Discover the Studio Trick Behind Legendary Hit Vocals

Learn how the UAD A-Type Multiband Dynamic Enhancer plug-in gives you the classic sound used by Queen, The Cars, Fleetwood Mac, and more.

For modern music producers, the name “A-Type” conjures images of analog recording studios and ancient equipment used for workhorse tasks like noise reduction and tape transfers to digital. But such associations don’t tell the whole story.

The legacy of the Dolby A-Type noise reduction system* isn’t just about preservation — it is also a story of transformation. What began as a groundbreaking noise reduction circuit in the golden age of magnetic tape quietly shaped the sound of some of the most iconic records of all time as a creative effect.

Now, reimagined as a modern tool for music producers and engineers working in DAWs, the A-Type Multiband Dynamic Enhancer plug-in brings this forgotten “studio secret” back into the spotlight. We sat down with Universal Audio Product Designer Will Shanks to uncover what makes this mythical machine so special.

A pair of vintage noise reduction units with removable CAT-22 A-Type encoding/decoding cartridges. These iconic studio staples were originally used to reduce tape hiss and were later repurposed for their distinctive analog enhancement.

What intrigued you about the A-Type system?

Like everyone else, I thought about it as a tool for noise reduction — namely magnetic tape hiss. I’d heard about engineers hacking A-Type systems for the “air trick” on vocals, but I never pieced it together until I noticed modern plug-in and hardware recreations. Then I became curious and started digging into classic records to hear exactly what A-Type was doing.

It was right there in front of me on classic records from Queen, The Cars, AC/DC, Journey, Def Leppard. It was everywhere. And once you’ve identified it, you can’t un-hear it. It really is an incredible sound, and its pervasiveness might make you think, “well, that’s how vocals are supposed to sound!"

What made the original hardware processor so special?

Its noise reduction capabilities were fantastic. It’s what put Dolby on the map. The unique multiband “compander” process is compressor on encode, expander on decode. You would encode while recording to tape and decode on playback. This gave 8-10dB of transparent noise reduction. It was revolutionary, and is the reason these units were found in studios all over the world. They built units in both the US and UK to keep up with demand.

But the Excite mode is the classic sound you hear on lead vocals, and the "Air" mode is famously used on background vocals. It's incredible how much you can punch up a vocal and make it instantly pop right out in a mix.

Of course these effects can be used on many other sources, but the idea is that you use it on key tracks, or tracks that need to say, “here I am!”

An original 2-channel A301 “S/N Stretcher” card-cage unit. Sliding out the low band cards provides the famous Air trick.

The A-Type system hardware is also used for tape archiving. Can you explain that?

I’ve always thought about the plug-ins we make as a way of preserving history in record making, but this particular plug-in not only provides the preservation of the equipment, but possibly the integrity of many tape recordings. A-Type may end up a cultural safeguard for the analog era! That's actually how this project started, as a need to create a better system for tape archiving.

My UA colleague James Santiago has a room at Sound City. He helps the owner Sandy Skeeter with tape archives. Sound City has a massive tape library and James archives maybe 5 to 10 tapes a week, using Studer A800 and Ampex ATR-102 tape machines.

James was using a Type-A 24-track system built in the ’90s. It was OK, however the channels could get flaky — be it faulty pots, card edges, or other electronics. In addition, there were massive 80-foot snakes with worn out Elko connections between the tape machines and the unit. It just added a lot more risk and stress to the process. Some of the tapes also need to be baked, which means limited playback passes.

That sounds like a serious chore.

It’s a delicate process that I wouldn't have the stomach for! So James looked around for a plug-in that might do what he needed. There was just one plug-in that claimed to do the necessary decode process, but it turned out to be snake oil. So he asked our colleague Dr. Dave Berners if he could make him a decode plug-in. It turned out Dave was already a big fan of that circuit, so Dave created a prototype.

James Santiago at Sound City with Studer A800 and a late-era 24-channel A-Type system for tape archiving.

You can still find the hardware units out there, and there are a few specialists who do A-Type decoding as a part of transferring to digital. But it’s expensive. I’ve heard stories about tape transfers that skip decode and even get remixed without that crucial process. The good news is this plug-in will make it way easier for people to decode even if the transfer happened years ago.

“Once you’ve identified it, you can’t un-hear it. It makes you think, ‘That’s how vocals are supposed to sound!’”

Will Shanks, UA Sr. Product Manager, Plug-Ins

How does UA go about reimagining a complex piece of analog equipment like A-Type in the digital domain?

Dr. Dave started with encode and decode, but started exploring variations on the famed Air mod, of which there are three, as well as different circuit path experiments, ratio mods, and more. The “Cat 22” cartridges which contain the multiband circuit are easy to modify. He experimented on a whole stack of them, which I still have sitting right by me with our A-Type host units. It looks like an old video game console.

It actually wasn’t until we were developing our Sound City Studios plug-in that I started paying attention to any of this. One day a prototype plug-in was loaded up in the control room next to me. Dave was demoing what he called “single band mod” or Crush mode. I heard it from the next room, walked in and fell in love with the sound instantly. I immediately wanted to put it in the Sound City Studios plug-in for crushing room mics. So these two projects just beautifully coincided.

