Bass OD/DI/Preamp Pedal Roundup

We test four versatile and feature-laden bass stomps from Gallien-Krueger, Providence, Two Notes, and Tech 21.

One of the wisest decisions any bassist can make is to invest in a good DI box. They’re ideal as inexpensive and reliable interfaces for laying down tracks in studios large and small. They help make sure you’re heard in less-than-ideal venues with less-than-attentive sound guys. And they’re great for juicing up dead and muddy tones with an infusion of brilliance, body, and punch. Plus, if you’re a bassist with proclivities for filthier tones, using a solid DI box in addition to your rig is almost essential for ensuring your sound feels intense, and not a weak rumble, after the rest of your band kicks in.

Most of the road warriors, sound engineers, and techs reading this will know what I’m getting at. But if you’re anything like I was many years ago when I first heard about bass DIs, you might be thinking what I was then: This sounds about as exciting as buying a tuner pedal. Lucky for all of us, bass DIs entered the modern-tech era a while ago, and their continued evolution has resulted in bigger, badder, and more ambitious tools that go far beyond what DI boxes were capable of in the past. Technology’s obsession with all things micro has allowed for intricate multi-channel bass preamps to coexist with full compliments of EQ’ing, compression, cab emulation, high quality A/D conversion, and a wealth of analog and digital connections for routing and updating software.

The aforementioned highlights would be appealing to any bassist. But for those who really enjoy using grittier tones yet hate dealing with excessive noise and finicky EQ’ing, the compact and controlled environment within a modern bass DI is a godsend. And we specifically chose the four overdrive/DI/preamp pedals in this gathering with that type of player in mind.

The SansAmp Bass Driver DI Version 2 is an updated version of Tech 21’s popular pedal that doesn’t mess with the original’s excellent formula, but offers more features. Providence’s Brick Drive BDI-1 delivers gobs of juicy overdrive in a simple and straightforward package. If your ears perk at the sound of bells and whistles, Gallien-Krueger’s Plex brings a full complement of onboard features, from tuning to a USB recording interface. And the Le Bass from Two Notes Engineering sports a highly tweakable, dual-channel tube preamp that generates an array of absolutely brutal distorted tones.

To test each pedal’s mettle, I used a 2013 Fender American Precision bass outfitted with a Lollar P-style pickup, along with either a Gallien-Krueger 400RB or 800RB into an Ampeg 8x10. Despite each pedal being roughly intent on accomplishing the same goals, it was interesting to hear how unique they sounded compared to one another.

Click next or choose the di/preamp you want to learn about first:
Tech 21 SansAmp Bass Driver DI Version 2
Providence Brick Drive BDI-1
Gallien-Krueger Plex
Two Notes Audio Engineering Le Bass

Tech 21 SansAmp Bass Driver DI Version 2


Recorded using Gallien-Krueger 800RB head, Ampeg 8x10 cabinet, and PreSonus AudioBox iTwo interface.
Clip 1 - Heavy Downtuned Overdrive: Blend at 1 o'clock, treble at 11 o'clock, mid at 1 o'clock, bass at 1 o'clock, presence at 1 o'clock, drive at 5 o'clock, mid-shift switch at 500 Hz, and bass-shift switch at 80 Hz
Clip 2 - Clean Groove: Blend at 3 o'clock, treble at 2 o'clock, mid at 11 o'clock, bass at 11 o'clock, presence at 11 o'clock, drive at noon, mid-shift switch at 1000 Hz, and bass-shift switch at 80 Hz.

It’s hard to overstate the impact Tech 21’s SansAmp Bass Driver DI has had since its release in 1994. Few all-in-one DI packages have simultaneously delivered its caliber of tones and ruggedness while remaining so simple to operate. And it’s remained pretty much the same—until Tech 21’s recent unveiling of a second-generation version of the ubiquitous DI device. Version 2 contains the identical all-analog circuitry of its predecessor, but raises the ante by adding a smattering of updates geared towards the modern bassist.

Driven to the Edge
The build quality of the new Bass Driver DI improves on the solid reputation of the original by including enclosed jacks secured by metal nuts and opting for high-quality latching push buttons in place of the original’s slider switches.

With my down-tuned P and the drive set anywhere between 2 and 5 o’clock, the tone was heavy and guttural with an absolutely punishing midrange.

The pedal can be connected in a variety of ways, using the parallel output for a dedicated dry output and the XLR and main 1/4" output for sending the effected signal. It employs buffered bypassing and is powered by either a 9V battery or power supply, as well as being phantom-power operable.

