From time to time, the MXR design team likes to invite guest designers to collaborate on pedals. It’s one of many things we do to keep a fresh and forward-thinking perspective, serving MXR’s ultimate mission to provide players with innovative, practical stompboxes that will stand up to the rigors of the road. In 2014, we worked with Italian pedal designer Carlo Sorasio to create the Il Torino™ Overdrive, and in 2015, we worked with Fuzzrocious Pedals’ Ryan Ratajski to create the MXR Bass Distortion.

This year, we worked with Shin Suzuki, Japan’s most celebrated pedal designer and the owner of Shin’s Music, where he also builds custom amps and guitars for artists. He leant us his intimate knowledge of a legendary boutique amp to create the Shin-Juku™ Drive, a pedal that provides smooth, wide open overdrive with tons of sustain and incredibly fast response time to every playing detail. The Shin-Juku Drive’s simple three-knob interface allows you to call up a wide range of sounds, from an organic boost to full on grinding overdrive, with a Dark switch to cut high frequencies for a darker, mellower sound.

Since we came out with the Cry Baby® 105Q Bass Wah, it’s been the #1 choice for bass players who want to sweeten up their grooves with the rich expressiveness that only a a Cry Baby Wah can deliver. With a specially designed potentiometer and custom EQ circuitry, the 105Q applies the wah effect to the mids and highs only, leaving your low end big, full, and round.

We took all that funk and functionality that made the 105Q the go-to for the world’s top bass players, and we put it into a housing that’s half the size and made from lightweight-but-sturdy-aluminum.

One of the coolest things about using effects is all the different ways you can combine them to create entirely different tonal palettes.

The MXR Bass Innovations line has a number of pedals that sound great when chained together, so we put together a list of our favorites. Feel free to experiment with the placement of each effect, as your mileage may vary, but these are our preferred arrangements.

If your music demands crystal clear notes and fluid, dextrous picking, get yourself a pack of Primetone Sculpted Plectra. Made with Ultex® for superior tonal definition and durability, each pick is burnished by hand so that its sculpted edges glide smoothly off your strings like a broken-in pick.

We developed these picks to have the elusive sound of tortoiseshell, and this is the closest we’ve ever gotten. Because tortoiseshell was infamous for being slippery, we gave every Primetone pick a grip with enough traction to give plenty of control but low-profile enough so you can still shift it easily in your hand. If you prefer a smooth surface, all models except the Jazz III are available in non-grip form, which have also been designed to have a slightly warmer tone.

The beveled edges were inspired by guitar players’ high mileage celluloid picks, whose edges have been worn into a natural “sweet spot” bevel that makes playing practically effortless. Some players even go as far as using emery board or sandpaper on their picks to get the same effect.

We decided to save you all that time and effort and just sculpt that sweet spot right onto the pick so you have it straight out of the package. Each pick’s edges are hand-burnished to further break them in and then inspected by one of our pick technicians.

We asked a handful of Primetone Sculpted Plectra players a couple of questions about why they’ve made the switch. Here’s what they had to say.

How does the Primetone Sculpted Plectra affect your technique and the way you play?

Tosin Abasi (Animals as Leaders; AAL Jazz III XL Grip): It’s really the perfect combination of material, shape and dimension. The beveled edges make picking feel fluid and unobstructed.

Zach Blair (Rise Against; Triangle Grip): I play hard, so I need a pick I can depend on not to break or wear down. I know that Primetone picks will stand up to everything I put them through.

Scott Fore (Former National Flatpicking Champion; Small Tri Grip and Smooth, Standard Grip and Smooth): The grip and bevel allow me to greatly vary my tone with subtle changes in the pick angle, and the beveled edge allows a greater string to pick contact area, which gives a much fuller tone. The grip surface prevents the pick from unwanted movement, but I also like the non-grip picks. Their darker tone allows for a big, fat, clear tone on even the brightest of guitars. Perfect picks for all styles of playing. The Ultex material doesn’t get scratchy or noisy from wear, which is another great benefit.

Jude Gold (Jefferson Starship; Editor, Guitar Player; Standard Grip): They have the classic vibe of celluloid picks, but they don’t break and they don’t slip or get sweaty, especially with that center grip. The beveled edges give you a bit of that comfortable, broken-in feel, and I love that. A broken-in pick has songs in it.

How do Primetone Picks open up your tonal possibilities?

Tosin Abasi: When the pick glides off the string, it produces a beautifully full and articulate tone. You can hear it even when the guitar isn’t plugged in.

Zach Blair: I’ve come to expect a certain tone out of the Primetone pick, one that’s dark and well rounded. It’s affected my playing and overall style immensely.

Scott Fore: The Primetone picks offer the best tonal possibilities of all pick materials available, even the revered tortoise picks. They sound full and clear, producing an open, balanced tone from the lowest note to the highest note.

Available in six shapes.

STANDARD

With a beveled edge, the tried and true Standard shape gets the smooth, quick release of a well-worn pick. The standard’s shoulders are also beveled for players who like to turn their pick around for a different sound.

TRIANGLE

The Triangle shape gives you three beveled edges and a wider gripping surface for greater control. Great for bass players.

SMALL TRI

The Small Tri is a shape that’s been gaining in popularity. Like the Primetone Triangle, the Primetone Small Tri features three beveled edges, but its smaller profile really lets you choke up and dig in with greater control.

JAZZ III

The quick-release Primetone edge enhances the Jazz III’s famous control, speed, and precision. Only available with the low-profile Primetone grip.