But then it turned out that besides noise reduction, the A-Type units were often used for effects at Sound City. Their house engineer Keith Olsen was famous for it. You can hear it on Fleetwood Mac's 1975 self-titled album for example. Then of course I had to add Excite and Air. James regularly sees old track sheet notes that say “don’t decode” or “air” on one track or another. So historically, it made sense to include A-Type effects in Sound City Studios.

A stack of modified Cat 22 cartridges from the A-Type circuit.

How do you balance creating plug-ins that are authentic to the original vintage hardware, with an eye on the uses for modern music producers?

A lot of this comes from the mind of Dr. Dave. He had already done almost all the experiments on his own and prototyped them. There are actually features excluded from the shipping plug-in that went a little too deep! Like I said earlier, the cartridge style format of the A-Type units makes a fantastic platform for circuit mods and the stack of modified cartridges I have here represent a lot of what went into the plug-in.

That said, there were plenty of direct software experiments as well. My job was to harness all of this great work and expand on it a bit to make it into a user-friendly experience with just the right features and parameter ranges. The UAD A-Type Multiband Dynamic Enhancer plug-in gives creators possibilities beyond what that original multiband circuit is capable of.

The Circuit Mods panel brings modern sound sculpting flexibility to the historic A-Type circuit.

Multiband compression is such a crucial tool in music production. To what lengths did you go to reimagine this important aspect of the A-Type?

We’ve tested and shipped a lot of compressors. But this is the first one that emulates a vintage hardware multiband system. There were some novelties and challenges both in design and testing, but it’s still a compressor and that’s Dave’s personal passion.

In this case we created a linear design, as the clear intention of the A-Type circuit was to be as clean and transparent as possible. So in reality, our plug-in is actually more transparent. But it works fantastic for decoding and with that, everything else naturally falls in line. While we got a really great model, the exciting thing for users is access to those individual bands found in the plugin’s Circuit Mods section.

“After years of overuse, the A-Type trick became cliché. But things come full circle.”

Will Shanks, UA Sr. Product Manager, Plug-Ins

One of the more creative uses of the plug-in is “Crush” mode — it’s quite colorful. I understand it was an experiment that eventually turned into a mode in two UAD plug-ins?

As I said earlier, my gateway into A-Type was listening to the single band Crush mode. I fell in love with it because it was so distinctive for blowing up room microphones. I suppose it’s similar to an 1176 in that it’s also FET-based compression, but there’s something more transparent and pillowy about it that can still be extremely aggressive.

The use of A-Type enhancement became a cliché in production circles after years of overuse. It was used on many records throughout the ’70s, ’80s and into the ’90s as a standard way to mix. It kind of parallels gated reverb in that way. But things do come full circle, right? After we put out the AMS RMX-16 plug-in, I started hearing a whole new wave of “Nonlin” usage — the famous gated reverb program in the ’80s.

So old clichés be damned, I couldn’t leave well enough alone. I thought Crush would be a fantastic way to process audio as a gated reverb.

The A-Type UAD plug-in has five modes that can be used as-is or with additional settings for various creative effects.

Gated mode puts a simple signal gate in front of the Crush compressor. It’s not trying to be an RMX16, but it does do something similar and in some ways better, especially if you are using it with mics that have some distance on them.

What’s your favorite way to use A-Type that might not be obvious to someone just opening the plug-in for the first time? Any tricks or setups that surprised you?

The basic operational principle was a surprise when it was first described to me. A-Type works by raising low level signals while leaving dominant signals alone. This is when the A-Type is operating under encode, or Excite mode. I found the way the four bands and their filters were arranged to be fascinating as well.

A-Type’s block diagram for Encode/Excite.

Perhaps this is a spoiler alert, but by using the parameters found in the Circuit Mods panel, the plug-in can be pushed into many processing specialties: De-essing, noise reduction, expansion, subharmonic enhancement, transient shaping effects, all in vintage style. And you don’t necessarily need to have deep knowledge of multiband principles.

Really, A-Type can be seen as a gateway to its modern dynamic EQ and multiband compression offspring. There are some fantastic presets from artists that will get you there quickly if you want to explore some of these creative uses. There are also presets that will get you excellent matches against the original hardware.

The Cat 43 “Film Processor” auxiliary system “jailbreaks” the A-Type’s four multiband gains.

So you’ve basically taken a black-box noise reduction tool and turned it into a dynamics processor for modern creative uses. Any unintended discoveries you made along the way?

There was a little known add-on product, the Cat 43 Film Processor. It actually did jailbreak the A-Type gains, but with a new circuit design for suppressing environmental noise. It was a funky auxiliary attachment with gain sliders that connected with an extender cartridge. I imagine that back in the day, people were happy to even have that.

In a way, A-Type was the first widely adopted multiband processor. Another fun fact — Dr. Dave bought four A-Type units and a stack of cartridges probably in 2004 or 2005. So I’m sure he was already looking at the design 20 years ago. He’s just been sitting on them hoping to emulate them at some point. So we finally found a reason to bring this iconic processor back into the spotlight. It’s a bit poetic!

The full collection of hardware studied in the making of the A-Type Multiband Dynamic Enhancer.

*The A-Type Multiband Dynamic Enhancer plug-in is not affiliated with, sponsored, nor endorsed by Dolby. The Dolby name, as well as the A-Type model names, are used solely to identify the classic effects emulated by Universal Audio's product.