Focusrite OctoPre MkII Dynamic
Microphone Preamp, 8 Channel with Dynamics, ADAT I/O

With eight channels of Focusrite microphone pre-amplification, eight VCA-based Red 3-derived compressors and built-in 24-bit/96kHz digital inputs and outputs, OctoPre MkII Dynamic is Focusrite's feature-rich expansion upgrade for any digital audio workstation. It's equally an ideal expansion for any analogue or digital console, or hard disk recorder.

Digital inputs and outputs let you make the most of often-neglected ADAT I/O; ideal for expanding the number of mic pre inputs on your interface or for providing analogue monitoring from any digital ADAT feed.

With this entire package fitting into a single 1U chassis complementing Focusrite's Saffire PRO range, and all controls adjustable from the front fascia, OctoPre MkII Dynamic sets the standard for modern, compact, multi-channel recording expansions.

Saffire Mic Pre
Focusrite has, over the past two decades, built a reputation as the market leader for high quality recording equipment, with its mic pre technology as the cornerstone of the enviable reputation.

The original ISA mic pre, as featured in the early Focusrite Forte console, is still used by many of the industry's greatest producers and has contributed to the sound of countless hit records. Today, Focusrite designs equipment for a far greater audience, from professionals to amateur, all with varying budgets.

As with the Classic ISA mic pre used in both the ISA and Red ranges, the Saffire mic pre found in the OctoPre MkII Dynamic is designed to the highest possible standards. It upholds the same wide bandwidth philosophy featured in the original forte console, back in 1989. As with the Classic ISA mic pre, the Saffire mic pre design features custom components which have undergone an intense testing and qualification process.

With the facts and figures in, Focusrite designs then have to pass the essential listening stage. Any design can measure well on the test bench but only a great design can be qualified in the studio. The FET-based Saffire mic pre design is no exception. It delivers clarity without coloration and exhibits the signature transparency for which Focusrite have become famous.

With the high channel count interfaces (Saffire PRO 40 and Liquid Saffire 56) and both the OctoPre MkII and OctoPre MkII Dynamic, the Saffire pre-amp has been optimized for drums. The theoretical maximum level of a microphone was calculated, and the mic pre was adjusted with this in mind so as not to clip with this level present, set to minimum gian. As a result, the mic pre won't clip, even with a high output level mic right up close to a snare drum (the mic input will accept signal levels up to +16dBu from a microphone).

Compression
The Compressors featured in OctoPreMkII Dynamic are a new VCA-based, feed-forward design, derived from the celebrated Focusrite Red 3.

With just a single dial, these eight 'recording' compressors allow you to get to the desired amount of compression for each channel, fast, providing a natural but loud sound. The single dial solution decreases the threshold, and increases the makeup gain simultaneously, the result of which is a sound that gets progressively more compressed but retains a good output level.

The compressors use a soft-knee progressive compression curve, modeled on the properties of the Red 3 compressor, and featuring a fixed Attack time of 1.2 ms and Release time of 28ms. The circuit has been tuned by ear at Focusrite and these settings were chosen after critical listening and analysis of the Red 3. Bass guitar and drums were put through the Red 3 compressor, and the threshold, ratio, attack and release envelopes were modified until the desired 'controlled' sound was achieved. These settings were then applied to the new VCA circuit where the soft knee and ratio curve had been duplicated. A further listening then helped to tweak the settings and ensure that the compressors behaved as expected.

The compressor has two modes: Normal and 'More', which let you change the behavior of the compressor to suit different instruments. Whilst the Red 3 is well known and loved for its sympathetic approach to compression, it's not regarded as an 'effect' compressor. However, with the OctoPre MkII Dynamic's 'More' button, found on each compressor, you can bring a bit of aggression to your sound. The More button doubles the ratio from 2:1 to 4:1 and shifts the threshold range, so you have more sensitivity on control. The threshold is closed down, working across a smaller range, as you're applying threshold control over a much louder signal.

Features

• Eight award-winning Focusrite pre-amps
  Focusrite's unparalleled pre-amp legacy forms the foundation of this new device, with pre-amps optimized to handle extreme levels from sound sources like acoustic drums.
• Eight 'single-dial' Focusrite Compressors
  A single dial gets you to the right amount of compression, fast. These new VCA-based, feed-forward compressors model the character of the celebrated Focusrite Red 3.
• Compress transparently or with effect
  The classic soft-knee design achieves beautifully transparent compression that caresses your sound. Focusrite's unique "More" switch doubles the ratio to deliver 'compression with effect'.
• Built-in eight channel 24-bit/96kHz digital outputs
  Make the most of your interface's ADAT input for tracking, with eight channels of analogue to digital conversion via ADAT, boasting a 'real world' dynamic range performance of 110dB.
• Built-in eight channel 24-bit/96kHz digital inputs
  Switchable from the front panel, digital to analogue conversion via ADAT provides analogue monitoring of any digital ADAT feed, as well as the ability to clock from any ADAT device.
• State-of-the-art Clocking Solutions
  OctoPre MkII Dynamic's internal clock devliers a jitter performance of +/-20 PPM. For external clocks, industry-standard JetPLL jitter elimination technology is employed.
• Two high-quality instrument inputs
  OctoPre MkII Dynamic's first two channels feature DI's, ready for you to plug in your Guitars and Bass. No expensive external DI required.
• Input clip and Compression active LEDs on every channel
• 5 LED input metering on every channel
• Phantom power available on every channel (switched in two groups: 1-4 and 5-8)
• 24-bit resolution, 44.1, 48, 88.2 and 96kHz sampling rates
• Internal clocking, master clocking and external clocking via BNC or ADAT

