- 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
Overview
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.
Features
Specifications
| Mic Preamp Connector | Female XLR Pin 2 Hot; Electronically balanced/unbalanced |
| Mic Preamp Input Impedance | 1.9 kΩ |
| 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 Ω |
| 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 Ω, unbalanced 15 Ω |
| 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 kΩ (output), 50 kΩ (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 Ω 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 kΩ 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 | -∞ to +55 dB for Microphone Input; -∞ to +40 dB for Instrument Input |
| Preamp Function Switches/Controls: Post Tube Attenuation | -∞ 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 ∞: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 | ∞: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) |