The pedal has controls for volume, wet/dry signal blend, presence, and drive. It also features an expanded 3-band active EQ (+/-12 dB) with treble, midrange, and bass controls. There is no dedicated midrange dial on the original. There’s also a pair of new control buttons for shifting the center frequencies of the mids between 500 Hz and 1 kHz, and the center frequencies of the bass between 80 Hz and 40 Hz.

Ratings

Pros:
Delivers classic Bass Driver tone. Frequency shift switches and midrange dial help tailor the sound even further.

Cons:
A switch to completely bypass cabinet emulation would be nice.

Tones:

Ease of Use:

Build/Design:

Value:

Street:
$209

Tech 21 SansAmp Bass Driver DI Version 2
tech21nyc.com

Along with my P bass and the Gallien-Krueger 800RB, it was easy work getting a fantastic tone with plenty of thick, low midrange by setting the Bass Driver’s drive at 9 o’clock, everything else at noon, and then slowly increasing the presence to taste. When I switched to a different Precision tuned to C standard, a quick press of the bass-shift button to 40 Hz caused the walls to shake, yet still impressed me with how little it affected the tonality of the low end.

As its name implies, the Bass Driver excels at dishing out grinding overdrive. With my down-tuned P and the drive set anywhere between 2 and 5 o’clock, the tone was heavy and guttural with an absolutely punishing midrange. Lesser drive settings beginning at 11 o’clock softened the low end and gradually accentuated the attack as I dialed down the gain farther. Overall, I’d describe the resulting sound as an aggressive mid-focused grit that grows angrier as more gain is applied, but without the harsh, ear-fatiguing frequencies that often result from such heavy saturation.

The remaining push buttons let you attenuate the XLR output by -20 dB, boost the main 1/4" out by +10 dB, and engage either ground lifting or phantom power through the XLR jack—handy features for direct recording, especially if the input trimmers on your interface are sensitive. Meanwhile, the Bass Driver’s speaker simulation is still fantastic. My only gripe is that you can’t bypass the circuit and use the pedal as simply a preamp. This wouldn’t have been an issue years ago, but these days many players prefer to record with DAWs and their own cabinet impulse responses. As a workaround, Tech 21 states that the blend knob can be turned all the way down and the EQ, level, and boost will still function.

The Verdict
The second incarnation of Tech 21’s SansAmp Bass Driver DI hits high marks, which is a natural conclusion given that it retains the meat and potatoes of the original yet adds some more to the pie with the slight but welcome changes it’s undergone. The “it ain’t broke, don’t fix it” approach works in its favor since it’s still easy to get a killer tone almost immediately, and even better ones after spending more time with it. If you’re a current Bass Driver devotee and are mulling over whether this version is worth the upgrade, I guess you need to ask yourself how much you’re dying for a dedicated midrange control and the added frequency shift functions. If you’re a bassist who’s never explored the possibilities of a Bass Driver DI, you owe it to yourself to check out what many bassists have before you.

Providence Brick Drive BDI-1


Recorded using Gallien-Krueger 400RB head, Ampeg 8x10 cabinet, and PreSonus AudioBox iTwo interface.
Clip 1 - Pedal engaged 11 seconds in: clean level 1 o'clock, drive level noon, mix 1 o'clock, drive gain 4 o'clock, bass 1 o'clock, mid 11 o'clock, treble noon, presence 1 o'clock, mid-freq 10 o'clock.
Clip 2 - Clean tone, no drive: clean level-1 o'clock, bass 11 o'clock, mid 10 o'clock, treble 11 o'clock, presence 9 o'clock, mid-freq 10 o'clock.

The dual-channel Brick Drive BDI-1 from Providence takes a refreshingly straightforward approach to tone crafting. Though it has a lot of controls and connection options onboard, it doesn’t hide anything within complicated secondary functions. And under the hood, both clean and overdriven tones benefit from the company’s proprietary Vitalizer B circuitry that’s optimized for bass guitar.

Thick as a Brick
The BDI-1’s clean channel and overdrive channel each sport individual volume dials and can be blended using the mix knob when in drive mode. The two channels share the EQ section, which includes a presence control for ultra-high frequencies and a mid-freq dial for adjusting the midrange’s center frequency. Next to the mid-freq control is a switch that assigns bypass or muting duties to the left-side footswitch.

I was treated to a terrifically warm tone with a thick and rounded midrange, complimented by smooth highs and soft lows.

