Mulder Audio X-1 Review

Diode switching means drive diversity in Mulder Audio’s first overdrive.

Until recently, Colorado-based Mulder Audio exclusively made audiophile cables and wiring. A funny place from which to jump into overdrive stompboxes, you say? Perhaps not. The principles of amplification are pretty much the same whether it’s a stereo, guitar amp, or overdrive. And a stereo audiophile probably knows a few things about reducing noise that the average guitar goon can’t fathom.

Mulder Audio’s foray into overdrive, the X-1, has the beautifully made look of a pedal built to audiophile standards. Better still, is dishes heaps of dirty vintage-flavored goodness with a versatility that belies its streamlined design.

The compression is especially nice in the bass frequencies and doesn’t compromise low-end focus.

Unidentified Clipping Objects
The X-1 eschews ICs and op amps in favor of a simple single-silicon-transistor circuit. Much of its varied personality can be chalked up a set of germanium and silicon clipping diodes, which can be selected or combined via the pedal’s 3-way toggle. Different diode choices offer distinct breakup textures and shift the pedal’s bass response.

The X-1’s innards reveal a hand-wired circuit made with Mulder’s own high-fidelity wire and large-format capacitors. The unit has no circuit board—components are linked via a length of terminal strip.


Versatile. Excellent tone. Touch sensitive.

May be too vintage-sounding for some. Pricy.


Ease of Use:




Mulder Audio X-1

Overdrive Options Abound
The X-1’s control layout is stupidly simple. But between the changes in distortion texture yielded from its selectable diodes, the considerable gain on tap, and the impressively musical way the X-1 responds to guitar volume adjustments, the X-1 can cover everything from warm, clean boost to growling, hairy near-fuzz.

With the pedal’s volume and drive knobs maxed and the silicon diodes selected, the X-1 and an amp at the verge of breakup deliver the compressed sound and feel of a dimed low-power tube amp. (Imagine the chewy, harmonically dense fuzz of Deguello-era ZZ Top.) The compression is especially nice in the bass frequencies and doesn’t compromise low-end focus. And while it lacks EQ controls, the X-1 blended well with every amp and guitar combination I tried, thanks to its glowing transparency.

The X-1’s harmonic liveliness makes it ideal for overcoming backline challenges. At a walk-on gig, the X-1 and my Les Paul Jr. were enough to transform the provided Electro-Harmonix 44 Magnum power amp and no-name 1x12 cabinet from a sterile, lifeless canvas into a fire-breathing rig that kept up surprisingly well with the high–ticket boutique tube amps elsewhere onstage. When mated with an early-’70s 100 watt Marshall Super Lead, the X-1 added extra sparkle and grunt to the already burly Marshall, especially on the extremely satisfying setting that combines the relatively soft clipping of the germanium diodes and the harder-clipping silicon set.

The Verdict The X-1 Overdrive delivers that coveted trifecta of overdrive traits: touch sensitivity, harmonic richness, and a wide gain range, from near-clean to filthy. The $260 price may be too rich for some, but for players who crave overdrive variety and must contend with varying backlines, its many voices make it a valuable tool.

Photo 1

All photos courtesy SINGLECOIL (

We're getting close to the end of our journey. We've aged most of the metal parts on our project guitar, so now let's take care of the output jack, knobs, back plate, and pickguard.

Hello and welcome back to Mod Garage. This month, we'll continue with the aging process of our Harley Benton DC-Junior project guitar (which is a copy of a 1958 Les Paul Junior Double Cut), taking a closer look at the pickguard while aging the rest of the hardware discussed in the last part of this series ["DIY Relic'ing: Harley Benton DC-Junior Electronics"]. If you need a refresher on our aging process for hardware, refer back to "DIY Relic'ing: Break the Shine" for guidance. You can see the parts we'll be discussing today in their "finished" form, aka relic'd, in Photo 1.

Read More Show less

Mystery Stocking is almost here! Be sure to sign up for PG Perks so you don't miss it!

Read More Show less