Intellijel Polaris

Overview

The Intellijel Polaris is a 4-stage cascaded OTA filter designed by David Dixon. It builds on the lineage of the Dr. Octature and Atlantis filters, but with a totally revised core and resonance control. Along with dedicated LP, HP and BP outputs, it features a configurable MULTI output capable of an unprecedented 27 different filter modes.

With drive turned down, the Polaris is capable of buttery smooth filtering, and the cutoff control range has been fine-tuned for playability. With the drive dialled up and the new asymmetric multi-distortion circuit engaged, it creates a more aggressive sound. Not content to be just a filter, the Polaris's AP phaser mode combined with frequency modulation can be used to achieve a phaser effect.

With so much versatility in a modest size, the Polaris is an ideal filter for a starter system and an excellent addition to the tonal palette of a larger modular.

Features

• Dedicated LP, BP and HP outputs.
• MULTI output with 27 selectable filter types: 4 x LP, 5x BP, 4 x HP, 5 x Notch, 4x AP and 4 x Phaser (AP mode with inverted dry blend).
• Input drive control with soft clipping distortion.
• MULTI output asymmetric distortion.

Installation

Intellijel Eurorack modules are designed to be used with a Eurorack-compatible case and power supply.

Before Your Start

Before installing a new module in your case, you must ensure your case's power supply has sufficient available capacity to power the module:

• Sum up the specified +12V current draw for all modules, including the new one. Do the same for the -12V and +5V current draw. The current draw will be specified in the manufacturer's technical specifications for each module.
• Compare each of the sums to the specifications for your case's power supply.
• Only proceed with installation if none of the values exceeds the power supply's specifications. Otherwise, you must remove modules to free up capacity or upgrade your power supply.

You will also need to ensure you have enough free space (hp) as well as free power headers in your case to fit the new module.

You can use a tool like ModularGrid to assist in your planning. Failure to adequately power your modules may result in damage to your modules or power supply. If you are unsure, please contact Intellijel before proceeding.

Installing Your Module

When installing or removing a module from your case, always turn off the power to the case and disconnect the power cable. Failure to do so may result in serious injury or equipment damage.

Ensure the 10-pin connector on the power cable is connected correctly to the module before proceeding. The red stripe on the cable must line up with the -12V pins on the module's power connector. The pins are indicated with the label -12V, a white stripe next to the connector, the words "red stripe", or some combination of those indicators.

A diagram shows a Eurorack power cable connected to a module's power header, with the red stripe indicated. Another diagram shows a Eurorack power supply with labeled pins, including -12V, +5V, +12V, and GND, and a red stripe indicator on the cable.

If you are using another manufacturer's power supply, check their documentation for instructions.

Once connected, the cabling between the module and power supply should resemble the picture below:

A diagram shows the correct ribbon cable connection between a module and a power supply.

Before reconnecting power and turning on your modular system, double-check that the ribbon cable is fully seated on both ends and that all the pins are correctly aligned. If the pins are misaligned in any direction or the ribbon is backwards, you can cause damage to your module, power supply, or other modules.

After you have confirmed all the connections, you can reconnect the power cable and turn on your modular system. You should immediately check that all your modules have powered on and are functioning correctly. If you notice any anomalies, turn your system off right away and check your cabling again for mistakes.

Front Panel

A diagram of the Intellijel Polaris front panel with numbered controls and inputs/outputs is provided.

• 1. MODE: Cycles through the different filter modes of the MULTI output. LEDs indicate the selected mode (LP, BP, HP, N, AP, PHASER).
• 2. TYPE: Cycles through filter types for the selected mode. Each mode has up to 5 variations.
• 3. CUTOFF: Sets the cutoff frequency of the filter. Combined with FM1 and FM2 inputs.
• 4. INPUT DRIVE: Sets the drive/amplification of the input signal. Unity gain is at 12 o'clock. Higher settings introduce clipped distortion.
• 5. Q: Sets the resonance of the filter. Combined with the Q input.
• 6. Q Attenuator: Attenuator for the Q CV input.
• 7. MULTI DISTORT: Engages the distortion circuit on the MULTI output when in the up position.
• 8. FM1: Controls the amount of attenuation of the FM1 input. Tracks 1V/Oct when fully clockwise.
• 9. FM2: Controls the amount and polarity of the FM2 input. Unmodified when fully clockwise, inverted when fully counter-clockwise, no effect at 12 o'clock.

Inputs & Outputs

• A. IN: Audio input to the filter.
• B. Q: CV input for the Q control. Attenuated by the black attenuator connected to the Q knob.
• C. FM1: CV input for the cutoff frequency. Attenuation controlled by the FM1 knob.
• D. FM2: CV input for the cutoff frequency. Attenuation controlled by the FM2 knob.
• E. LP: 4-pole (24 dB/oct) low pass filter output.
• F. BP: 2-pole (12 dB/oct) band pass filter output.
• G. HP: 4-pole (24 dB/oct) high pass filter output.
• H. MULTI: Configurable filter output, configured by MODE and TYPE buttons and processed through the distortion circuit if enabled.

Multi Modes

The MODE and TYPE buttons select the filtered signal available at the MULTI output. Pressing either button cycles through options, indicated by LEDs. For labels between two LEDs (e.g., BP and N), both surrounding LEDs will be lit. Not all modes have 5 filter types.

The module remembers the last selected type and mode when powered down.

Filter types are arranged such that the filter slope increases with each type. For example, LP mode A is a 1-pole low pass, B is a 2-pole, etc.

Trimmers

The side of the Polaris PCB has a resonance balance trimmer that can be used to set the balance of the self-resonating feedback of the filter with the input signal. This trimmer can be adjusted to change the sound of the filter when in self-resonance. Use a Phillips head screwdriver to set the balance to taste.

The position of the trimmer is highlighted in the photograph below:

A photograph shows the internal PCB of the Polaris module with a trimmer highlighted.

Technical Specifications