IT’S A GREAT TIME TO BE A BASS PLAYER with a weakness for bass-friendly preamps. Never before have there been so many cool and portable options, both tube and solid-state. Most of us associate tube preamps with “warmth” and solidstate preamps with “clarity,” but there are many definitions of “warmth” and “clarity,” and many shades in between. Sonic Farm’s 2DI4 Pentode Direct Box is a perfect example
The 2DI4 is housed in a strong steel box that’s a hair under five-and-a-half pounds, and the switches and buttons are solid; each click feels decisive. On the front of the unit are an input jack, an unbalanced ¼" amp output, a green LED that glows red when overdriven, a gain button, a power LED, push-button access to triode and pentode tube settings, two small holes that hide tweakable low- and high-frequency boost levels (I left them at the default, maximum settings), and a “chickenhead” trim knob, which handles output. EQ happens courtesy of a trio of threeposition switches: 0dB/–12dB/mute selector, three-position lo boost, and three-position hi boost. Around back are DI, line, and xlr outputs, a ground lift, the fuse, voltage switching, and the power switch.
Using the di out into a Digidesign Digi 003 board running Logic X, I recorded a stock, maple-neck 1958 Fender Precision strung with D’Addario nickels. The 2DI4 was absolutely quiet, and in triode mode, the ’58 P’s tone as captured by the 2DI4 was detailed, clear, and strong, with just a touch of warmth. The loud pop that occurred when engaging and disengaging the mute or using the boost switches after changing tube settings was a bummer, but I found the EQ changes gentle, subtle, and musical. The lo boost, switched to the left, added clear warmth at 300Hz; to the right was another bump at 500Hz. Similarly, the hi boost switched to the left added top end at 2kHz, and to the right, at 4kHz. Putting either switch in the center left the tone unaffected. Pushing in the gain button deactivated the hi and lo boosts but hit the single EF86 tube harder, bumping up the output by 5dB in triode mode and 9dB in pentode mode. I preferred using the boosts for more specific frequency tweaking, turning up the trim knob to adjust output level.
The 2DI4 sounds perfectly fine in triode mode, but pentode mode brought out a whole other beast. The 9dB gain surge and turbocharged, harmonically rich character were instantly noticeable. Each frequency boost was pleasingly musical while still maintaining the character of my instruments. Switching back to triode mode gave a mellower voice, with less output but way more headroom, and it was closer, perhaps, to what many folks think of as “tube tone”—rounder, with a softer, less prominent attack.
When I used the amp out jack, however, things were a little different. I plugged in an active Atelier Z 5-string with Dunlop Super Brights, sending the signal from the amp out to the power section of an Aguilar DB 750 and driving two DB 112 1x12 cabs. The sound was clear, but the differences between EQ points were imperceptible, and the trim knob was ineffective.
Using the line out jack to Bergantino IP112 1x12 and HT-112-ER 1x12 cabs did the trick, though. In pentode mode, an Elrick Gold-series prototype 6-string sounded meaty and alive, and both lo boosts were subtle but pleasing. Instead of making the tone fatter across the spectrum, boosting the 2DI4’s lows highlighted just the right low-mid frequencies in conjunction with the Elrick’s onboard Bartolini preamp. Similarly, boosting the highs imparted two types of “air,” right in the sweet spots; putting the bass into passive mode yielded similarly pleasing results. Overall, the 2DI4’s voice leans toward strong and stout instead of fat and pillowy, but there’s nothing glassy, shrill, muddy, or mushy about this preamp.
The 2DI4 strikes a balance between sophistication and simplicity. The tonesculpting options are few but well chosen, and the 2DI4 preamp in pentode mode roars like a lion. If you’re in the market for a portable, muscularly transparent hybrid tube-pre/DI with limited but supremely musical options, you’ve probably already heard about the 2DI4. Go try it!
2DI4 Pentode Direct Box
Pros Detailed and transparent; frequency boosts in the sweet spots
Cons EQ too subtle from amp output; loud pops when changing settings
Bottom Line A hybrid tube-pre/DI that boasts well-chosen EQ options and a singular balance of clarity and warmth.
Tube modes Triode & pentode
Frequency response 10Hz–50kHz ±3dB
Maximum gain 54dB at line output, 32dB at DI (mic level) output
Harmonic distortion <2% before clipping
Maximum line output level 30dBu
Minimum output load 60ῼ
Connectors xlr DI and line output (balanced only)
Instrument input ¼" unbalanced, mono
Input impedance 2.2Mῼ
Amp output " unbalanced, buffered mono
Power consumption 15W
Operating voltage 110–120VAC or 220–240VAC, switchable
Made in Canada