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DB1      Professional Passive Direct Box



  • Floating Transformer-Balanced XLR Output for Maximum Isolation
  • SPKR Mode  Handles Amplifiers up to 600W RMS*
  • HI CUT Filter Reduces High Frequency Hiss
  • GND/LIFT Switch Eliminates Hum and Buzz
  • Flush-mounted Switches and Connectors Resist Damage
  • Passive Design Requires No Batteries or Phantom Power
  • Rugged ProCo Uni-Box Construction Provides Superior Protection and Shielding



The ProCo Model DB1 is a simple passive direct box that offers clean, reliable performance. It can be used for nearly any instrument or signal source, from electric bass, keyboards and drum machines to sub-mixers and external speaker outputs*. 

The DB1 preserves the “punch” and clarity of the sound that is often lost when mic’ ing a speaker, while eliminating the leakage, distortion and coloration. The signal delivered to the P.A. or studio mixer is crisp and clean - a vital element in retaining the full depth and brilliant sound of digital instruments such as synthesizers and digital drum machines.

The DB1 may be inserted into the signal path at virtually any stage required. For instance, a bass guitar signal can be “taken direct” from the instrument for a clean, natural tone, from a preamp or line output for a punchier or “equalized” sound, or from the speaker output of the amp if a dirtier “edge” is desired. For stereo or multi-channel applications such as Keyboards or digital drums we recomend the DB2 or DB4A.  The four-channel, rack-mountable DB4A Quad Direct Box is highly recommended for multi-channel applications. 

Built for the road, but equally at home in the recording studio, the DB1’s rugged 16-gauge steel and aluminum “Uni-box” enclosure is finished in a durable black texture powder coat finish with black anodized aluminum side channels. The uniquely slotted side channels allow for stacking on top or strapping side-to-side of virtually any number of ProCo TradeTools devices using the Uni-box construction. Easy to read control graphics are incorporated into the Lexan® top panel overlay.

*properly loaded speaker output.


All measurements made with 20 kΩ source feeding IN/OUT and 1.0 kΩ load on all LO-Z OUTPUT to simulate typical "real world" instrument pick-up and mic preamp. 0 dBv ref. = .775 volt.

Frequency Repsonse:
20 Hz - 20 kHz, ± 0.5% @ -15 dBv output.
-3 dB @ approximately 85 kHz.  
FILTER mode introduces 6 dB/octave attenuation above 4.0 kHz.

Total Harmonic Distortion:
<.03% 20 Hz - 20 kHz @ -30 dBv output.
<0.1% 30 Hz - 20 kHz @ -15 dBv output.
<.25% 20 Hz - 20 kHz @ -15 dBv output.

Phase Response:
<-18 degrees @ 20 kHz (ref. 1.0 kHz).

Rise Time:
<4.5 microseconds (2.0 kHz square wave, 10%-90%).

Voltage Stepdown:
<22 dB @ 1.0 kHz (INST mode).
SPKR mode attenuates signal by 20 dB.

Input Impedance:
>130 kΩ @ 1.0 kHz. (INST mode)
>105 kΩ @ 10kHz. (INST mode)
Nominal source impedance is 20 kΩ.
Approximately 8.2 kΩ (SPKR mode).
Nominal source impedance is 0 Ω.

Output Impedance:
<200 Ω @ 1.0 KHZ.
<215 Ω @ 10 kHz.
Nominal load impedance is >1.0 kΩ.

Maximum Input Level @ 50 Hz for 1% THD:
+16 dBv (INST), +34 dBv (SPKR) @ 20 Hz.
+21 dBv (INST), +41 dBv (SPKR) @ 30 Hz.
+26 dBv (INST), +46 dBv (SPKR) @ 50 Hz.