All 9V blocks are not created equal. Here's what to look for to avoid hiss, hum, and crackle.
(Originally published April 22, 2020)
At the dawn of the guitar-effects age, powering pedals was relatively simple. If an effects pedal didn't take a standard 9V battery like your AM transistor radio, it plugged into the wall like your avocado-green toaster. Forever dissatisfied, guitar players eventually grew weary of changing batteries, and plugging stuff into the wall was kind of a drag, too.
As the industry was looking to eliminate its batteries and Edison plugs, the effects purveyor Boss went a long way to standardizing pedal power by putting a 2.1 mm coaxial power jack on all their pedals, and while their market dominance made the 1/8" jack on certain Ibanez and Pro Co pedals outliers, even they couldn't stick to one standard for long as they transitioned from 12V ACA spec pedals to 9V PSA spec pedals.
Once that growing pain subsided, it was relatively peaceful on the pedal-powering front for many years, and the standardization allowed companies to produce power supplies that let players power all their pedals simultaneously and without harming a single battery. Some supplies had a single output with daisy chains to fan out power to multiple pedals. Some were isolated, offering an individual power port for each pedal and eliminating daisy-chaining all pedals in a parallel fashion. Isolated supplies were a huge development in pedal-powering history, so let's dig in there before wading further into the power morass of today.
In this context, isolated power supplies are those supplies that are essentially a series of separate power sources in one enclosure. Each supply stands on its own with no direct connection to any of the other supplies, and, as such, the effects they power have no direct connection to one another through their respective power ports.
There are several reasons power supply isolation can be anything from favorable to crucial. First, some pedals have a positive-ground scheme, where the audio ground of the effect is connected to the positive terminal of the battery, usually due to the type of transistors used in the pedal's circuit.
Isolated power supplies are those supplies that are essentially a series of separate power sources in one enclosure.
While fuzz pedals are often set up this way, most pedals have a more conventional negative-ground scheme. If you parallel connect the power of a positive-ground pedal to a negative-ground pedal, and then connect their audio grounds together with a patch cable, you'll cause a power supply short, and neither pedal will get power. The power source will complain, too! Isolated supplies mimic a battery as each device gets its very own power source to use independently of any other device.
Crosstalk is another reason for isolation. Some pedals don't play well with others when powered in parallel. Like so many playground bullies, tremolos and vibratos can tick and pop while overdrives and DSP effects with switch-mode supplies and high-speed processors can whine, and they can torment their boardmates with their glitches. These deficiencies might not bother the offending pedal, but the trash they put on their power supply ports gets leaked to other connected devices that may not be able to reject the noise quite as well. Isolation breaks the link and prevents such crosstalk.
The last reason for isolation we'll list here is ground loops. In general, for guitar rigs, it's best practice to have just one ground path. Typically, that one path should be the ground connections of all of your patch cables extending in a line from guitar's output to amp's input. Daisy-chaining power creates other ground paths that make closed loops from one section of your signal flow to another. These ground loops can make your rig more susceptible to hum pickup in the presence of electro-magnetic fields. If you have daisy-chained pedals both in front of an amp and in its FX loop, and dozens of feet of cable between them, the associated ground loops can become very large and produce a great deal of noise. Using an isolated supply disconnects the links that make the loop, and the induced hum can no longer be sustained.
With isolation addressed, power supplies remained relatively unchanged for many years. Then, digital-signal processing became cost-feasible for common use in guitar-pedal effects. We'll dig further into their high-current demands and how they've complicated the power supply marketplace in my next column.
A Canadian guitarist has his dream G&L made to match his Harley.
Name: Dan Kyle
Location: Maple Ridge, British Columbia, Canada
Guitar: Custom Legacy HB
I’m a big Alice in Chains fan. I started checking out what Jerry Cantrell was playing and discovered the G&L Rampage, and it’s been no looking back. I’ve owned tribute Rampages, S-500s, a Legacy Special, and the olive green HB with Dual-Rails and a Floyd. They’re all fantastic instruments, made by the master, Leo Fender, in his prime. I loved them all so I decided to have one made.
This guitar is a Legacy HB, custom-made to match my 2004 Harley FXDP. I contacted Music Store Live and they did the rest. I wanted a Seymour Duncan JB for the heaviness, but wanted to have the G&L CLF-100 single-coils as well, because they’re excellent sounding. The neck is an extra-wide C-shape that’s 1 3/4" at the nut for my ham hands. It’s perfect! It has an ebony fretboard, a Graph Tech nut, and Sperzel tuners. I play through a Mesa/Boogie Royal Atlantic into a 2x12 Mesa cab with WGS Reaper HP and Veteran 30 speakers. It’s my dream guitar—a total tone machine. It sounds how I imagined it to, but it took many amps, speakers, and guitars to get here.
I’m just a hobbyist, but I’ve been playing since I was a teenager. I’m 56 now. Besides being a huge Alice in Chains fan, I love Robin Trower and got a chance to see him at the Moore Theatre in Seattle last May. It was a religious experience to see someone who’s practiced his craft and constantly tried to get better his whole life. I was third row and still am riding a high from that.
It’s a great time to be a guitarist, with new pedals released every day, it seems like. I have a modest board: Dunlop Cantrell wah, Fulltone CS-MDV mkII, Fulltone Robin Trower Overdrive, Mojo Hand Rook Royale (discovered by checking out Mike Zito), and an ISP Decimator II.