In addition to standard 1/4" input and output jacks, there’s a 1/4" direct output jack—labeled “VZ Thru”—that’s fed from the pedal’s Vitalizer B circuit for direct patching with an additional amp or another device, such as a tuner. There’s a balanced XLR output with switchable ground-lifting for sending the effected signal straight to a mixer or recording interface. Power is supplied using the included 12V adapter, which is boosted internally to 21V to increase the dynamics and headroom of the circuit.

Providential Sound
With my P bass feeding the input of the BDI-1 and a Gallien-Krueger 400RB pumping the signal to the Ampeg 8x10, I dived into the pedal’s clean channel with its volume set at 11 o’clock and the EQ and presence controls set to noon. I was treated to a terrifically warm tone with a thick and rounded midrange complimented by smooth highs and soft lows.

Ratings

Pros:
Highly responsive and tweakable midrange. Versatile, with smart mixing options. Low learning curve.

Cons:
Bass control is most effective at higher ranges. Channels share the EQ section.

Tones:

Ease of Use:

Build/Design:

Value:

Street:
$259

Providence Brick Drive BDI-1
providence-ltd.com

Turning the EQ’s mid frequency dial yielded a wide range of usable tones that rarely resulted in an annoying honk or shrill spike, and both the treble and presence controls managed to maintain a smooth sheen over the highs—even when I pushed them to their highest ranges. I did, however, have a little trouble dialing in a thicker low end for harder rock tones, since the majority of the bass control’s effectiveness seemed to lie at 2 o’clock and beyond. Compared to the other EQ controls, its taper didn’t feel like it was spread as evenly.

The pedal’s drive channel might be a touch limited by sharing an EQ with the clean, but Providence certainly had the right idea by providing so much control over its presence in the mix. Having separate channel volumes and a dedicated mix control made it easy work to dial up a gut-wrenching overdrive while keeping the clean signal low enough to be barely noticeable—but still present enough to add more punch and clarity to the lows and midrange. (My personal sweet spot was setting the clean tone to take up about a third of the mix.) That said, some players might not even bother fiddling with mixing in the clean signal at all, since the BDI-1’s overdrive is so full, dynamic, and clear when used on its own.

Like the clean channel, the drive is highly dependent on where the mid controls are set, which my mid-leaning P agreed with easily when dialing up some Geezer Butler-inspired bark. The channel really started screaming when I pushed the gain up past 2 o’clock, which resulted in a fluid and aggressive grind similar to bi-amping a JCM800 with an SVT.

The Verdict
The Providence Brick Drive BDI-1 should be on the radar for any bassist who gravitates toward tones with a big and bold midrange—especially if those tones are of the filthier variety. The amount of control over the pedal’s low end could use a little tweaking, but the overall degree of ease involved when dialing in tones can’t be overstated. I spent less time toe tapping and more time getting lost in exploring the sounds it has to offer. Simply said, the BDI-1 is a solid pedal that does what it says it does without making things harder than they have to be.

Gallien-Krueger Plex


Recorded using Gallien-Krueger 800RB head, Ampeg 8x10 cabinet, and PreSonus AudioBox iTwo interface.
Clip 1 - Clean Detuned Groove: Bass at 11 o'clock, lo-mid at 1 o'clock, hi-mid at 9 o'clock, treble at 11 o'clock.
Clip 2 - Heavily Overdriven: Overdrive Mode #5, drive at 2 o'clock, bass at 1 o'clock, lo-mid at 1 o'clock, hi-mid at noon, treble at 10 o'clock.

With features like onboard tuning, USB connectivity, and EQ voicings taken from four Gallien-Krueger amps, the new GK Plex is clearly vying to be a player’s all-in-one personal assistant for bass tone. It wasn’t the simplest pedal in this roundup to master, but the Plex’s everything-but-the-kitchen-sink approach makes it a well-rounded option for grab ’n’ go gigging and recording.


A Sum of Its Parts
The Plex’s rugged enclosure shares a lot of commonalities with modern desktop recording interfaces. Nearly every edge and corner of its matte-black-finished aluminum enclosure is comfortably rounded and chamfered, and held together with top-mounted hex screws to complete its industrial-looking build.

The front panel’s top row of dials features an input trimmer and a 4-band active EQ with secondary modes for bass boosting, midrange contouring, treble attenuation, and presence. The next row includes controls for overall volume, EQ voicing selection, and the amount of volume, drive, and drive intensity when in the footswitchable overdrive mode. The last two dials in the second row run the compression section’s full menu of controls for level, attack, threshold, and ratio.

The pedal’s EQ emulation of an 800RB was very accurate, and allowed my P to really sing with the thick and smooth lows the amp is known for.

