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Universal Audio Plug-Ins

Models of Classic API EQs and Teletronix Leveler

These plug-ins accurately model API’s legacy 550 and 560 EQs, including the signature API electronics.

I have been a longtime user of UA’s DSP Accelerator cards, and I must say that a lot has changed since my first one in 1999. The emulations have grown beyond simply capturing the response curves to modeling the entire signal path of its hardware counterpart. I ran the review of these new plugs on Sequoia 12 running on a Windows 8 64-bit machine with all new SSD drives.

API EQ Collection

The New API EQ collection (see Fig. 1) comes with two models: the 550A EQ and the 560 Graphic EQ. Download, installation and registration went smoothly. Both EQ emulations modeled the entire signal path, including the famed API 2520 op amps and transformers. The 550A starts with a straightforward 3-band EQ. Each of the three bands uses a dual-knob step switch to dial in either the center frequency or boost/cut, and the high and low bands can be independently switched from Bell to Shelf. The 550A also includes a single switch to engage a Highpass/Lowpass filter that is preset to 50 Hz and 15 kHz. The 560 EQ is a 10-band graphic equalizer. On both units, there is an EQ bypass button, allowing users to skip the EQ filters but leave the component modeling active.

Moving the controls on the 550A can take place a few ways, either by clicking on the corresponding frequency you wish the control to point to or by moving the knobs, which felt awkward because it moves as a switch jumping to the next value. You can also use the “+” and “-” markers above the knobs for boost and cut. Below the band section of the GUI is the Filter switch—default is out, or to the left. Having the HP and LP filters on a single switch, as the hardware was originally designed, may have been good for use in broadcast back in the ’60s, but for music production, it’s a bit of a letdown that these are still tied together.

Below the Filter switch are the two shelf switches for the high and low bands, giving you the ability to change from Bell to Shelf. The bell shape on this EQ has a very useful and musical quality to its geometry. With small amounts of boost or cut, the bell is wide and smooth-sounding, broad, and musical. As you increase the boost or cut, the center frequency becomes predominant, and the bell shape narrows. With the high or low band in Shelf mode, the center frequency that you have dialed in becomes more of a suggestion, as the shelf seems to extend far beyond. For example, with the low band set to 50 Hz, boost it +12db in Shelf mode, and you will hear boosting happen up to about 200 Hz.

The 560 Graphic EQ was a pleasant surprise. They left my studio when I was 17 and learned what a parametric was, but now I am in love with the shaping, the interaction between bands and the low end. Dropping this onto a kick drum track was an ear opener—so much bottom end and yet still tight. Moving the frequency sliders is simple, and Control-clicking on the slider returns it to zero. You can also reset all 10 bands by clicking on the zero at the top of the plug-in.

The API EQs are known for their punch and low-end tightness. Part of that comes from the EQ’s band shaping, but also from the components inside the unit. Bypassing the EQ but leaving the plug-in on, you are able to hear the sound shaping going on. I placed a 550A or 560 on every track that didn’t have EQ and instantly heard a familiar sound—a more vibrant and upfront track. But if I had a dozen of the hardware units, they would all sound slightly different, and I believe perhaps the outcome would be even more drastic.

I like to consider these types of EQs as being hard EQ. You are given strict choices, specific frequencies, and you gain boost/cut in steps, so you are forced to use either +2dB or +4dB; there is no middle ground. The 560 of course gives you a slider for boost/cut, but it is a very small window for ±12dB. The frequency choices are set, too. If you want to boost 150 Hz on the 550A, the only way to do that was to add a second EQ to the mix.

We have come to expect a certain level of quality from UA, from the sound to the graphics to the company’s faithfulness in re-creating digital wonders of the real thing. When opening the API 550A EQ for the first time, the size and look of the plug-in is perfect, matching the hardware version to the point of making you want to reach for the knobs. But do we need another EQ collection? I believe it comes down to taste and workflow. Being able to have an API vibe across an entire mix is fun, and the results are tight and upfront.


