EarthQuaker Devices Scrolls Bass Drive / EQ / DI Box

A collaboration between EarthQuaker Devices and Kentaro Nakao.

Scrolls Bass Odyssey is a sonic pilgrimage through the entire universe of electric bass tone. From Motown to Metal and everywhere between and beyond. With a tube amp-like drive channel, an active EQ channel with three push-button switches for one-click tone sculpting, buffered parallel out, onboard effects loop, and balanced XLR out featuring just a splash of analog filtering to emulate a speaker cabinet, Scrolls is a powerful, modern tool that’s compact and versatile enough to be the only thing you need to play a session or show other than a bass.

From Motown to Metal

EQ Channel

The left side of Scrolls features a full suite of active EQ controls including audiophile-quality Bass, Middle, and Treble controls. The secret weapon of Scrolls' EQ section is the Variable Frequency control with the ability to cut/boost frequencies from around 20 Hz to 10 kHz—making it the perfect tool for cutting out the mud and boosting the high-end. Within the EQ section, you’ll find three push button switches that serve as potent assets for one-click tone sculpting.

Drive Channel

On the right side of Scrolls, you’ll find the Drive channel featuring a versatile, tube amp-like distortion. Key amongst the Drive section features are the Blend knob, which enables you to adjust the amount of clean signal present in the overdriven signal, and the position of the Bandwidth knob determines where the clipping is most prevalent—lower frequencies counterclockwise and higher frequencies clockwise. Together, the Blend and Bandwidth knob can be adjusted to ensure the low-end response remains wide, deep, and full when using the Drive section.

The Brains of Your Signal Chain

Scrolls features three outputs that all work simultaneously: a buffered parallel out for sending clean signal to an external destination like an amp, tuner, DI, or other effects; a balanced XLR out to run Scrolls directly to front of house or into a recording interface; and a standard ¼" output. Scrolls also features an effects loop that lives between the Drive and EQ channels. This enables you to place modulation, time-based, or any other effects you’d normally place after dirt pedals (including more dirt pedals) after the Drive channel, while still retaining all the tone-shaping capabilities of the EQ channel.

Controls

EQ Controls

Level: Output volume control when the EQ controls are active. Set the knob at noon for unity, turn clockwise to boost the output signal, turn counterclockwise to cut the output signal.

Vari: Boosts or cuts the Variable Frequency control. Position this control at noon for unity (marked with a center detent in the potentiometer.) Turn clockwise from noon to boost the Vari-Freq, or counterclockwise to cut.

Vari-Freq: Variable frequency control for fine-tuning your tone. Adjustable from approximately 20 Hz to 10 kHz.

Treble: The center position is flat and marked with a center detent in the potentiometer. All settings above this point boost the treble and all settings below cut treble.

Bass: The center position is flat and marked with a center detent in the potentiometer. All settings above this point boost the bass and all settings below cut bass.

Middle: The center position is flat and marked with a center detent in the potentiometer. All settings above this point boost the middle and all settings below cut middle.

Deep: 80 Hz Boost.

Process: Low-mid scoop for a more modern sound.

Bright: 5 kHz Boost

EQ Footswitch: Activates the EQ channel

Drive Controls

Level: Output volume control for the Drive channel.

Blend: Blends between your clean signal with the Drive signal. Turn the knob fully clockwise for maximum crunchiness.

Drive: Controls the intensity of the overdrive.

Bandwidth: Determines where the clipping is most active. Turn the control counterclockwise to activate low-end clipping for a warmer, softer, rounded, and overall more subdued tone. Turn the Control clockwise and activate High-end clipping for a present, focused crunch with a tighter low-end.

Tone: Low pass filter enabling you to shape the frequency of the Drive channel. Turn counterclockwise to reduce highs.

Drive Footswitch: Activates the Drive channel

Outputs

Parallel Out: Buffered output carrying your clean signal that is always active. This allows you to route your clean signal to external destinations (amp, DI, separate pedal chain, tuner, etc.)

Direct Out: Balanced XLR out with a subtle amount of analog filtering added to the signal path to simulate the tonal characteristics of a bass speaker cabinet.

Ground Lift: Press for ground lift on the XLR output.

Effects Loop: Situated between the Drive and EQ stages. Hard-wired into the signal path and remains active at all times.

Design Notes

The Scrolls Bass Odyssey was born from a partnership with Japanese bassist and longtime EarthQuaker Devices friend Kentaro Nakao (Number Girl, Crypt City). His vision was to consolidate vintage and modern bass tones into a single, highly portable unit.

In Japan’s densely populated cities, gigging can become a logistical hurdle. Venues are often tucked away at the very top or bottom of steep staircases and musicians are frequently at the mercy of whatever backline equipment happens to be available.

"I am constantly playing shows in every type of venue you can imagine," Kentaro explained, "so having my sound in a portable rig is a must—that’s why I’ve been a big believer in preamps for a long time."

For Kentaro, the two most important foundational elements of the design were a full-range of EQ control and the ability to shape overdriven tones. The EQ channel is designed to be completely transparent when the knobs are set to noon, ensuring the bass retains its inherent tone. Three push buttons offer quick tone sculpting: Deep boosts 80 Hz for booming lows, Process scoops mids for a punchy modern tone, and Bright activates a 5 kHz boost for attack.

Inspired by a rare overdrive in Kentaro’s collection, the Drive channel delivers versatile, tube amp-like distortion with precise low-end command. To maximize the pedal’s tone-shaping capacilities, Vari-Freq control was added to the EQ channel and Bandwidth control to the Drive channel.

"These two knobs have enabled me to fine-tune my sound to fit each specific playing situation more than ever before," Kentaro noted.

Designed to serve as the brains of your signal chain, Scrolls includes an effects loop right between the Drive and EQ channels, a buffered parallel out for sending a pristine clean signal to an external destination, and a balanced XLR out featuring a 100% analog speaker cabinet simulation.

"Most XLR outs tend to have a harsh top end that sounds nothing like what is coming out of the amp, especially when dirt is involved," EarthQuaker Devices Founder/President Jamie Stillman said. "I thought it would be useful to add a bit of natural filtering so what is sent to front-of-house is much closer to what is coming out of the amp."

Scrolls began as a friend's request for the ultimate portable rig. Now, it’s a universally indispensable tool for every bassist.

Tech Specs:

Dimensions 4.75 x 4.50 x 2.25 in. (121 × 114 × 57 mm) with knobs

Current Draw 70 mA

EQ Input Impedance 10 MΩ

EQ Output Impedance <1 kΩ

Drive Input Impedance 500 kΩ

Drive Output Impedance 100 Ω

Parallel Input Impedance 10 MΩ

Parallel Output Impedance 100 Ω

Direct Output Impedance 100 Ω

Switching

Scrolls uses relay-based true bypass switching. Since the switching is relay-based, it requires power to pass a signal. The EQ side uses standard on/off switching, the Drive side uses Flexi-Switch® Technology.

Power

This device takes a standard 9-volt DC power supply with a 2.1 mm negative center barrel. We always recommend pedal-specific, transformer-isolated wall-wart power supplies or multiple isolated-output supplies. Pedals will make extra noise if there is ripple or unclean power. Switching-type power supplies, daisy chains and non-pedal specific power supplies do not filter dirty power as well and let through unwanted noise. DO NOT RUN AT HIGHER VOLTAGES!