dbx DB10 - Passive Direct Box

dbx dB10 - Passive direct box with mu-metal transformer and high-cut filter

The dbx dB10 is a passive direct box designed to preserve signal integrity by converting an unbalanced Hi-Z output (guitar, bass, keyboards, recorders, etc.) to a balanced Lo-Z XLR output ready for long runs and mic preamps. A custom dbx transformer with mu-metal shielding provides galvanic isolation and low noise, while the gold-plated Neutrik XLR connector and high-quality metal switches ensure heavy-duty reliability. The dB10 features a switchable 0/20/40 dB pad to accept instrument and line level signals through to the speaker output , plus polarity inversion , ground lift , and a 6 kHz high-cut filter that emulates the cabling behavior of a power amp.

Beyond its rugged design (stackable chassis with rubber foot), the dbx dB10 delivers reference-grade audio performance : 20 Hz–20 kHz bandwidth ±0.1 dB (typ.) , 21 dB (typ.) insertion loss , THD+N ≤0.003% at 50 Hz, and a −120 dBu noise floor . All in a 100% passive design with no power required.

Main features

• Passive direct box with mu-metal shielded dbx transformer for isolation and low noise.
• Hi-Z 1/4" input and parallel THRU 1/4" output to feed your amp simultaneously.
• Balanced Lo-Z XLR output (Neutrik gold plated) suitable for mic preamps.
• Pad 0/20/40 dB : Supports instrument, line and speaker signals (with appropriate loading).
• 6 kHz High-Cut filter (active when the pad is at −40 dB) to soften the harshness of power amp takes.
• Invert (polarity) to adjust the phase relationship between the direct signal and the amp's microphone.
• Ground Lift to break ground loops and eliminate hum.
• Stackable chassis with rubber base, chrome switches and high-quality connectivity.

Product benefits

• Faithful and quiet sound : transformer isolation, excellent noise rejection and low distortion.
• True versatility in a single channel : from pedals and keyboards to amp speaker outputs (with the -40 dB pad and High-Cut filter).
• Professional integration : Balanced Lo-Z XLR for lossless long runs; THRU to maintain backline.
• Fast operation : three pads, filter, polarity and lift resolve phase, hum and harshness on the fly.

Use cases

• Guitar/Bass : Hi-Z input → XLR to mixer; use THRU to continue feeding the stage amp.
• From the amp's speaker output : Set the pad to −40 dB and activate the High-Cut (6 kHz). Always connect in parallel to a suitable speaker or load if your amp requires it.
• Keyboards and players : line level, balanced conversion for noise-free FOH/monitoring.
• DJ and varied backline : normalize impedances and avoid ground loops with Ground Lift.

Frequently Asked Questions

• How does it differ from the dB12 (active)? The dB10 is passive (no power required) and transformer-based; the dB12 adds active electronics and is ideal for very high-impedance sources/delicate passive pickups if maximum input linearity is desired.
• Can I connect it to the speaker output? Yes, with the pad set to −40 dB ; activate the High-Cut if you want a response more similar to miking a cabinet. Make sure the amp has the speaker load or load box specified by the manufacturer.
• What's polarity inversion for? It's used to align phase when you combine the DI with an amp mic or another direct input.

Description for projects

dbx dB10 Passive Direct Box ; Unbalanced 1/4" Hi-Z Input with Parallel 1/4" THRU ; Balanced Lo-Z (Neutrik) XLR Output; 0/20/40 dB Switchable Pad ; Active 6 kHz Low-Pass Filter with −40 dB Pad Only; Invert (Polarity) and Ground Lift ; Mu-Metal Shielded dbx Transformer; Performance (Typ.): 20 Hz–20 kHz Bandwidth ±0.1 dB , −3 dB Response <10 Hz–80 kHz , Phase +1° @ 20 Hz / −5° @ 20 kHz (2 kΩ Load), 21 dB Insertion Loss , 0.003% (50 Hz) THD+N , 0.002% (1 kHz/10 kHz) , −120 dBu Noise , 153 dB Dynamic Range ; Max. input levels: +20 dBu (0 dB) , +40 dBu (−20 dB) , +60 dBu (−40 dB) ; Input impedance (typ.): 0 dB load-dependent pad (e.g., 80 kΩ with 600 Ω at the output), −20 dB 65 kΩ , −40 dB 70 kΩ ; Output impedance ≈150 Ω (Lo-Z), max. output level 0 dBu ; Stackable chassis with rubber base; Dimensions 148 × 138 × 56 mm ; Weight 0.65 kg ; Passive (unpowered).