This month I thought I’d give you amptechs a tip that is not widely known at all: it is not only possible, but easy...
This month I thought I’d give you amptechs a tip that is not widely known at all: it is not only possible, but easy, to test a transformer for internal shorts that are not otherwise detectable. Before you go and replace an expensive transformer, you need to try this.
Any of us who have worked on transformers are familiar with how you test for opens on the windings and shorts from winding to winding. You get out your ohm-meter and start measuring resistance. Opens where there is supposed to be resistance or resistance where there is supposed to be an open are dead giveaways. But what if there is one turn shorted down deep in the middle of a winding? The resistance testing will never pick that up – it’s not a big enough change in resistance.
Here’s how to tell if there’s an internal short. First, as always, unplug the amp for safety. If we disconnect all the windings of a transformer and then apply a DC voltage to only one winding, the iron core thinks it’s just an inductor. The voltage causes a current to flow in the inductor.
When you open the circuit, the magnetic field stored in the iron core creates a voltage on the winding to try to keep the current flowing – well-known inductor kickback.
All of the windings on the transformer are also magnetically coupled to the iron, and a proportional voltage appears on every one of them. If we connect a common neon lamp like the venerable NE-2 bulb to any winding and load up any winding with DC, when we open the DC loop, the voltage on all windings will increase until something conducts current. If all of the windings are open (as they should be), the NE-2 lamp will break over and flash when the voltage across it hits 75-90V.
But if there is a shorted turn inside the transformer, the iron’s stored magnetism will be entirely spent on trying to make the current keep flowing in that turn of wire. The neon light will not flash.
A simple setup for this is shown in the illustration: a DC supply, a neon bulb plus a resistor (to keep from burning out the neon) and some wire clips. I use a 6V lantern battery, but any DC supply will work as long as it will not be damaged by being connected to a low-resistance transformer winding. A current-limited bench supply works fine. I think a 9V battery or a D cell might work too, but I haven’t tried them.
First, make sure there are no loads on any winding. Then clip the neon and resistor across any winding. Touch your DC source to any winding, and then open it. Watch the lamp. If it flashes, there is no internal or external short. If it does not flash, there is a short. It’s that easy.
Keep in mind there are a few sneaky things that can invalidate your test. If there is a load on any winding, those loads will eat the inductive kickback and the neon will not light up. You’ll think you have a bad transformer but you might not. If the transformer is a power transformer, watch out for connections to filament windings or solidstate rectifiers. If it’s an output transformer, make sure the speaker is not connected and there is no minimum load resistor on the output jack or diode from plate to ground, as is found in some amps.
I don’t know who first thought this up, but I mentally thank them each time I have to test a transformer. Go ahead – try it!
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We’ve compiled this year’s best deals in the 2022 Holiday Gift Guide presented by Guitar Center.
Designed for utmost comfort and performance, the Vertigo Ultra Bass is Mono’s answer to those who seek the ultimate gigging experience.
Complete with a range of game-changing design features, such as the patent-pending attachable FREERIDE Wheel System, premium water-resistant and reflective materials, shockproof shell structure and improved ergonomic features, the Vertigo Ultra Bass takes gear protection to the next level.
The Vertigo Ultra Bass features:
- Patent-pending FREERIDE Wheel System that allows for wheels to be attached on the case in no time, giving you the option to travel with it seamlessly
- Upgraded materials, including a water-resistant 1680D Ballistic Nylon outer shell, plush inner lining and new reflective trim for maximum backstage and night visibility
- Enhanced protection with a shockproof shell structure and heavy-duty water-resistant YKK zippers for protection from the elements
- Improved ergonomics and functionality including added back support and load-lifting detachable shoulder straps with side release buckles
- Flexible storage options with added space for touring essentials
The Generation Collection of acoustic guitars features the exclusive Gibson Player Port designed to offer a unique and immersive sonic experience.
The G-Bird, the newest addition to the Generation Collection--represents the glorious legacy of the Gibson Hummingbird colliding with modern sonic enhancement through the Gibson Player Port to add a new dimension to the G-Bird sound. The Gibson Player Port allows players to hear more of themselves as the audience hears it. With a tone that is crisp and resonant, all of the Gibson Generation Collection acoustics are designed to be comfortable to hold and play for long periods of time. All Generation Collection guitars feature the Gibson Player Port, slim, lightweight bodies, a flatter fingerboard radius, Walnut back and sides, Sitka spruce tops, and a stunning Natural finish. Additionally, the new G-Bird, and the G-200 and G-Writer are equipped with LR Baggs™ Element Bronze pickup systems which amplify deep bass and crystal-clear highs.
