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AV1B      Audio Visual Passive Direct Box



  • Better Sound from Computers and DVDs
  • Ideal for Meetings, Lectures and Presentations
  • Output is Transformer-isolated and includes a Ground/Lift Switch
  • Rugged "Uni-Box" Construction for Superior Protection and Shielding
  • Selectable Low-pass “Hiss” Filter
  • Offers Choice of Standard Connectors—No Adapters Needed
  • Properly Converts Signal Levels from -20 to +40 dBv


The ProCo TradeTools AV1B Audio-Visual Interface allows the line-level outputs of audio and video playback devices, etc., to be connected to microphone inputs of house or portable P.A. systems for programs in school auditoriums, lecture halls, civic meetings and corporate board rooms. The AV1B provides audio interfacing and isolation with wide response and low distortion.

Three different types of input connectors—1/4” (6.3mm) T/R/S phone, 2 RCA-type phono, and 3.5mm T/R/S mini jacks — simplify connection of most equipment. The PAD IN/OUT attenuator switch allows greater flexibility for handling line output sources at either “hi-fi” -10 dBV or “professional” +4dBm levels. The DBT-1 transformer provides a floating 150-ohm output with a standard 3-pin male XLRtype connector, so connection to most P.A. system mixers or mixer/amplifiers requires only a standard microphone cable. The GND/LFT switch eliminates hum and buzz from AC ground loops between equipment. For further versatility of operation, there is also a 1/4” (6.3mm) unbalanced line-level output.

The AV1B’s construction and components are top-grade throughout, ensuring trouble-free operation in educational, institutional and A/V rental settings. ProCo’s “Uni-box” enclosure is formed of extruded aluminum side channels and 16-gauge steel top, bottom and end plates and is designed to protect it’s switches and connectors from accidental damage. The use of steel also provides excellent magnetic shielding for the transformer from EMI/RFI fields. The finish is durable black textured powder coat on the end plates and the side channels are black anodized aluminum. Easily readable control and connector identification graphics are incorporated into a durable Lexan® overlay on the top panel. 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.



NOTE:  All measurements made with 0 ohm source feeding INPUT and 1.0 kohm load on MIC LEVEL OUTPUT to simulate typical "real world" projector and mic preamp. 0 dBv ref.=.775 volt

Frequency Repsonse:
20 Hz - 20 kHz, ± .5% @ -15 dBv output.
-3 dB @ approximately 85 kHz.

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

<.1% 30 Hz - 20 kHz @ -15 dBv output.
<.25% 20 Hz - 20 kHz @ -15 dBv output.

Voltage Loss:
<1.0 dB @ 1.0 kHz.
PAD CIRCUITS attenuate signal by 6dB, 12 dB and 18 dB

Input Impedance:
>130 kΩ @ 1.0 kHz (LO mode).

Approx. 82 kΩ (HI mode).

Output Impedance:
<200 Ω @ 1.0 kHz.

Nominal output impedance is >1.0 kΩ.

Maximum Input Level @50 HZ for 1% THD:
+26 dBv (PAD OUT mode) 
+46 dBv (PAD IN modes)