D-Tar Mama Bear

Acoustic modeling meets acoustic guitars
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Acoustic modeling meets acoustic guitars

Why should electric guitarists have all the fun when it comes to digitally modeled sound? Isn’t there just as much quest for variety, experimentation, and a spirit of technological adventurousness from those of us who have round holes in the tops of our guitars? Apparently D-TAR thinks so, and has released the Mama Bear, a digital modeling preamp for acoustic guitars.

But doesn’t a review like this belong in a magazine like Guitar Player or Frets? Keep reading. The ability of a single instrument to sound like multiple guitars — and most importantly, to do so convincingly — is a valuable tool for any studio that records acoustic guitars. As a bonus, Mama Bear also offers a lot for onstage use.


The Mama Bear features proprietary AGE (Acoustic Guitar Emulation; see “AGE Before Beauty” sidebar page 52) modeling technology. Driven by a 32-bit, 100MHz floating-point 600MFLOPS microprocessor, Mama Bear emulates the sounds of classic, iconic guitars — including parlors, orchestra models, dreadnoughts, jumbos, resonators, and more. You can use the Mama Bear in two distinct ways:

n Correct, optimize, and enrich the tone of your existing acoustic

n Transform your guitar into an entirely different instrument — convert, say, your muddy-mellow dreadnought into a brassy biscuit-resonator blues axe or a sizzling Selmer/Maccaferri gypsy jazzer

Either way, the easy-to-use Mama Bear is tons of fun, and provides a wide variety of realistic, usable acoustic-guitar emulations . . . but it’s not just a one-trick pony.


In addition to modeling, Mama Bear has the usual signal-prepping features you’d expect from a quality acoustic guitar preamp. The front panel offers a single 1/4" hi-Z input (4.7M) and two continuous-level controls: Input, to match your guitar’s strength to the box’s processing circuitry, and Output, which does not affect the level from the XLR balanced out but does affect the 1/4" output, as an onstage monitoring benefit. Five switches provide on/off (with LED), phase, mute, analog low-cut (for eliminating rumble), and bypass functions, all of which come into play when wrangling acoustic signals (there’s also an Overload indicator LED). The back panel features separate 1/4" and XLR mono outputs. There’s also a ground lift switch and a jack for the wall-wart power supply.

To get up and running, just plug in, glance at the Quick Start card if you must, and go — it’s not even necessary to read the manual. Once you’ve matched levels for your particular system, it’s time for the fun stuff: modeling.


The Mama Bear devotes three controls to modeling: two 16-position rotary switches, and a continuous, center-detented wet/dry Blend control. The latency is undetectable (the manual lists 3ms), and the 24-bit A/D-D/A conversion and 94dB S/N ratio make for a very clean, studio-quiet component.

The Mama Bear’s strategy for modeled sounds considers both sides of the equation — input and output — for optimal effect. The Input Source control is a 16-setting source-matching selector, which “neutralizes” the sound of your guitar’s existing pickup and provides a baseline for the Mama Bear to perform its modeling magic. You choose the setting based on your guitar’s pickup — ceramic under-saddle transducer, magnetic soundhole pickup, etc. There are plenty of variations here to match virtually any pickup technology for all acoustic, acoustic-electric, and piezo-configured guitars out there. Position 16 gives no compensation.

Of course, you don’t have to stick with the matched setting; after you play around with the modeled instruments (called Target Instruments), you can come back to the Input Source and experiment with different compensation settings. This is analogous to how your digital camera applies lighting filters, like incandescent, fluorescent, flash, etc. It boosts the aspects that are lacking with the respective light source, but you can “misapply” them to amplify their compensation effect. The Mama Bear even offers some of the same pickup technologies, but with alternate EQ curves.


The Target Instruments control offers 16 different instruments (see the sidebar “On Target” on page 53) that touch on all the great acoustic models in history. For this review, I used a Martin J-40M with a Martin Thinline 332 under-the-saddle piezo pickup. I immediately went to the more radical incarnations — the Tricone Resonator, Biscuit Blues Resonator, Gypsy Jazz, and Hollow Body Archtop Jazz — to test the modeling engine’s mettle.

I was blown away. These were not caricatures of those well-known instruments, but living, breathing renditions. If you really play in the style that suits the Target Instrument, you will be rewarded with rich sounds. For example, in #16, Tricone Resonator, I tuned to an open A and played bottleneck licks and really steeled out the metallic, ring-modulated sound of a vintage Regal RC-51. Then, switching over to #14, Gypsy Jazz, I brushed up on my staccato alternate picking and went through my Django transcriptions of “I Got Rhythm” and “Lady Be Good.” When it was time to mellow out a bit, I played Johnny Smith’s classic chord-melody version of “Moonlight in Vermont” using the Hollow Body Archtop Jazz setting. The well-rendered results from these settings actually helped inspire my playing.

Switching over to the more subtle applications, the Mahogany Dreadnought sounded a little sharper and more focused for single-line passages than the Rosewood Dreadnought, which was warmer and fuller for chords and arpeggio work. Though the sounds went from the delightfully canny to the realistic, my only quibble is that I had to run both the input and output levels quite high to approximate the levels of other preamps in my studio. Fortunately, the Mama Bear is quiet, so running it hot doesn’t introduce any noise; I wouldn’t hesitate to use the Mama Bear in an exposed, critical-listening setting.


The Mama Bear is a rugged, well-built device that comes with all the usual controls you’d expect in an acoustic guitar preamp. The modeling section gives you a possibility of 256 sounds, though you’ll have to derive any further shaping through an outboard EQ. There’s no footswitch operation — either for bypass or stepping between Target Instruments. That, with the table-top housing and front-faced control configuration, makes Mama Bear more studio-friendly than stage-friendly.

But for the modeled sounds, and the subtle but perceptible gradations between different but related instruments, Mama Bear nails it. The distinctions between rosewood vs. mahogany versions of orchestra models and dreadnoughts, plus the dead-nuts accurate renditions of Jumbos and Dreadnoughts are real, convincing, and do come alive through playing, giving testimony to the Mama Bear’s AGE technology. (For my particular style, the Boutique Fingerstyle was a standout.) The Input Source compensations, when matched with your particular model, really do produce a fuller and more listener-accurate version of your own guitar, and the resonators and jazz instruments are not only great, they’re delightful and inspiring. Couple that with the additional tonal shaping that “unmatching” the Input Source provides (against your guitar’s type), and you have a wide, lustrous palette for shaping your acoustic sound.

Jon Chappell is the author of three “Dummies” books, including his latest, Blues Guitar for Dummies (Wiley Publishing).

Product type: Acoustic guitar modeling preamp.

Target market: Performing and recording acoustic guitarists who want to derive multiple acoustic guitar sounds from a single instrument.

Strengths: Highly realistic modeling. Musically useful (i.e., no over-the-top throw-away presets). Complete selection of acoustic guitar types. Great sound.

Limitations: No onboard EQ.

Price: $499 list

Contact: www.d-tar.com