Reverb: Echo Chambers to Digital Stomp Boxes
Pioneered by Les Paul, reverb has played a key role in recording since the ‘50s.
Reverberation, a/k/a reverb, has possibly been playing a role in music making since humans were cave dwellers. Paleolithic log drummers no doubt realized their rhythms sounded more exciting when performed inside their stone sided homes than out in the open. And the technology remained essentially the same for a few million years, as caves gave way to recital and concert halls.
Reverb as a variable factor in recording came into vogue during the 1950s, thanks in part to the experiments of Les Paul, who used tape delay and multi-tracking to produce the rich echoing guitar sounds of his classic recordings like 1952’s “Bye Bye Blues.” This was also the heyday of the studio echo — or reverb — chamber, which was, essentially, a small man-made cave. Typically echo chambers were hollow enclosures embedded in studio walls or stand-alone metal or concrete tanks. A microphone was placed inside or near the mouth of the enclosures while the band was recording. Vintage tracks from great records made at Memphis’ Sun Studio and Chicago’s Chess Records in the ’50s are perfect examples. Check out Gibson ES-295 legend Scotty Moore's guitar sound on Elvis Presley’s 1955 “Mystery Train” or the lush vocals of Muddy Waters on his 1964 album Folk Singer, which was brilliantly recorded by Leonard Chess.
Reverb began to appear in amplifier designs by Leo Fender in the early ’60s as guitarists began to seek the kind of sounds they could create on studio recordings in live settings. For a time, nearly all American-made amps came with reverb, but as the decades went on reverb has become more of an option than a necessity and many of today’s harmonically rich boutique amps eschew reverb.
In practical and contemporary terms, there are four types of reverb you need to consider when sculpting guitar sounds in the studio or on stage. They are:
• Chamber: Yes, studios with reverb chambers still exist, although a good built-in chamber requires so much real estate that such places are typically older and may lack other contemporary amenities like sound designed walls and ceilings. There are also vintage stand-alone echo tanks still in use and occasionally they can be found on eBay, but most recordists who own reverb chambers never part with them for fear of losing one of the keys to creating a truly vintage sound.
Ad libbing works here, too. A microphone placed in an empty metal 55-gallon drum lifted off the floor can serve as a decent echo chamber, and there’s always the old studio trick of placing an amp, acoustic instrument or a singer in a tiled bathroom.
The problem with an echo or reverb chamber is that the variations in sound it can produce are limited, and high volumes and certain guitar effects tend to destroy the clarity and natural tonal properties chambers.
• Plate: Plate reverb was the practical successor to the echo chamber. When Gibson Country Gentleman namesake Chet Atkins was building RCA Studio B, the famed Nashville recording shop that cut hundreds of hits by the likes of Jim Reeves and Patsy Cline and defined the sound of country music in the ’60s, the room was among the first to use a plate reverb system. Plate reverb uses a transducer, like the one that drives the speaker in your guitar’s amp, to create vibrations in a large plate of sheet metal. A pickup captures those vibrations from the plate and the result is translated into an audio signal. In 1957, this was the absolute cutting edge. Some modern studios have plate reverbs removed from older studios to recreate vintage sounds. As Harold Bradley, the most recorded session guitarist of all time and a vital part of the Studio B legacy, can attest, these reverbs do a splendid job for all types of guitar sounds. The advantage they have over chamber reverbs — besides only taking up a slot on a rack — is that the depth and time of their reverberations can be adjusted by a damping pad suspended inside. Closing the damping pad reduces the size of the plate and therefore the echo it produces.
• Spring: This is where Leo Fender came in. Inspired by the plate reverb, he designed a system enclosed in a small box that uses a transducer at one end of a spring and a pickup in the other. The vibrations are created in the metal spring. This type of reverb was also popular in small, low-budget studios in the ’60s, since it’s much cheaper to make than plate reverb units and requires even less space. Vintage stand-alone reverb boxes can still be found occasionally on eBay and can be easily toted to gigs — using the handle grips on their tops — for use with any amplifier or in-line with a soundboard.
When using a guitar amp with a built-in reverb box it’s important to explore the entire range of the reverberation effect, because the size of the reverb unit and the quality of its construction will affect your sonic options. A good reverb unit will have a wide range of echo, allowing you to add just a bit of a larger room sound to your tone or go for, well, the sound of playing in a cave — or at least a large concert hall. For an exemplary essay in reverb, listen to Peter Green play his legendary “Holy Grail” Gibson Les Paul Standard in his instrumental “The Supernatural” on 1967’s A Hard Road by John Mayall’s Bluesbreakers. His volume plays right into the pocket of his amp’s reverb, creating the kind of searing sustain that would become a trademark of Carlos Santana.
On the other hand, a poorly constructed reverb unit will turn your tone to mush when it’s cranked up. And as a general rule shredding and reverb don’t mix well, since the echoing sound of notes already played will interfere with the clarity of their fast-flying successors.
Another fun quality of the spring reverb is an ability to sound like thunder when it’s set high and the amp gets whacked. That’s the sound of the springs inside colliding. A great example of this effect, as well as a then-cutting-edge use of reverb on unusual guitar licks, can be found in the Stax Records hit “In the Rain,” cut by the Dramatics in 1971.
• Digital: Today digital reverb is the most common variety, appearing in the racks of all contemporary studios and often on guitarist’s pedal boards. Digital reverbs use algorithms to process signals and create their effects, which can range from mimicking an echo chamber to replicating the interior of the Enormo-Dome. Reverb pedals start as low as $50 and go to several hundred dollars, while studio digital reverbs range from $200 to $2,000 and up. The beauty of these units is that they are extremely compact and flexible. And they can simulate and vary timing and frequency response, with high-end units providing a near-limitless amount of variations. It’s thereby possible to use digital reverb to create a more realistic listening experience, regardless of how much analog purists would argue that fact. In the real world, the sound from the stage is always heard first; then the space’s reverberations come next. The space between the two is called “pre-delay,” and good digital studio units can hone in on that with precision.
The advantage of digital reverb pedals for guitarists is that rather then being a slave to the properties of a single built-in reverb, pedals put a wide variety of variations on the effect at the tips of the fingers and toes. That said, at least one manufacturer makes a spring reverb stomp box that’s perfect for emulating slap-back and other vintage reverberant characteristics.
Photo Credit: Gibson Guitars 100 Years of an American Tradition