JAZZ III XL

Get the Jazz III XL shape’s tight maneuverability and laser-guided, lightning-fast tip with the hand-burnished beveled edges and flexible, snappy attack of Primetone Sculpted Plectra.

SEMI-ROUND

The warm and mellow sounding Semi-Round shape features three beveled edges and two different playing tips so you can easily change up your attack and your sound.

The M238 MXR® Iso-Brick Power Supply is designed for the demands of the stage and the rigors of the road. With ten fully isolated outputs and a lightweight, pedalboard-friendly housing that’s built like a tank, this potent piece of hardware will keep your pedals running with quiet, consistent power gig after gig.

Why does having isolated outputs make a difference? We asked the MXR design team to explain that and more, including several questions on how to get the most out of this wonderful power box. Get inside the Iso-Brick Power Supply below.

What are the advantages of fully isolated outputs?

When power outputs are fully isolated, there is no common electrical connection between them. This provides ground isolation between power sources, eliminating noisy ground loops and making high gain signal chains quieter. It also prevents one pedal from corrupting the power supply of the other pedals if something goes haywire.

Basically, having isolated outputs is like powering all of your pedals with high quality batteries.

Is there anything else in the M238’s design that helps to reduce noise?

Yes—aside from isolating the outputs from each other, we’ve ensured that each fixed voltage output receives a stable, low-noise voltage source by using linear regulators. The variable outputs are regulated by a hybrid design consisting of an adjustable buck regulator and two LC filters—which block switching noise—to simulate the smooth output of an adjustable linear regulator. This was done to minimize heat and power loss in the circuitry while preserving the output characteristics of an adjustable linear power source.

How do fully isolated outputs provide more protection to pedals than non-isolated outputs?

If pedals are powered from just one source—that is, if they aren’t isolated—they can potentially suffer damage if one of the effects experiences an overload or other voltage problem. With an isolated output, that potential damage source is kept from the rest of your pedals.

Is there anything in the design to prevent overheating?

We built in thermal protection for each output, so the M238 will automatically turn itself off if it reaches unsafe operating temperatures. The outputs are also protected against short circuiting via foldback current limiting.

Which types of pedals can be used with the Iso-Brick Power Supply?

You can use almost any pedal—digital or analog, positive or negative barrel—as long as it takes DC power and meets the voltage and current requirements of the M238’s outputs.

How can players make sure they’re matching pedals and outputs correctly?

It all depends on the voltage and current requirements of your pedals, and you need to know both before you ever connect a pedal to a power source. Digital pedals require more current—measured in milliamps (mA)—than analog pedals, so keep that in mind when allocating your outputs between the two types.

The M238 has six 9V outputs: two at 100mA, two at 300mA, and two at 450mA. The 100mA outputs have more than enough current—by far—for pretty much any 9V analog pedal, but many 9V digital pedals require more current. In that case, the 300mA and 450mA outputs will be more than enough for most digital pedals. If you’re only using analog pedals, it doesn’t really matter which output you use as long as the voltage matches.

The two 18V outputs and the two variable 6V–15V outputs adjustable are rated at 250mA, which is still enough juice for most digital pedals. The vast majority of digital pedals are designed to run on 9V power, however, so you’re likely to use the 18V outputs for analog pedals. If you have odd voltage requirements—up to 15V—or you want to “sag” a 9V analog pedal, then use the variable outputs.

How can I make sure the variable outputs are set to the right voltage?

The easiest way is to measure at the end of a connector cable with a multimeter. First, make sure the power supply itself is plugged in, and then plug one of the connector cables into one of the variable outputs. Set your multimeter to measure DCV; if yours doesn’t automatically detect voltage, select the 20 DCV setting. Set the voltage control about where you want it.

Next, use one of your multimeter’s probes to touch the inside center of the plug’s barrel, and use the other probe to touch the outside of the barrel. Your multimeter will then display the output’s voltage. Use the variable control to adjust as needed. Note: whether the number shown on the multimeter’s screen is positive or negative depends on which probe touched which part of the barrel, but that doesn’t matter for our purposes. The value will be accurate either way.

What is voltage “sag”? Which pedals can be “sagged” below 9 volts, safely and with good results?

“Sag” refers to the effect of a dying 9V battery. As batteries get used up, their voltage level goes down, and this changes the sound of certain 9V analog pedals. This effect is called voltage sag, and a lot of guitar players back in the day loved it so much that they would purposely use dying batteries to get it.

The variable outputs allow you to achieve the same effect without the hassle of managing a constant supply of under-powered batteries. Overdrives, distortions, fuzzes, and wahs tend to benefit the most from voltage sag, but you won’t hurt your pedal by under-powering. Feel free to experiment.

Can the M238’s outputs be combined?

Any output may be combined with any other when stacked in series. When combining outputs in parallel, however, you need to make sure that the outputs match each other in voltage.

Are there any features to help players troubleshoot problems?

Yes—the M238 has LEDs to indicate a good or bad connection on both the input and each of the outputs, which allows you to quickly identify the source of a problem.

What precautions should players take when using any type of power supply?

First and foremost, make sure the voltage and current specs of your pedals are compatible with the voltage and current specs of your power supply’s outputs. Ignore this information at the peril of both your pedals and your power supply.

As a general rule, don’t give your pedal too much voltage—for example, by plugging a 9V pedal into an 18V output—and don’t force an output to give up more current than it can handle—for example, by plugging a pedal that draws 250mA into an output that only has 100mA on tap.