The G-Bird represents the glorious legacy of the Gibson Hummingbird with modern sonic enhancement through the Gibson Player Port adding a new dimension to the G-Bird’s sound. The G-Bird features a stunning solid Sitka spruce top and solid walnut back and sides for the ultimate in crisp, resonant tone. This square-shoulder dreadnought delivers all the rich low end and well-balanced mids and highs the original Hummingbird is famous for. The TUSQ nut and saddle, along with chrome Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning. The utile neck, with its easy-playing Advanced Response neck profile, is so comfortable you won’t want to put it down. The G-Bird also comes equipped with an LR Baggs Element Bronze pickup system, so it will always sound as good to your audience as it does to you. The G-Bird also comes equipped with an LR Baggs™ Element Bronze pickup system, so it will always sound as good to your audience as it does to you. The G-Bird is available in Natural finish. A gig bag is included.
Modeled after Gibson’s pioneering small-body parlor acoustic guitars from the 1930’s, the G-00 is a top choice for blues and fingerstyle guitar performances. Despite its more compact size, the G-00 achieves a full, balanced sound. The G-00 fills any room with rich tones-which players can hear like never before, with the exclusive Gibson Player Port. Like all models in the Gibson Generation Collection, the G-00 is handcrafted in Bozeman, Montana, by the same highly--skilled craftspeople who make all Gibson acoustic guitars. The G-00 features a beautiful solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The slightly thinner G-00 parlor-sized body is exceptionally comfortable to hold and play. The TUSQ nut and saddle along with the Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-00 is available in Natural finish. A gig bag is included.
The G-45, a round-shouldered jumbo, adds the Gibson Player Port to its famous “Workhorse” J-45 style body, which is Gibson’s best-selling acoustic guitar of all time. On the G-45, players can now hear more clearly than ever how this beloved guitar responds to every style and technique of playing. Powerful one moment and soft the next, the G-45 delivers all sounds with incredible dynamic range in an elegant, medium body size. The G-45 is part of the Gibson Generation Collection and like all models in this collection, it is handcrafted in Bozeman, MT, by the same highly skilled craftspeople who make all Gibson acoustics. It features a solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The G-45 features a slightly thinner round shoulder body is exceptionally comfortable to hold and play. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners deliver solid tuning stability, so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-45 is available in Natural finish. A gig bag is included.
Gibson’s impressive range of square-shouldered guitars have become an expressive standard for rock, pop, folk, and country artists. The G-Writer is known for its wide range of sounds, from gutsy and loud, to soft and sweet; they are superb for all styles and shine, whether strumming chords or fingering intricate solos. The G-Writer comes ready for the stage or studio with an LR Baggs Element Bronze pickup system and the ear-opening Gibson Player Port. The G-Writer is part of the Gibson Generation Collection and like all models in this collection, it is handcrafted in Bozeman, MT, by the same highly skilled craftspeople who make all Gibson acoustics. It features a solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The G-Writer features a slightly thinner cutaway body, is more comfortable to play and provides effortless access to the upper frets. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners deliver solid tuning stability, so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-Writer is available in Natural finish. A gig bag is also included.
Gibson built its first “Super Jumbo” SJ-200 as a custom order for country and western singer and film star Ray Whitley, who desired a big, loud, and deep flat-top over which to croon. The SJ-200 quickly became a staple of cowboy singers and horseback troubadours, and then country music, 60’s folk stars, and onto every acoustic guitar genre that has followed. Ray would be proud to hear the booming sound from the Gibson Player Port on the new G-200, which comes ready for the stage or studio with a LR Baggs Element Bronze pickup system. Like all models in the Gibson Generation Collection, the G-200 is handcrafted in Bozeman, MT, by the same highly--skilled craftspeople who make all Gibson acoustics. The G-200 features a beautiful solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The slightly thinner G-200 cutaway jumbo body is exceptionally comfortable to hold and provides excellent access to the upper frets. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-200 is available in Natural finish. A gig bag is also included.
G-Bird | Generation Collection
For more information, please visit gibson.com.
Looking for a compact, “noiseless” way to plug in and play guitar? Check out the brand-new Gibson Digital Amp, available only in the Gibson App.
The new Gibson App simplifies the learning process and brings guitar playing to life for the current and next generation of guitarists in a modern, comprehensive, and intuitive way. The Gibson App is the place to take your guitar playing to the next level. New to the Gibson App is the Gibson Digital Amp, the ultimate starting amplifier for beginners and a flexible amp on-the-go for intermediate players and pros to get their sound anywhere. The Gibson Digital Amp is an accessible amplifier for both acoustic and electric guitars, and is currently available for Apple/iOS users--an Android version will debut next year.
