Mystery Magicians LBDI Tube Instrument Preamp and Re-Amper Direct Box

The Mystery Magicians LBDI is a fully tube‑based, Class A desktop direct box and instrument pre‑amp that delivers up to 53 dB of gain, a three‑band tube EQ, a dedicated re‑amp input and a rugged lunch‑box chassis powered by NOS 12AU7 tubes running at 320 V.

Classic Tube Design Meets Modern Flexibility

The unit retains an all‑tube signal path, hand‑wound output transformers and vintage‑grade components such as WIMA, Panasonic and TRW capacitors, metal‑film resistors and Japanese TOCOS sealed potentiometers. Modern upgrades include a switchable high/low‑gain front end, a bright‑switch that adapts to input‑gain level, a –20 dB balanced output pad and a phase‑reverse switch. The integrated re‑amp input accepts line‑level sources, letting recorded tracks run through the tube circuitry for added harmonic richness. A front‑thru jack enables parallel routing to tuners or amplifiers, while a ground‑lift switch eliminates hum‑inducing loops.

High‑Impedance Input and Versatile Tone Shaping

The Hi‑Z input accommodates passive and active pickups, and the selectable gain stage lets the musician dial clean headroom or saturated warmth. Input and output gain knobs give precise control over the tube stages, while the true‑bypass three‑band EQ offers ±15 dB bass, ±6 dB mids and ±10 dB treble adjustments. The bright‑switch boosts high frequencies at low gain settings and tapers off as gain increases, preserving clarity without harshness. Together, the EQ and bright‑switch enable a Pultec‑style boost‑and‑cut technique for nuanced tonal sculpting.

Robust Build for Gigging Musicians

CNC‑machined anodised aluminium knobs and a dual‑tone hammertone powder‑coated steel chassis provide durability and a premium feel. A chromed handle turns the portable “lunch‑box” enclosure into a ready‑to‑carry rig, while the auto‑line‑detecting power supply supports worldwide voltages. Omron audio‑grade relays handle all signal switching, ensuring reliable operation on stage or in the studio.

Why Choose the Mystery Magicians LBDI

• Immediate access to classic tube warmth without the need for external boosters.
• Seamless integration of DI, pre‑amp, tone‑shaping and re‑amping in a single compact unit.
• Flexible gain architecture lets players move from pristine clean tones to rich saturation.
• Robust construction and global power compatibility suit touring professionals.

• Fully tube‑based, Class A desktop direct box and instrument pre‑amp
• Up to 53 dB of maximum gain
• Switchable high/low‑gain front end for pickup sensitivity
• True‑bypass three‑band tube EQ (±15 dB bass, ±6 dB mids, ±10 dB treble)
• Bright‑switch that adapts to input‑gain level
• Dedicated line‑level re‑amp input
• Phase‑reverse switch and –20 dB balanced output pad
• Ground‑lift switch to eliminate hum‑inducing loops
• Front‑thru jack for parallel routing to tuners or amps
• Hand‑wound output transformers built in‑house
• NOS Phillips ECG 12AU7 tubes operating at 320 V
• WIMA, Panasonic and TRW audio‑grade capacitors
• Metal‑film resistors and Japanese TOCOS sealed potentiometers
• Omron audio‑grade relays for reliable switching
• CNC‑machined anodised aluminium knobs and powder‑coated steel chassis
• Portable “lunch‑box” enclosure with chromed handle
• Auto‑line‑detecting universal power supply

This item, like everything we supply, comes with the complete support of our expert team. Our excellent technicians have been specifying, building and supporting studios for over twenty years. If you have any problems with installation, setup or everyday use, they’re never more than a click away, and always happy to help.

You can contact them here.