recorded, and we’re really talking high. Around 100kHz. Now, that is there while you’re recording in order to "excite" the magnetic tape's particles and electrons. To get them moving, if you will, so when you tell them where to go, they’re already up, exercised, and stretched ready to go.

This is not a white‑paper explanation, obviously, so you’ve got this very high-frequency energy there, created by the machine, and specific to tape, and it gets the tape ready to record something.

Now, each tape has a different level of how much of that bias frequency is needed to optimize its readiness. And the speed of the tape also affects how much bias is required. A slower tape speed is going to require more, for example, and a higher speed is going to need less, or vice‑versa in some cases. So you get that particular tape and tape speed optimized to be ready, everyone is lined up and ready to start the race, they’ve all got their knee down and the same type of shoes; you can then line the machine up in terms of the frequency: 10k, 1k, just to make it flat.

Now, if you suddenly adjust that bias, everything else you’ve put into place is going to be wrong. If you now take that bias and turn it counter‑clockwise, for instance, you’re “under‑biasing” the tape.

How can you use the "Bias" control on different sources, say, a snare drum or guitar?

On a snare drum, for example, you can lower, or “under-bias” to create an effect like you’re loosening the snares, giving it some "fizz" as it comes to life.

If you go too far, however, you’ll get a lot of distortion and a thin crappy sound. On the other hand, if you start at the normal bias setting, and then go clockwise with the Bias control, the exact opposite happens, and your snare becomes richer, less bright, warmer, and thicker.

That’s something you might find really useful on a poorly recorded electric guitar, which needs some more “reality.” If you try to warm up an electric guitar by rolling off high end, say 10kHz, it doesn’t really do anything, because that frequency doesn’t really exist on an electric guitar. But by using the "Bias" control on the ATR 102 plug in, it’s almost like you’ve moved the mic on the speaker for that EQ tweak. It’s fantastic.

In essence, bias is a constant that is required to make a given thing optimal. If you’re changing this key factor that makes a device optimal or “ready,” the landscape changes. Remember our runners at the starting line, all optimized and wearing the same cleats and in the same position? You change the bias, you’ve just changed the length of everyone’s spikes, or put them in different starting positions, or even changed the surface they’re running on. Same runners — your source sounds — but you’ve completely changed the race.

Now, it's possible — but generally undesirable — to do this with real tape. But with the Ampex ATR 102 plug-in, you can even automate changes to the "Bias" control in real time! I mean, who does that, right? But now you can. Again, UAD has made the impossible, possible. Brilliant.