On a rock track with two guitar parts, or really any time you have two of the same elements, place a 550A on one track and a 560 on the other because each plug-in addresses different fixed frequency bands. It’s easy to get a huge sound.


Company: Universal Audio

Product: API 500 Series EQ for the UAD-2 platform

Price: $299

Pros: Excellent-sounding EQ; captures the classic perfectly.

Cons: EQ gain steps and a very stylistic workflow limits its usefulness.

These three modeled plug-ins from the 1960s hardware are completely different in attack and tone.

Teletronix LA-2A Collection

The LA-2A plug-in (see Fig. 2) has been updated with the entire signal path of the hardware unit—that is, tubes and transformers were added. UA decided to not only add the entire signal path, but to also more accurately model the compression curves using the knowledge of modeling gained over the last decade of R&D.

The end result is an amazing re-creation of three different units spanning the different incarnations as the hardware unit evolved: the original LA-2 from the early 1960s, the LA-2A Grey from the mid-1960s, and the late ’60s LA-2A Silver. (There is a complete history of the LA-2A on the UA Website.)

The units are categorized by their response and tonal characteristics. The LA-2 is the slowest of the three, giving a gentle attack and long release times, resulting in a smooth feel to the compression. The LA-2A Grey has slightly more top end than the LA-2, with more intermodulation distortion going on as a result of the quicker attack and release times. This faster time restraint brings a nice warm and fuzzy feel to the sound. The LA-2A Silver is the most modern sounding of the three, with a beautiful tonal range and just the right amount of warmth mixed with hi-fidelity to its top end. It does have the fastest response time of the three, but that’s not to say it clamps down on the sound; in fact, it’s the opposite. It has an amazing ability to simply control the content and at the same time add a desired tonal enhancement to any sound source you put through it.

They all give a rich, almost hi-fi characteristic to the sound. With the Peak Reduction control set to 0 (Off), you can hear the sound of the unit’s modeled tubes and transformers give a light dusting of harmonic distortion to the midrange and a sheen to the highs—a perfect addition to your mix bus to breathe life and depth to your DAW.

The LA-2A is the easiest to operate with a simple “how much compression do you want” knob on the right and an output volume to the left. UA has also included the Emphasis adjustment, another throwback to the broadcast days that adds a HP filter to the detector’s signal path.

After spending so many hours using the original UAD LA-2A plug-in, I was eager to try the new versions on everything that I had previously used the original on to see how it compares. When the new 1176 collection came out, I had to readjust my use of the 1176LN. I knew the original plug-in so well that it has taken me a while to get used to the new version. The LA-2A Silver, which is the version closest to the original LA-2A plug-in, does react differently, but the adjustment curve in my mind has been easier.

Comparing the new collection to the original LA-2A plug-in is like comparing my minivan to my Mustang: They both get you where you want to go with good results, but the Mustang gets you there with a big smile on your face. The LA-2 has such a slow recovery time that it really lends itself to a specific rhythmic dynamic from the sound source, while the LA-2A Silver tends to be more universal. Silver also has a sound that is more modern—nice round and woolly lows and beautiful sparkle to the top end. Loading up the original LA-2A plug-in and comparing it to these new emulations showed me just how far plug-ins have come. It’s a whole new ball game.

I really enjoyed loading up the LA-2A Silver on all the tracks I have come to love using a hardware LA-2A: kick, snare, bass guitar and Rhodes. The plug-in simply does what the hardware is famous for. They are emulation perfection.

Tim Dolbear is a Texas-based audio engineer.


On a vocal track, load all three LA-2A plug-ins, plus the original if you want. One at a time, using the bypass switch to bring them in and out, set each one up to average 7dB reduction on loud parts. Then start comparing until you find the one (or more) that gets you the tone and smoothness you like.


Company: Universal Audio

Product: Teletronix LA-2A Classic Leveler Plug-in Collection for the UAD-2 Platform.

Price: $299

Pros: An ear candy re-creation of these classics; easy to get great results.

Cons: None.