EQ901USB Equalizer - Digital Preamplifier - DAC for BOSE 901 Series I/II -III/IV or V-VI

The EQ901USB is also a high performance digital pre-amplifier (DAC) intended to drive high quality power amplifiers or integrated amplifiers/receivers.  Analog, USB and TOSLINK digital audio inputs are provided.

When used in the digital input mode the music stream is maintained in the digital domain all the way through the 901 equalization process.  This is the purest and highest fidelity way to drive your 901’s.

The EQ901USB Overview

• USB/TOSLINK Streaming Digital to Analog Converter (DAC) with built in equalization curves for the 901 Series V/VI

• Precise BOSE 901 equalization is performed digitally before the DAC in an Analog Device 400 MHz SHARC DSP processor with 24 bit resolution

• The four BOSE 901 tone modes (EQ curves) are available on all four outputs. Two identical stereo pairs outputs are available allowing for dual active stereo systems (two stereo power amps) or the addition of an active subwoofer(s)

• Remote selectable inputs:

1. Analog

2. TOSLINK

3. USB

• Remote selectable tonal characteristics settings:

1. Normal mode

2. Enhanced mode

3. Warm mode

4. Low frequency reduction mode

• Remote volume control with 0.5 dB resolution and mute

• Ultra low distortion 2 Vrms output driver stage

• Selectable input sensitivity of 2 Vrms or 4 Vrms

 What’s Included

• EQ901USB equalizer for your BOSE 901 Series I/II, III/IV or V/VI (select your series when ordering)

• Four precision engineered tone adjustment equalization curves

• Two identical stereo pairs outputs are available allowing for dual active stereo systems (two stereo power amps) or the addition of an active subwoofer(s)

• Deer Creek Audio USB drive with PC USB audio driver 

• IR Remote Control

• USB Cable

• US Regulated power supply - see option for global supply

Typical Connections

Stereo Mode

Dual Stereo (Quad) Mode

Active Subwoofer Mode

Tape/Processor Loop Set Up

IR Remote Control

Setting Tone Tone Characteristics Modes

Selection of the tone mode is generally a subjective choice based on what sounds best to you.  Specifically: Normal mode is the most neutral, Enhanced mode provides a richer sound with more treble and bass, Warm mode adds midrange with slight treble reduction, and Low frequency reduction mode is intended to control bass in smaller rooms or on boomy recordings .

Specifications

• EQ901USB platform base: miniDSP 2x4 HD

• Digital Signal Processor Engine: Analog Devices Fixed point DSP SHARC ADSP-21489

• USB controller: XMOS xCORE-200

• Digital to Analog Converter (DAC): AK4626A

• Internal Processing resolution & Sample rate: 32 bit / up to 192 kHz

• Audio Input Connectivity:  RCA, TOSLINK (optical), USB Audio

• Audio Output Connectivity:  Unbalanced output, RCA

• Input / Output Max Levels: In 2 Vrms / 4 Vrms (jumper-selectable), Out 2 Vrms

• Input Impedance: 10 k Ω

• Output Impedance: 560 Ω

• Filtering Technology: FIR + I/IIR

• Dimensions: 27 x 119 x 107 mm

• Power: 12V DC single supply, 2.1 mm round plug, 2.5 Watt

• IR Remote: miniDSP Remote

Warranty Terms

This product is warranted to be free from defects in materials and workmanship for a period of one year from the invoice date.  Warranty does not cover failure of the product due to incorrect connection or installation, improper or undocumented use, unauthorized servicing, modification or alteration of the unit in any way, or any usage outside of that recommended in this manual.  The customer provides return shipping to Deer Creek Audio. Deer Creek Audio is an Authorized miniDSP dealer.