Basics of Analog Tape Recording | universal sound (2023)

In recent years, the two-inch multitrack tape machine has gone from studio staple to relic rarity. And while many audio veterans are nostalgic for that warm analog sound, few admit they missed the work that went into it.

Today, owning an analog tape machine is comparable to driving a vintage car, with ongoing maintenance, parts shortages, and exotic fuel (analog tape) that is expensive and hard to come by. So while some major studios still offer those classic spinning reels (and the techies that maintain them), the good news for the rest of us is that there are now more convenient ways to get that classic magnetic sound.

Analog recording, of course, predates tape, with everything from wax cylinders to cables used to record a performance. But when American audio engineer Jack Mullin discovered a pair of German tape recorders during World War II, he knew immediately he was on the right track. The format offered two great advantages over the acetate discs of the time: a recording time of more than 30 minutes and the possibility of editing the recordings. It was the first time that audio could be manipulated.

Mullin brought both tape recorders home after the war and showed them to Bing Crosby at MGM Studios in 1947. Crosby immediately saw the potential of pre-recording his radio shows and invested a small fortune of $50,000 in a local electronics company called Ampex to develop a production model.

Ampex and Mullen soon followed with turnkey recorders. An early Ampex Model 200 recorder was given to guitarist Les Paul, who took the concept of audio manipulation to the next level. Having experimented with overdub recording to disk, Paul quickly saw the potential of adding more channels and additional record and playback heads and came to Ampex with the idea for the first multitrack tape recorders.

The format evolved from two tracks to three and four, and although Ampex built some of the first eight track machines in the late 1950s, most commercially available machines were limited to four tracks until 1966, when engineers at Ampex Abbey Road sound Geoff Emerick and Ken Townshend began during the recording of Sgt. Pepper's Lonely Hearts Club Band.

Ampex responded to the demand the following year by introducing the revolutionary MM-1000, which recorded eight tracks on 1-inch tape. Scully also introduced a 12-track 1-inch design that year, but this was quickly eclipsed by a 2-inch 16-track tape version of the MM-1000. MCI followed in 1968 with 24 tracks on 2-inch tape, and the 24-track 2-inch format became the most common format in professional recording studios for most of the 1970s and 1980s.

With the proliferation of home and project studios and digital technology in the late 1980s and 1990s, other tape formats emerged, including various multitrack reel and cassette configurations, as well as various digital tape formats. But for this article, we're going to focus primarily on analog multitrack tape, the most sonically revered recording medium of all time.

Simply put, magnetic tape is a thin layer of Mylar or similar material coated with iron oxide. The tape machine head exerts a charge on the oxide which polarizes the oxide particles and effectively "captures" the signal. It's a process that produces some interesting by-products, many of which directly affect the sound of the recording.

Perhaps the most cited characteristic of analog recording is its "warmth". The warmth of the band adds a bit of color to the sound, mainly softening the attacks of musical notes and thickening the low-frequency range. Recording at slightly warm levels on analog tape can also produce good distortion that works well with certain types of music such as rock, soul, and blues.

As multitrack recording evolved, a number of different manufacturers emerged. By the early 1980s, Ampex was no longer the dominant multitrack manufacturer, facing stiff competition from MCI, Studer, 3M, and Otari. While a handful of smaller manufacturers including Stephens, Aces and a few others also joined the fray, Ampex, Studer, 3M, MCI (later owned by Sony) and Otari became the dominant brands. The various models from these manufacturers were loved (or despised) for their mechanical properties and distinctive sound. In the past, a recording studio's multitrack recorder was considered as essential to your sound as your acoustics, console, or microphone collection.

A variety of factors go into the distinctive sound of any machine, starting with tape heads, amplifiers, and other electronic components. In addition, other factors influence the sound of an analog recording, some of which are unique to each machine. Variations in device speed stability (wow and wobble), orientation and angle of tape heads, condition of tape heads (cleanliness, magnetization, etc.), tape tension and other physical factors are just some of the things that can affect audio. of a recording.

Factors beyond the device itself can affect the particular sound of an analog recording, including the brand of tape used. In the heyday of analog technology, every major brand of tape had its supporters and critics. Ampex Tape was one of the leading brands, with its 456 formula being the best known. Other popular brands were AGFA and 3M. Each band formulation lent its own subtle tone to a recording, and each unit had to be recalibrated with each brand change. Some studies stuck to one brand of tape, but it was not uncommon for discrepancies to occur even in different batches of the same brand of tape.

The speed of the treadmill is another important factor. Higher tape speeds tend to provide cleaner sound quality because the signal is spread over a larger area and the signal-to-noise ratio increases. The most commonly used speeds with 2-inch tape are 15 and 30 IPS (inches per second). While 30 IPS provides better overall sound quality, most professionals agree that lower frequencies sound better at 15 IPS. Today, when tape is most commonly used for its sound effect, slower speeds prevail.

While owning a vintage 2-inch Studer or Ampex tape machine certainly deserves bragging rights, in today's DAW-oriented world, it's a given that fewer of us would choose to record on analog tape—even if we did, we might have space considerations, cost, and a shortage of tapes and replacements is just the beginning.

The fact is, in a world where time really is money, destructive tape editing can be a slow and tedious process. And the medium itself is no longer economical. A single roll of 2-inch tape averages about $200. At 15 IPS, this tape will have about 30 minutes of recording time for 24 tracks (half that at 30 IPS). Compare that to a 2TB hard drive, currently selling for under $100, that can store many hours of multitrack audio, and you can see why using tape for every project isn't the option for most of us.

Fortunately, there are a number of great-sounding plug-in processors for your DAW that can bring some of that "glue" and analog tape warmth to your tracks. For example, Universal Audio is very popularStuder A800 multitrack recorderis an incredibly faithful emulation of the original machine's sound, painstakingly developed over a year with input from the original manufacturer. In fact, the sonic differences between the A800 plug-in and the original A800 hardware are so small that many of the world's top engineers choose to use the plug-in in their daily work.

Besides the obvious convenience factor, one of the biggest advantages of tape emulation plugins is their flexibility. You can choose to process only specific tracks rather than the entire mix, giving drum and bass tracks, for example, the warmth, deep punch, and cohesiveness of tape without adding tape color to guitars and vocals. . Or you can add just a touch of tape compression to the mix without over-cluttering things like a real two-track machine.

However you implement it, analog tape sound can be a great addition to your digital mix. Try a UAD tape emulation plugin like the Ampex ATR-102 to add some cohesive "glue" to the mix bus. Or you may find the Studer A800 just right for adding some low-key warmth and bass punch to your mix. Record Liveson.