Musicians and engineers looking for rich, natural tube tone in a DI and preamp format will appreciate the LBDI (Lunch Box DI) and RBDI (Rack Box DI). Both units are fully Class A, all-tube direct boxes and instrument preamps designed to deliver harmonic warmth, fast response, and high headroom. Their shared 12AU7-based circuit runs at a full 320V for true tube performance, avoiding the compromises of low-voltage designs.
Two Versions, Same Sonic Power
The LBDI is housed in a compact "lunch box" chassis with a chrome handle, ideal for performers who need a tough, portable solution. The RBDI fits into a 1U rack, making it a great fit for studio and touring setups. Both units include international auto-switching power supplies, so they’re ready for use around the world without hassle.
Tone Control and Flexibility
Each unit includes a Hi Z input that supports passive and active pickups. A front panel HIGH/LOW gain switch lets users shape their sound by selecting different stages of the tube circuitry. Input and Output Gain controls allow you to push the tubes from clean and open to rich and saturated.
The 3-band tube EQ is true bypassable and features:
- Bass: ±15dB
- Midrange: ±6dB
- Treble: ±10dB
The Bright switch adjusts high and low frequencies based on input gain. At lower gain levels, it brings out clarity and reduces muddiness. As gain increases, the effect gently fades out to maintain balance and avoid harsh tones. When paired with EQ settings, this setup allows for simultaneous frequency cuts and boosts, offering a broad range of tonal shaping options.
Reamping Made Simple
A dedicated line-level reamp input allows recorded tracks to pass through the tube circuit for added harmonic depth and tonal color. The RBDI includes a front panel switch that toggles between reamp input and live Hi Z input, allowing fast source changes without cable swapping.
Also Ideal for Harmonica Mics
With up to 53 dB of gain, the unit can directly drive high-impedance mics, including harmonica mics with 1/4" outputs, without needing extra gear.
Premium Build, Inside and Out
These units are built with attention to quality and longevity. Components include:
- Hand-wound output transformers
- NOS Phillips ECG 12AU7 tubes
- WIMA, Panasonic, and TRW capacitors
- Metal film resistors
- Japanese TOCOS sealed potentiometers
- Omron audio-grade relays
- Custom CNC-machined aluminum knobs
- Powder-coated steel chassis with dual-tone finish
Additional Features:
- Phase reversal switch
- Ground lift switch
- Front panel Thru jack for tuners, amps, or signal splitting
- -20 dB balanced output pad for hot signal management
Technical Highlights:
- Frequency response: 5Hz to 50kHz ±0.5dBu
- Max output: +22dBu at 1% THD+N
- SNR (Hi Z input): –83.5dB
- SNR (Reamp input): –101.71dB
- Input impedance: 1MΩ (Hi Z), 100KΩ balanced (Reamp)
- Output impedance: 150Ω balanced
LBDI and RBDI bring together DI, tube preamp, EQ, and reamp tools in one unit. They're suited for guitars, basses, synths, keys, and other Hi Z sources, offering hands-on control and authentic analog sound.