Specifications

• Conversion
  A/D Dynamic Range 110dB 'A-weighted' (all inputs)
  D/A Dynamic Range 110dB 'A-weighted' (all outputs)
  Clock Jitter <250 pico seconds
  Sample Rates: 44.1kHz to 96kHz
  Sample Rate Clock Accuracy: +/-20PPM
  JetPLL technology providing superb jitter reduction for class leading converter performance
• Mic Input
  Frequency Response: 20Hz-20kHz +/-0.1dB
  THD+N: 0.001% (measured at 1kHz with a 20Hz/22kHz bandpass filter)
  Noise: EIN > 125dB (128dB analogue to digital): measured at ~60dB of gain with 150 ohm termination (20Hz/22kHz bandpass filter)
• Line Input
  Frequency Response: 20Hz-20kHz +/-0.1dB
  THD+N: <0.001% (measured with 0dBFS input and 22Hz/22kHz bandpass filter)
  Noise: -90dBu (22Hz/22kHz bandpass filter)
• Instrument Input
  Frequency Response: 20Hz-20kHz +/-0.1dB
  THD+N: 0.004% (measured with 0dBu input and 20Hz/22kHz bandpass filter)
  Noise: -87dBu (20Hz/22kHz bandpass filter)
• Analogue Outputs
  Frequency Response: 20Hz-20kHz +/-0.2dB
  THD+N <0.0010% (-100dB) (measured with 0dBFS input 22Hz/22kHz bandpass filter, un-weighted)
• Gain and Levels
  Mic Gain: +10dB to +55dB
  Line 1-8 Gain: -10dB to +36dB
  Instrument Gain: +10dB to +55dB
  Phantom Power switched in 4 channel groups on Mic. 1-4 and 5-8
  Mic and instrument maximum input level +16dBu
  Line maximum input level +26dBu
• Compression
  Threshold Range: -44dBFS (Max setting) to _4dBFS (Min setting)
  Compression Ratio Normal: 2:1, More 4:1
  Auto Make Up Gain: 4dB (Min setting), 18dB (Max setting)
  Attack Time: 1.2ms, Release time: 28ms (-3.5dB method)
  Compression Curve: Classic Focusrite Soft Knee
  THD+N (maximum at any compression threshold, input <+16dBu, gain at minimum): <-0.18%
• Clock Sources
  1. Internal clock
  2. Sync to Word Clock Input
  3. Sync to ADAT Input (ADAT 1 input only)
• Front Panel Indicators
  Metering of analogue inputs (channels 1-8), 5 segment (-42, -18, -6, -3 and 0dBFS)
  4 Sample Rate LED’s (44.1k, 48k, 88.2k & 96k).
  3 Sync Source LED’s (Internal, Word Clock and ADAT).
  ‘Lock’ Indicator LED.
  ADDA Switch for analogue output source selection (A/D’s or ADAT inputs).
• Dimensions
  Unboxed: W = 19”, H 1.8”, D 10.4”
  Boxed: W = 23.5”, H = 4.75”, D = 13.4”
• Weights
  Single unit unboxed net weight: 7.3 lbs
  Single unit boxed net weight: 8.9 lbs

Connectivity

• Analogue Inputs
  Mic / Line inputs on XLR Combo with auto-switching between Mic (XLR) and Line / Instrument (TRS).
  Mic / Line / Instrument 1 & 2: 2 x XLR Combo on rear panel.
  Mic / Line 3-8: 6 x XLR Combo.
  Instrument: As above, switched to Instrument (inputs 1 & 2 only).
• Analogue Outputs
  Line level 8 x ¼” TRS Jack.
  Nominal output level 0dBFS = 16dBu, balanced
  Switching to enable monitoring of A/D inputs or ADAT inputs with ADDA switch.
• Digital I/O
  ADAT Out 1 & 2: 8 channels (44.1 / 48kHz), 4 channels S-MUX (88.2 / 96kHz, 8 channels total).
  ADAT In 1 & 2: 8 channels (44.1 / 48kHz, ADAT 1 only), 4 channels S-MUX (88.2 / 96kHz, 8 channels total).