Black Arts Toneworks Quantum Mystic

The Black Arts Toneworks Quantum Mystic is an overdrive/distortion pedal built around opamps, germanium clipping and a three-band active EQ. It was developed working closely with Mike Scheidt of the Portland, Oregon doom band YOB, and Black Arts Toneworks describes it as an adaptation of his favorite pedal from the early YOB records, turned into an updated and upgraded circuit¹. The maker says the EQ lets you cut frequencies for old school sounds, boost the final gain stage, or find sparkling clean boost tones, and that with everything dimed you get what they call a "ball molten lead that propels the Universe Throb"¹.

The pedal carries artwork by Arik Roper, whom the maker calls "another underground legend"¹. It was used on YOB's 2014 album Clearing the Path to Ascend².

Mike Scheidt and YOB

The Quantum Mystic exists because of a collaboration. Black Arts Toneworks worked with Mike Scheidt from YOB to design a distortion pedal³, and the maker says the starting point was Scheidt's favorite pedal from the seminal early YOB records, adapted into a new circuit¹. That favorite pedal, as the maker tells it, was an old Gray Distortion, "boiled down by a wizard, tweeked, manipulated, upgraded"¹.

The clearest documentation of the pedal in use is the 2014 YOB album Clearing the Path to Ascend. Black Arts Toneworks states the Quantum Mystic was used on that record², and RockBoard's PedalPedia entry for the pedal repeats the claim⁴. The limited tour edition tied to that album, described below, was hand signed by Scheidt himself⁵.

The controls: gain, volume and a three-band active EQ

The Quantum Mystic's control set is five knobs: Gain, Treble, Mids, Bass and Volume⁶. The EQ is active rather than the passive treble roll-off found on many overdrives, and the maker placed it between the gain stages rather than at the end of the circuit². That placement is what lets the EQ shape the signal feeding the final gain stage, not just the output.

The mid and bass controls are genuinely cut/boost controls, not just cutters. Builders who traced the original unit reported the Mids control sits about flat in the middle of its rotation with a scoop one way and a bump the other, and the Bass control behaves the same way⁶. For a player, that means the pedal can go from a scooped, old school setting to a pushed, forward midrange without touching anything else in the chain.

What circuit is the Quantum Mystic based on?

Black Arts Toneworks describes the Quantum Mystic as an opamp based distortion/overdrive with germanium clipping and a three-band active EQ¹. The design draws cues from Mike Scheidt's old Gray Distortion, reworked and upgraded¹.

DIY builders on the Guitar FX Layouts blog, who traced and rebuilt the circuit, characterized it more bluntly:

Guitar FX Layouts, on the circuit topology⁶

That reading fits the maker's own description of adding a three-band active EQ between gain stages to an existing distortion design². The builders also noted that the opamp choice is not critical to the sound: a TL074 is exactly two TL072s in one chip, so substituting one for the other makes no difference⁶. One builder's TL074 perf board build was, in their words, "dead quiet, high gain and the tone section works just like my v2.2.1 TL072 build"⁶.

History and limited editions

Beyond the standard pedal, Black Arts Toneworks released several limited runs of the Quantum Mystic:

• Custom White edition: a "Very Limited Custom White" version⁷
• USA Tour Edition: hand signed by Mike, in special edition colors⁸
• Limited Hand Signed Tour Edition "Clearing the Path to Ascend": a very limited edition of 25 pedals, sold in advance in September 2014, in a new maroon body with a gold mandala, hand signed by Mike, shipping approximately September 21, 2014. The maker later marked the run "ALL SOLD!!!"⁵
• REVOLUTION series (Custom Shop): a modded version with a toggle. The maker says the Revolution mod gives "earlier breakup, more aggressive sound and less compression"⁹

What builders and reviewers said

The Quantum Mystic has a second life as a DIY project. The Guitar FX Layouts blog published layouts for building a clone, and the comment thread there is effectively the pedal's review record, with builders reporting what the circuit does when built correctly.

The verdicts were mixed but leaned positive once the layouts were corrected:

• One builder wrote, "IMO, that thing sounds pretty darn good. i'll have to build it soon"⁶
• Another reported, "I'm running it front of a dirty OR15 as a boost and it works great"⁶
• A builder who added a JFET buffer in front of the circuit said it "cured the squeals" and that, used as a dirty boost, "it sounds awesome"⁶
• One builder who added a Stratoblaster-style boost and put the gain pot on a footswitch said the modified build "sounds outrageously good"⁶
• Later, on a corrected layout: "It's a massive sounding pedal using Vince's layout"⁶

The early DIY layouts had problems, though. Builders tracing the original unit found errors in the published vero layout, including a 10n capacitor at pin 2 of IC1 that should be 47n, affecting the high-pass filter at the gain stage, and a 100R resistor in the power supply filtering that is not present in the original, which instead uses a 1N4001 diode in parallel with the 100uF cap to ground⁶. In 2015 one participant concluded:

Guitar FX Layouts, on the early vero layout⁶

Later layouts and perf board adaptations resolved those issues, and the 2016 reports of quiet, high-gain builds reflect the corrected versions⁶.

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