Engaging the compressor is accomplished via a single tap of the dual-purpose compressor/tuner footswitch. Double-tapping this same footswitch activates a chromatic tuner display on the LED readout—a feature that’s appealing in itself, though the double-tap required to turn it off seems excessive. (G-K says the next firmware update will change this to a single tap.)


It should be noted that the position indicators on the control knobs share two bi-color LEDs that are located underneath and closest to the second and fourth vertical columns of knobs. This wasn’t a big deal unless, for example, I had the low mid or level/drive controls dialed to a lower-range setting, which seemed to position their respective transparent indicators right over one of the shared LEDs. And because the LEDs are extraordinarily bright—especially when illuminated white—there were occasions when I had difficulty even seeing the neighboring controls.

The Plex houses 1/4" jacks for input, output, send, and return, an XLR balanced DI out with switchable ground lifting and pre/post EQ’ing, two 1/8" jacks for headphones and aux-in sources, and a USB jack that enables firmware updates and turns the unit into a full-fledged recording interface. The Plex is fired-up by an included 9V power supply.

Ratings

Pros:
Compact and robust. Ballsy vintage-flavored overdrive. Feature-packed and useful for many scenarios.

Cons:
Display readout and secondary modes could be more intuitive. Control-knob LED brightness can be excessive depending on settings. Tuner footswitch requires double-tap to disengage.

Tones:

Ease of Use:

Build/Design:

Value:

Street:
$319

Gallien-Krueger Plex
gallien-krueger.com

Rawhead Plex
After plugging my P into the Plex and the pedal’s output into the effects return of a GK 800RB head, I set the Plex’s EQ controls to noon, pressed the pedal’s master/voice knob, and twisted it so the LED readout displayed “1”—the setting for 800RB EQ-voicing emulation. Take note: Because the display only shows numerical values, you’ll need to memorize the page in the manual that lists which number corresponds to each selection for any given control. But since there are about 30 examples, making a copy and taking it to gigs and sessions until you know them by heart might be easier. And with eight different secondary functions on the Plex, it does take a bit of time and effort to get to know this pedal.

The pedal’s EQ emulation of an 800RB was quite accurate, and allowed my P to really sing with the thick and smooth lows the amp is known for. The ranges of the EQ controls weren’t as wide as those on an 800RB head, but they were wide enough to deliver a similar gamut of low-mid-heavy rock and crisp slap-bass tones. The onboard compressor—which offers compression ratios from 2:1 up to 20:1—was useful when I wanted to tighten up my sound, and it remained silky smooth throughout the full range of its controls.

The Plex offers five overdrive modes with varying degrees of intensity. The first mode added a subtle growl and noticeable increase in thickness to my sound. And the added punch in the midrange served up a ballsy SVT-esque tone, which I enjoyed using for cleaner passages after rolling my P’s volume down slightly. As I transitioned through modes 2, 3, 4, and 5, the intensity of the low-end and mids grew alongside a viciously raw overdrive, and the fullness and roundness I was hearing was spot-on for the Plex to sit comfortably with heavy blues-based rock and metal in the vein of Black Sabbath.

The Verdict
The Plex is a great solution for bassists seeking an all-in-one recording, gigging, and practice unit. And the texture of its overdrive will appeal to players who lean towards classic blues-rock and ’70s metal tones. Yes, there are less-expensive alternatives out there, but few with as many features, functions, and tone-shaping tools as this one. Mastering the secondary modes and hidden functions will take some time, but if you’re willing to put in the effort, the Plex has the potential to be an infinitely rewarding tool.

Two Notes Audio Engineering Le Bass


Recorded using Gallien-Krueger 400RB head, Ampeg 8x10 cabinet, and PreSonus AudioBox iTwo interface.
Clip 1 - Channel A (clean): gain at 11 o'clock, level at 10 o'clock, bass at noon, treble at noon.
Clip 2 - Channel B (dirty): gain at 3 o'clock, sweep at 10 o'clock, level at 11 o'clock, bass at noon, midrange at 1 o'clock, treble at 11 o'clock.
Clip 3 - Cold Fusion (Metallic Overdrive): Channel A - gain at 11 o'clock, bass at 2 o'clock, treble at noon, fusion at 1 o'clock. Channel B gain at 4 o'clock, sweep at 11 o'clock, level at 3 o'clock, bass at 10 o'clock, midrange at 2 o'clock, treble at 2 o'clock.
Clip 4- Hot Fusion (Heavy Overdrive): Channel A - gain at 5 o'clock, bass at 10 o'clock, treble at 1 o'clock, fusion at 2 o'clock. Channel B - gain at 5 o'clock, sweep at 5 o'clock, level at 2 o'clock, bass at 11 o'clock, midrange at noon, treble at 9 o'clock.