Use the Gibson Digital Amp’s jamming guide to get started and transform your sound with built-in effects and pedals, jam to backing tracks, or use it in lessons and songs. The Gibson Digital Amp only requires your phone, and wired headphones for the best playing experience, no cables are needed. The amp features 3 acoustic mic presets, 4 electric amp presets, and 6 effects pedals.
The Gibson Digital Amp is the ultimate starting amplifier for beginners and a flexible amp on-the-go for intermediates and pros.
The Gibson App uses a unique two-way, interactive platform to teach guitar students how to do everything from playing their first note to shredding loads of songs. The Gibson App features interactive lessons with thousands of lessons and songs. Learn the songs step-by-step with video tutorials from superstar artists and pro guitarists in the “Gibson App Guide.” The Gibson App also includes the new Digital Amp, a built-in tuner, a metronome, Gibson TV, and new songs are added every week. New Gibson App Guides are added regularly and include Tommy “Spaceman” Thayer’s favorite iconic KISS guitar solos, Richie Faulkner’s (Judas Priest) “Guide to Metal,” Jared James Nichols’ “Guide to Blues,” CELISSE’s “Guide to Songwriting,” and more.
The Gibson App uses “audio augmented reality” to provide dynamic feedback to students as they learn and play. As you pluck a note or strum a chord, the Gibson App listens to your guitar and gives you real-time feedback on your playing. It also gives students a more contextual learning experience: Instead of learning chords and scales in a vacuum, you’re able to practice on a scrolling tablature that lets you hear how you sound with the backing of a virtual band. That means you can load up “Hurt” by Johnny Cash, “Brown Eyed Girl” by Van Morrison, “American Girl" by Tom Petty, “Nothing Else Matters” by Metallica, “Where is My Mind" by Pixies, “Country Roads” by John Denver, “I Hate Myself For Loving You" by Joan Jett, “Heaven” by Kane Brown, “Shape Of You” by Ed Sheeran, “Killer Queen” by Queen,“ Sweet Child O’ Mine,” by Guns ‘N Roses, “Run to the Hills” by Iron Maiden, “Roxanne” by The Police, and “Don’t Stop Believin’” by Journey, “Smells Like Teen Spirit” and “The Man Who Sold the World” by Nirvana, “Are You Gonna Go My Way” by Lenny Kravitz, and “Don't Look Back In Anger” by Oasis and hundreds more songs in a wide range of genres, to see how your play matches up with such seminal tracks.
As you’re playing, the Gibson App gives you feedback on timing and tone, ensuring that students are getting active input on how their play is developing. The Gibson App appeals to players of all levels, it’s not just for beginners looking to learn a few chords; the app can assist seasoned guitarists who are working their way through difficult riffs, want to learn their favorite songs, or polish their advanced techniques.
Players can also challenge themselves by speeding up or slowing the tabs. Like having a full-time guitar teacher, the Gibson App keeps track of all your progress and adjusts lesson plans accordingly. The Gibson App released a “backing track mode” which supports both lesson and song playback without headphones, so users can self-select what works best for their current environment. And that’s not all: the Gibson App also packs in a fully-featured digital tuner for guitar first-timers, there’s even a detailed lesson on how to tune your instrument, a multi-function metronome, players can connect to free one-on-one consultations with Gibson’s Virtual Guitar Tech team, and to direct links to the Gibson, Epiphone, and Kramer online stores for easy shopping for guitars, gear, apparel, and accessories.
Learn Guitar With The Gibson App
The Gibson App is more than a pocket-sized guitar teacher, it’s loaded with an archive of exclusive content and original programming from its premium and accessible award-winning online network, Gibson TV, featuring music icons telling their best guitar stories, with more episodes and installments added regularly. Users can watch Black Sabbath’s Tony Iommi share insights and tales from his decades-long career on the series “Icons,” dive into Joe Bonamassa’s assortment of legendary Les Paul guitars on “The Collection,” or see how Gibson’s iconic instruments are made in their Nashville factory from body to binding on “The Process.” There’s even a series called “The Scene” that focuses on backstage stories from hallowed music venues from coast to coast like The Troubadour and Grand Ole Opry.
The Gibson App free version features a few lessons a day; the premium version of the Gibson App offers full access and a 14-day free trial, then costs $19.99/£16.49 monthly or $119.99/£98.99 yearly.
For more information, please visit gibson.com.