Focusrite Blue 330 Mastering Compressor/Limiter – RARE

Focusrite Blue 330 Mastering Compressor/Limiter – RARE
Focusrite’s Flagship Compressor 

The Blue 330, employing Focusrite’s unique single-VCA circuit design, offers unrivalled precision and performance in dynamic control in a mastering suite. All rotary controls are multi-position precision switches, allowing accurate recall of previous settings. Very accurate PPMs, switchable to measure gain change, input or output level, offer dual scale operation that allows accurate measurement of a wide range of peak signals. Thanks to the broad range of the threshold control and Focusrite’s proprietary circuitry, the Blue 330 can compress very high signal levels – up to +26dB without distortion. The Limiter too, offers an unusually wide threshold range. The VCA used is a balanced class A design, offering superb low noise distortion and excellent common-mode rejection. In order to separate compression and limiting, the sidechain electronics contain three VCAs to generate compression and limiting rather than the more common characteristic of compression that turns into limiting. The sidechain electronics utilise class A design techniques, ensuring superb transient response. Both compression and limiting therefore offer true peak response, not averaging RMS response and control.

The use of high quality audio Class A VCA as the only element between input and output means a very short signal path, and an ability to retain a natural, unobtrusive sound even when significant compression is being applied. LOOK AHEAD LIMITER Combines a low distortion Limiter with an audio delay to allow sidechain circuits a finite time to control and limit transients accurately. Designed to protect A/D convertors from fast transients, which would normally cause overload when connected through a standard limiter. Look ahead limiting allows more subtle limiting thresholds to be used while still protecting the A/D input from overload.

Features

• Power On/Off switch.
• Dynamics In switch: Turns on all dynamics sections. A quick press turns on the dynamics, another quick press turns off the dynamics. When held down the dynamics are turned on until released whereby the dynamics are turned off, this allows quick comparisons between compressed/limited and non compressed/ limited sounds.
• O/load indicator: Illuminates 6dBu below circuit overload takes place.
• Key switch: Feeds the sidechain signal from the external key input.

Make-up gain section:

• Make-up gain rotary switch: Applies gain from 0dB to 22dB in 1dB steps to both left and right channels.
• ±1dB vari potentiometer: Allows continuous adjustment of the make-up gain, when enabled.
• Vari in switch: Enables the use of the vari potentiometer.

Compressor section:

• High range: Shifts the operating threshold of the rotary threshold switch into a higher threshold range.
• Threshold rotary switch: Sets the level at which the compressor will start to compress the signal, low range – 26dB to -4dB, high range -6dB to +16dB.
• Ratio rotary switch: Sets the input to output compression ratio from 1.2:1 to 20:1.
• Attack rotary switch: Sets the attack time of the compressor from 300µs to 100ms.
• Release rotary switch: Sets the release time of the compressor 100ms to 4s or to auto which will vary depending on source material.
• Compressor In switch: Enables the compressor sidechain, the compressor becomes active when dynamics in switch is engaged.

Limiter section:

• Limiter In switch: Enables the lookahead limiter sidechain, the limiter becomes active when dynamics in switch is engaged.
• Threshold rotary switch: Sets the level at which the limiter will start to limit the signal, 0dB to 22dB.
• Limiter action indicator: Illuminates when the limiter is limiting the signal.

Input gain section:

• ±11dB rotary switch: Adjusts left and right input gain in 1dB steps.
• ±1dB vari potentiometer: Allows continuous adjustment of the input gain, when enabled.
• Vari in switch: Enables the use of the vari potentiometer.

Meter section:

• Peak program meters: These PPMs’ accurately display signal transients, low range -20dB to +4dB, high range -4dB to +20dB.
• +16dB switch: Changes the PPMs’ operating level to read in the high range.
• Input switch: Selects the input signal to be displayed on the meters.
• Key switch: Selects the key input signal to be displayed on the meters.
• Change switch: Selects the gain change to be displayed on the meters.
• Output switch: Selects the output signal to be displayed on the meters.