The Le Bass from Two Notes Audio Engineering is the low-flying offering in the company’s tube-based preamp pedal series. Its clever and intuitive interface gives an impressive amount of control over two separate channels—one voiced for clean and responsive tones, and the other for overdriven roar—which can be utilized to great effect individually or simultaneously.

A Little of This, a Little of That
At the heart of the Le Bass is a Ruby 12AX7 tube that’s running at a massive 200 volts. In addition to 1/4" input and output jacks, the Le Bass houses a post-EQ effects loop, a thru output, MIDI in and out, an 1/8" headphone output, a balanced DI out with ground lift, and a switch for engaging the pedal’s analog speaker-simulation circuit. The pedal is powered by an included 12V supply.

The plethora of knobs, switches, and jacks on the Le Bass might be a little overwhelming at first, but they make a lot of sense if you pay attention to how they’re grouped together. Channel A includes dials for gain, volume, bass, and treble. Channel B is governed by six controls for bass, mids, treble, gain, mid-sweep, and volume. Nestled between the control groups is the fusion-mode switch for selecting either “cold” (parallel) or “hot” (series) mode when the fusion feature is engaged to run the channels simultaneously—accomplished by stomping both footswitches at the same time. Below the mode switch is the fusion dial that administers channel A’s level when in fusion mode.

It was initially a little thin on the low end until I turned up the gain to at least 1 o’clock, which was also the point at which the beast inside the box began to rattle its cage with a cranked SVT-like snarl.

An Axe to Grind
I connected the Le Bass between my P bass and the GK 400RB/Ampeg 8x10 pairing. With channel A’s bass and treble controls set to noon and the gain set to about 11 o’clock, the tone was squeaky clean and extraordinarily detailed. Single notes played in the lower registers had a beautifully throaty midrange and a low end that was warm, full, and corpulent. The range of tones afforded by the dual-band EQ was impressive, to say the least. I was able to easily transition from fat-bottomed, hard rock tones to tight and percussive slap-friendly sounds with only minor adjustments to the knobs.

Things took a much more focused turn after I switched to channel B and set its gain to 10 o’clock and the EQ to neutral. Compared to the warm and bubbly quality of channel A, channel B sounded tighter with a bigger emphasis on the lower midrange, which gave its tones an overall heavier and more aggressive quality.

Ratings

Pros:
Easy to use with plenty of connection options. Low noise. Superb articulation. Gobs of roaring overdrive. Fusion modes offer even more versatility.

Cons:
Channel B can sound thin when using low gain. Hot fusion can sound congested under extreme amounts of drive.

Tones:

Ease of Use:

Build/Design:

Value:

Street:
$299

Two Notes Le Bass
two-notes.com

It was initially a little thin on the low end until I turned up the gain to at least 1 o’clock, which was also the point at which the beast inside the box began to rattle its cage with a cranked SVT-like snarl. The added gain also seemed to grease the wheels of the pedal’s responsiveness, which allowed me to bring in a meatier midrange punch by digging into my Precision’s strings a little harder.

Engaging the fusion feature is an easy, on-the-fly maneuver. The footswitches are placed far enough apart for accurate individual stomping, but still close enough together that my size-11 feet had no issue making contact with both simultaneously. Thanks to its parallel operation, the cold mode was the more articulate of the two. By giving me the ability to effectively blend in channel A’s fat-bottomed cleans with the sharp and strident overdrive of channel B, it not only allowed for some seriously earth-moving tones, but provided an excellent way to fill out channel B’s thinner low-end with lower-gain settings.

Hot-fusion mode picked up where the cold left off, starting with a guttural doom-metal howl and ending with a filthy Moog-like grind that would bring a smile to the face of the most jaded industrial-metal fan. The EQ controls weren’t quite as effective in hot-fusion mode since they were cascading in series, but there were still discernable changes when I swept through each of their ranges. What was most noticeable, however, was the surprisingly low amount of noise—even under the heaviest doses of overdrive.

The Verdict
With its gentle learning curve, hookup options, mammoth-sized tones, MIDI capabilities, and more, the Two Notes Le Bass excels as a jack-of-all-trades stompbox. But above all its advantages, the fusion modes are the real stars of this grindhouse. When tweaked properly, they’re capable of unleashing some of the more fiercely vicious overdriven bass tones you’re likely to hear. For bassists yearning to add a unique blend of punch and grind from a portable, potent package—bon appétit when you get an opportunity to check out the Le Bass.

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