I play for my mental health. I forget about everything when I have the Mesa Royal Atlantic cranked. Then I go for a ride on my Harley and it makes for a pretty good day.
Send your guitar story to firstname.lastname@example.org.
Deliciously vintage details distinguish an affordable Les Paul that delivers authentically old-school performance, too.
Recorded with Friedman BE and custom-built tweed Deluxe-style amps.
0:00 – Bridge pickup, into Friedman BE lead channel.
0:45 – Switch to neck pickup.
1:02 – Bridge pickup, into clean-ish tweed-style amp.
1:14 – Both pickups.
1:25 – Neck pickup.
A well conceived, impressively executed, and affordable take on a star artist's vintage Les Paul. Many authentic vintage-style details. Articulate in overdriven contexts.
Thinner neck profile might turn away some players, despite vintage accuracy.
Epiphone Limited Edition Joe Bonamassa 1960 Les Paul “Norm Burst"
Joe Bonamassa is among blues-rock's most visible guitar-playing ambassadors. That stewardship role has led to more than a few pieces of gear marked with his imprimatur over the years. The newest, the $699 Epiphone Limited Edition Joe Bonamassa 1960 Les Paul Standard “Norm Burst," is impressive for the price. But it's an excellent guitar by any standard, that, in its beautiful, bright cherry burst finish, begs to be played, much like a seasoned vintage instrument does.
It helps that Bonamassa used one of the most iconic guitars from his own overflowing collection as inspiration for this Les Paul. The “Norm Burst" handle comes from the hallowed San Fernando Valley shop Norm's Rare Guitars, where Bonamassa picked it up. The original is a stunning Les Paul to say the least. And something about its exquisiteness clearly inspired Epiphone to look after the vintage-style details in this version.
The most basic features and specs of the Joe Bonamassa 1960 Les Paul are classic and familiar: a mahogany body with maple top, mahogany set neck, 24.75" scale length, 12" fingerboard radius, and dual humbuckers aimed squarely at PAF-style tones. Some changes to the formula are subtle. For instance, the AA-grade flame cap is a very thin maple veneer covering a thicker maple section, which is, in turn, affixed to the solid mahogany body. It does nothing to diminish the beauty of the guitar, however, and it's a great way to achieve the look of a pricey flame top without the expense.
Other details are more exacting. The long-tenon neck joint, Mallory tone caps, and 1960-style gold top-hat knobs with silver reflector inserts will please authenticity sticklers. The Epiphone also features a '50s wiring scheme—a reconfiguration of the tone pot wiring that many players prefer for its additional high-end clarity and more accurate tone-control performance. The guitar's pickups, a set of Epiphone ProBuckers, use alnico 2 magnets. (Original Les Paul PAFs used alnico 2, 4, and 5 magnets. Alnico 2 magnets typically deliver the warmest tonality and lowest power of these three types.) They also feature period-correct-sized bobbins, and measure 8.51k ohms in the bridge pickup and 7.86k ohms in the neck unit.
Like many modern guitars in this price class, the Epiphone substitutes Indian laurel for rosewood on the fretboard. Otherwise, the neck features Epiphone's '60s SlimTaper profile—a thin and ostensibly “fast" shape with a flat-ish back that purportedly replicates the feel of Les Pauls and other Gibson models from 1960. It's discernibly thinner than the profile that distinguishes Les Pauls from just a year earlier. Personally, I find this thinner shape more fatiguing on the left hand after a long session, and prefer Les Pauls with chunkier, more rounded '50s neck shapes. Many players will, no doubt, beg to differ. That said, this guitar played superbly right out of the case. At 9.2 pounds, it's classically Les Paul-hefty. Thankfully the street price includes a very nice Lifton-style hardshell case.
Before you ever plug it in, the Joe Bonamassa 1960 Les Paul feels lively, responsive, and resonant. That translates to a crisp, well-balanced sound once an amp enters the picture. Played through a Friedman Small Box head and 2x12 cab, a Carr Lincoln 1x12 combo, and several patches on the Fractal Axe-Fx III via studio monitors, the guitar sounded just like a good Les Paul should. But it also delivers tones that verge on sounding like a great Les Paul when you really get things dialed in.
The sound of a vintage Les Paul barely needs explaining, but this Epiphone speaks in that iconic voice very convincingly. There's lots of articulation when you pair it with overdrive from amps and pedals alike, lending plenty of harmonic interplay that adds sparkle to saturation and makes it a pleasure to dig in and play hard. Like any PAFs, these pickups are predisposed to a little grit even at clean amp settings. But the slightest attenuation of the volume cleans things up enough for rich jazz and country sounds. On the other side of the crunch spectrum, the Joe Bonamassa 1960 Les Paul acquits itself impressively well, excelling at power-chord rhythm, singing lead excursions, sizzling blues-rock, and even chunky vintage-metal.
The Limited Edition Joe Bonamassa 1960 Les Paul is a great value—particularly when you consider how much vintage spirit it possesses. It delivers most of the classic sounds and performance attributes players would want from the format. Individual tastes about neck shape might determine whether it's the perfect affordable Les Paul for you. But it's impressive that any perceived issues in the guitar's performance were primarily down to personal taste rather than build quality or execution. And most of these preferences are the things that fall by the wayside once you turn up and play with abandon—an environment where this Les Paul is right at home.
Watch the First Look: