A close look at acoustic design reveals artfully engineered contours that strike an ideal balance between structural strength and musical responsiveness.
As acoustic guitar players and makers, we use the term "flattop guitar" so often it may come as a surprise when careful investigation reveals the top and back of a guitar to be anything but flat. While an archtop guitar's dramatically sculpted top and back contours are obvious at first glance, signaling cello-like inspiration and construction, the subtle contours of our favorite flattops are equally critical for the structure and sound we love.
To better understand how this gracefully curved structure works, consider the practicalities of how a guitar top is constructed. From a board, a very thin sheet of wood is cut. Typically, two or more pieces are joined together edge-to-edge in order to provide the most predictably uniform wood grains across the width of the guitar. This top usually has what's known as quartersawn grain orientation for maximum strength and consistency, with the growth rings of the wood perpendicular to the guitar's face, as if the hard grain lines were miniature structural beams.
Braces are glued to the underside of the top in any number of different arrangements. The purpose of these braces is to guide the vibration of the top in a way that makes a pleasing musical sound, while imparting enough strength to the top to avoid physical distortion or outright fracturing when supporting the tension of the strings.
One challenge a guitar maker faces is to build the top with very light weight, so it can respond easily to string vibration, yet enough strength and stability to withstand the immense tension. When a flat sheet of material is bent into a curve, even a subtle curve, its strength is increased significantly. Imagine a sheet of paper. It's very thin and incredibly flexible. When held in a curved shape, it becomes far stronger perpendicular to the axis of the bend.
When a flat sheet of material is bent into a curve, even a subtle curve, its strength is increased significantly.
In a more extreme example, if the paper is rolled into a tube, it becomes exponentially stronger, all without adding any additional mass. This same principle is applied to a guitar top. Most commonly, instead of a mere cylinder shape, where the top is arched in a single direction, the top is gently coaxed into a spherical shape, increasing its strength in every direction. This spherical shape is formed and held in place by cutting a corresponding curve into the braces and sides of the guitar—which are far less flexible than the thin wood of the top itself—and gluing the entire structure together to anchor this shape in place.
Unlike the top, the grain orientation of the braces glued to the top prevents them from following the shrinking or swelling in dry or humid conditions. As a result, the top or back will slowly sink, eventually becoming flat, or even slightly concave, in dry weather. The subtle built-in arch of a top or back allows the wood to have room to shrink before it cracks. We could think of this as building in some slack to prevent damage. In humid conditions, the top and back will swell, rising up into a higher arch as the wood grows in size. While this will temporarily raise the strings higher from the fretboard and make the guitar harder to play, no further damage is imminent.
The practices of arching a top and back are practical habits of instrument makers that stretch back hundreds of years. Each maker has its own approach to this subtle art and uses this as an ingredient in voicing the sound of instruments. Regardless of the exact amount and relationship of the arches, which vary by the maker's design and are further influenced by the weather and conditions of the day, it seems our guitars remain a curiously beautiful balance of carefully thought-out physics and artful practicalities.
With three voices, tap tempo, and six presets, EQD’s newest echo is an affordable, approachable master of utility.
A highly desirable combination of features and quality at a very fair price. Nice distinctions among delay voices. Controls are clear, easy to use, and can be effectively manipulated on the fly.
Analog voices may lack complexity to some ears.
$149
EarthQuaker Silos
earthquakerdevices.com
There is something satisfying, even comforting, about encountering a product of any kind that is greater than the sum of its parts—things that embody a convergence of good design decisions, solid engineering, and empathy for users that considers their budgets and real-world needs. You feel some of that spirit inEarthQuaker’s new Silos digital delay. It’s easy to use, its tone variations are practical and can provoke very different creative reactions, and at $149 it’s very inexpensive, particularly when you consider its utility.
Silos features six presets, tap tempo, one full second of delay time, and three voices—two of which are styled after bucket-brigade and tape-delay sounds. In the $150 price category, it’s not unusual for a digital delay to leave some number of those functions out. And spending the same money on a true-analog alternative usually means warm, enveloping sounds but limited functionality and delay time. Silos, improbably perhaps, offers a very elegant solution to this can’t-have-it-all dilemma in a U.S.-made effect.
A More Complete Cobbling Together
Silos’ utility is bolstered by a very unintimidating control set, which is streamlined and approachable. Three of those controls are dedicated to the same mix, time, and repeats controls you see on any delay. But saving a preset to one of the six spots on the rotary preset dial is as easy as holding the green/red illuminated button just below the mix and preset knobs. And you certainly won’t get lost in the weeds if you move to the 3-position toggle, which switches between a clear “digital” voice, darker “analog” voice, and a “tape” voice which is darker still.
“The three voices offer discernibly different response to gain devices.”
One might suspect that a tone control for the repeats offers similar functionality as the voice toggle switch. But while it’s true that the most obvious audible differences between digital, BBD, and tape delays are apparent in the relative fidelity and darkness of their echoes, the Silos’ three voices behave differently in ways that are more complex than lighter or duskier tonality. For instance, the digital voice will never exhibit runaway oscillation, even at maximum mix and repeat settings. Instead, repeats fade out after about six seconds (at the fastest time settings) or create sleepy layers of slow-decaying repeats that enhance detail in complex, sprawling, loop-like melodic phrases. The analog voice and tape voice, on the other hand, will happily feed back to psychotic extremes. Both also offer satisfying sensitivity to real-time, on-the-fly adjustments. For example, I was tickled with how I could generate Apocalypse Now helicopter-chop effects and fade them in and out of prominence as if they were approaching or receding in proximity—an effect made easier still if you assign an expression pedal to the mix control. This kind of interactivity is what makes analog machines like the Echoplex, Space Echo, and Memory Man transcend mere delay status, and the sensitivity and just-right resistance make the process of manipulating repeats endlessly engaging.
Doesn't Flinch at Filth
EarthQuaker makes a point of highlighting the Silos’ affinity for dirty and distorted sounds. I did not notice that it behaved light-years better than other delays in this regard. But the three voices most definitely offer discernibly different responses to gain devices. The super-clear first repeat in the digital mode lends clarity and melodic focus, even to hectic, unpredictable, fractured fuzzes. The analog voice, which EQD says is inspired by the tone makeup of a 1980s-vintage, Japan-made KMD bucket brigade echo, handles fuzz forgivingly inasmuch as its repeats fade warmly and evenly, but the strong midrange also keeps many overtones present as the echoes fade. The tape voice, which uses aMaestro Echoplex as its sonic inspiration, is distinctly dirtier and creates more nebulous undercurrents in the repeats. If you want to retain clarity in more melodic settings, it will create a warm glow around repeats at conservative levels. Push it, and it will summon thick, sometimes droning haze that makes a great backdrop for slower, simpler, and hooky psychedelic riffs.
In clean applications, this decay and tone profile lend the tape setting a spooky, foggy aura that suggests the cold vastness of outer space. The analog voice often displays an authentic BBD clickiness in clean repeats that’s sweet for underscoring rhythmic patterns, while the digital voice’s pronounced regularity adds a clockwork quality that supports more up-tempo, driving, electronic rhythms.
The Verdict
Silos’ combination of features seems like a very obvious and appealing one. But bringing it all together at just less than 150 bucks represents a smart, adept threading of the cost/feature needle.
EarthQuaker Devices Silos Multi-generational Time Reflection Delay Pedal
Silos Delay PedalPositive Grid unveils Spark EDGE, a multi-channel smart amp & PA engineered for musicians demanding portability, versatility, and pro-level sound.
Positive Grid unveils Spark EDGE, a multi-channel smart amp & PA engineered for musicians demanding portability, versatility, and pro-level sound. Designed for everyone from singer-songwriters and buskers to acoustic duos and electric players, Spark EDGE packs 65 watts of studio-quality sound, built-in effects, and a looper into a lightweight, compact design. Capable of serving as an amp, PA, or personal monitor, Spark EDGE offers flexible connectivity for electric and acoustic guitars, bass, vocals, keyboards, and more. With optional battery power (sold separately), Spark EDGE delivers the freedom to perform anytime, anywhere.
Pro-Level Sound with Advanced Audio
Powered by Sonic IQ Computational Audio, Spark EDGE enhances every note with precision. Its tech-driven system features a dedicated computational audio chip that refines dynamic range, boosts vocal clarity, and deepens bass. The result? Precise, immersive sound in any setting. Complemented by an advanced speaker design—featuring a woofer, tweeter, and reflex ports—Spark EDGE delivers rich, full-bodied sound that brings any performance to life.
Seamless Multi-Instrument Connectivity
Featuring four versatile channels, Spark EDGE offers seamless connectivity for multiple instruments:
- Channel 1: Equipped with 36 amp models and 50 effects for electric guitars, acoustic guitars, bass, and vocals.
- Channel 2: Tailored with dedicated amp models and effects for vocals, bass, and acoustic guitars.
- Channels 3/4: Stereo input channels designed for keyboards, drum machines, and other instruments.
All the Gear in One App
The Spark App transforms Spark EDGE into a performance powerhouse:
- 36 Amps: Instant access to guitar, bass, and acoustic amp models
- 50 Effects: A comprehensive selection of built-in effects for any instrument
- Creative Groove Looper: Layer, loop, and experiment with over 100 drum patterns
- Spark AI: Automatically generate the ideal tone with AI-powered suggestions
- Smart Jam: Create dynamic backing tracks that adapt to any playing style
- Auto Chords: Real-time chord display for millions of songs
- 100,000+ Tones: A vast library of downloadable tones, created by musicians worldwide
Ready for the Road
Lightweight yet rugged, Spark EDGE is built to go anywhere. Featuring an ergonomic handle for easy carrying and a durable design that withstands the rigors of travel, Spark EDGE offers two listening angles—upright or tilted. In addition, an optional rechargeable battery (sold separately) offers up to 10 hours of playing time per charge.
Limited Edition Grilles
Limited-edition grilles (sold separately) allow for personalization, with bold designs like Sunburst and On the Edge offering a distinct, eye-catching look before the first note is even played.
Essential Extras
- Bluetooth® Streaming: Stream music directly through the amp and blend tracks with live performances using onboard volume control
- WiFi: Over-the-air firmware updates ensure seamless improvements, with no computer required
- Send stereo outs to the PA and use Spark EDGE as a monitor while maintaining tone control
- Compatible with Spark accessories including Spark Control X, Spark CAB, Spark LINK and more
Handmade in Japan, this bass features a bolt-on hard maple neck, alder body, VolaJS5-N neck and Vola JS5-B bridge pickups, and a Vola ATR-I Active 3-band EQ. Experience top-quality craftsmanship and tonal potential with the ZVA 5 Bass.
The tried-and-true ZVA bass is back, this time with additional range! The all-new 5-string version maintains its most prominent features while providing players with an expanded scope of tonal potential. Its bolt-on hard maple neck is equipped with 21 frets, a rosewood fingerboard, a 34.5” scale, and a Duracon nut for optimal performance. The modern C-shaped neck allows for easy access to the entire fretboard while maintaining perfect comfort. The body is made of alder, offering a balanced playing experience. From a hardware standpoint, the nickel components were manufactured by Gotoh, including the machine heads and a string-through bridge setup. The bass is equipped with VolaJS5-N neck and Vola JS5-B bridge pickups, coupled with a Vola ATR-I Active 3-band EQ and a handy mini switch for seamless transition between passive and active modes. Overall, the ZVA 5-string carries on its predecessor’s legacy with extended range and accessibility for every type of bassist.
Features Include
- Country of Origin: Handmade in Japan
- Construction: Bolt-on neck
- Body: Alder
- Neck: Maple/Rosewood, Vola Modern C shape (bass) 1F(21.5mm)/ 12F(24mm)
- Fingerboard: Maple, 9.5" Radius
- Inlays: Classic dot inlay
- Nut: 47.6mm Duracon nut with Zero Fret
- Frets/ Scale: 21 Frets/ 34.5"
- Pickups: Vola JS5 neck, Vola JS5 Bridge
- Electronics: 1 Volume, 1 Balance, Vola ATR-I Active 3band EQ, 1mini switch(passive/active)
- Hardware: Gotoh 303 SJ 5 Bass bridge w/String thru the body, Gotoh 404SJ-5(4:1) Tuners
- Strings: Daddario EXL-170-5SL 45-65-80-100-130 Super long
- Misc: 4mm Allen key for truss rod adjustment
- Country of Origin: Handmade in Japan
- Case: Vola Custom Series bass Gig bag
The Vola ZVA 5Bass is the culmination of Vola’s dedication to designing top-quality instruments for demanding players, without sacrificing the beauty that invites a closer look. Visit their website or your local Vola dealer for a closer look at the Vola ZVA 5 Bass. The Vola OZ Supernova has a street price of$1,189 USD. Vola Guitars now sells direct!
For more information, please visit volaguitars.com.
Introducing: The All-New ZVA 5 Bass - YouTube
If you’re new to Priest’s music or are trying to find your own starting point, we’ve got some great tips for guitar jammers. And if you’re a hardcore fan, maybe you’ve got some tips you can share for our next steps.
In this episode, we’re celebrating the thrill of guitarmony, sick riffs, and driving 8th-note rhythms by talking about Judas Priest. Before getting ready for this episode, neither of your esteemed hosts had ever delved into the Priest discography beyond the rock-radio hits and Beavis and Butthead—though we’d both spent our time with Heavy Metal Parking Lot. Since so many of the GOATs hold the band in the highest of regard, we knew that K.K. Downing and Glenn Tipton belonged on this list, so we embarked on a journey to find out why.
After hours of listening and watching, we’re happy to report that we get it. From their debut, 1974’s Rocka Rolla, through 1980’s British Steel, deep into the ’80s-production era with 1986’s Turbo, and through the speed-metal bravado of 1990’s Painkiller, plus live videos and records—the super-loud US Festival performance and the crushing Unleashed in the East record—we found a lot that we love.