676 Tube Microphone Preamp Channel Strip


    Ships Directly from Manufacturer. Contact Us for Availability.

    dbx by HARMAN
    dbx by HARMAN
    The Pedigree of Professional Audio.

    At dbx Professional Products we are proud to introduce the all new 676 Tube Mic Pre Channel Strip. The 676 represents all of the best of dbx’s more than 40 years of dynamics processing.

    The 676 offers a pristine high-voltage, Class-A tube preamp section that runs on 250 volts, so your signal can be as crystal clean or dirty as you need it to be. The 676 also incorporates the compressor/limiter design from the highly-sought after dbx162SL, as well as a 3-band parametric EQ with sweepable mids.

    The 676 provides audio professionals with the perfect channel strip for recording and live applications alike with its military-grade build, vintage-inspired controls and VU metering.


    • Class-A Vacuum Tube Preamp with High Voltage Gain
    • High-Visibility Vintage VU Meter
    • Compressor designed from the dbx162SL
    • 3-Band Semi-Parametric EQ
    • 1/4” and XLR Inputs and Outputs
    • Front Panel Instrument Input
    • Side Chain Insert

    Mic Preamp Connector Female XLR Pin 2 Hot; Electronically balanced/unbalanced
    Mic Preamp Input Impedance 1.9 kO
    CMRR >85 dB from 20 Hz to 3 kHz, >70 dB from 3 kHz to 20 kHz
    Instrument Input Connector Tip-Sleeve ¼” Jack
    Input Type (instrument) Unbalanced
    Instrument Input Impedance 500 k O
    Max Input (instrument) +21dBu unbalanced
    Preamp Insert Connector Tip-Ring-Sleeve ¼”, RF filtered
    Preamp Insert Type Unbalanced, Tip = send, Ring = return
    Line Outputs (Preamp & Compressor/Limiter) Connector Male XLR and Tip-Ring-Sleeve ¼” (Pin 2 and Tip hot)
    Line Outputs (Preamp & Compressor/Limiter) Type Servo-balanced/unbalanced
    Line Outputs (Preamp & Compressor/Limiter) Impedance Balanced 30 O, unbalanced 15 O
    Line Outputs (Preamp & Compressor/Limiter) Maximum Output Level > +21 dBm (into a 600 ohm load)
    Compressor Sidechain Insert Connector Tip-Ring-Sleeve ¼”, RF filtered
    Compressor Sidechain Insert Type Unbalanced, Ring = output, Tip = input
    Compressor Sidechain Insert Impedance 1 kO (output), 50 kO (input)
    Vacuum Tube Type 12AU7A / ECC82
    Vacuum Tube Grid Power Supply +250V DC
    Vacuum Tube Heater Power Supply +12V DC
    Frequency Response (Mic Input) 20 Hz to 50 kHz, +0/-1dB, 40 dB gain
    Frequency Response (Instrument Input) 30 Hz to 70 kHz, +0/-1dB, unity gain
    THD + Noise (Mic In to LIne Out) 0.25% typical at 0 dBu out, 1 kHz, 40 dB gain
    THD + Noise (Instrument In to Line Out) 0.2% typical at 0 dBu out, 1kHz, unity gain
    Equivalent Noise Level Typically > -123 dBu with a 150 O source load, 22 Hz to 22 kHz
    Noise Floor Mic Insert to Comp Output: <-93 dBu, unity gain, EQ flat and no gain reduction
    Preamp Function Switches/Controls: Instrument Input Selects between microphone XLR input and front panel ¼” instrument input
    Preamp Function Switches/Controls: +48V Sends +48 VDC through 6.81 kO resistors to pins 2 and 3 of the microphone input
    Preamp Function Switches/Controls: 20dB Pad Attenuates the microphone input by 20 dB
    Preamp Function Switches/Controls: Polarity Invert Reverses pins 2 and 3 of the microphone input XLR
    Preamp Function Switches/Controls: 80 Hz Low Cut Enables an 80 Hz, 12 dB/octave high pass filter in the microphone and instrument signal path
    Preamp Function Switches/Controls: Gain Control Range -8 to +55 dB for Microphone Input; -8 to +40 dB for Instrument Input
    Preamp Function Switches/Controls: Post Tube Attenuation -8 to 0 dB
    Preamp Function Switches/Controls: Peak Indicator Illuminates RED when the Preamp is within 3 dB of clipping
    EQ Low Frequency 100 Hz, Low-pass shelving filter
    EQ High Frequency 10 kHz, High-pass shelving filter
    EQ Mid Frequency Sweepable from 100 Hz to 8 kHz
    EQ Function Switches/Controls: Narrow Selects the “Q” of the MID Frequency EQ. “OUT” position Q = 0.9; “IN” position Q = 2.9
    EQ Gain (All Bands) Sweepable from –15 to +15 dB
    Compressor Threshold Range -40 dBu to +20 dBu
    Compressor Threshold Characteristic Selectable OverEasy or Hard Knee
    Compressor Ratio Variable 1:1 to 8:1; 60 dB maximum Compression
    Compressor Attack/Release Modes Selectable Manual or Auto
    Compressor Manual Attack Time Scalable program-dependent; Typically 400 dB/msec to 1 dB/msec
    Compressor Manual Release Time Scalable program-dependent; Typically 4000 dB/sec to 10 dB/sec
    Compressor Auto Attack Time Program-dependent, typically 15 ms for 10 dB, 5 ms for 20 dB, 3 ms for 30 dB
    Compressor Auto Release Time Program-dependent, typically 120 dB/sec
    Compressor Output Level Control Range -20 dB to +20 dB
    Compressor Peak Indicator Illuminates RED when the Compressor/Limiter is within 3 dB of clipping
    Limiter Type dbx PeakPlus
    Limiter Threshold Range -4 dBu to + 22 dBu (off)
    Limiter Ratio 8:1
    Limiter Attack and Release Program-dependent
    Power Supply Universal switch-mode
    Operating Voltage 100 – 240 VAC, 50/60 Hz
    Power Requirements 20 Watts
    Fuse T2.5AL 250V
    Turn-On Time Approximately 2 seconds
    Dimensions 3.5”H X 19”W X 8”D (88.9mmH X 482.6mmW X 203.2mmD)
    Weight 8.1 lbs (3.7 kg)
    Shipping Weight 11.0 lbs (5.0 kg)
    More Information
    Manufacturerdbx by HARMAN
    Manufacturer Model Number676
    Manufacturer Part NumberDBX676FX
    Write Your Own Review
    You're reviewing:676 Tube Microphone Preamp Channel Strip