Helium


4-band Hybrid Equaliser

Helium combines capacitor based EQ circuits and filters with inductor based EQ circuits.
Helium is the child of Carbon and Iridium, with extra filter circuits added.

Helium is a full Class-A, discrete design, and all components have been carefully chosen and matched to provide an extremely musical sound.
This is definitely not a “clone” or “copy” (we at Interphase Audio do not build clones or copies of anything).
Like all our products, Helium is unique and features great sound and straight forward functionality.

The four bands have large overlapping frequency controls, making it well-suited for minimising problematic frequencies, or giving an extra boost to others.
The HF and LF band can be used as either bell-curved EQ or as - 12 dB per octave - hi—cut / lo-cut filter.
The two middle bands feature our inductive EQ, with custom-wound Carnhill inductors on the lo-mid band.

Each band can be cut or boost with as much as 15dB per band.

Helium is available as Octa module or as 500 module, with “Silver” or “Black” faceplate
Details on the difference between Octa and 500 modules, and why Octa modules are better, can be found at our our Octa page

Specifications

• Input impedance: 30kohm
• Common mode rejection: 80dB
• Distortion: 0.001% (+4dBu output, 1kHz)
• Frequency response: 7Hz to 70kHz (-3dB)
• Boost / Cut range: +/-15dB (continuously variable)
• HF Frequency: 1.2 kHz - 22 kHz (continuously variable)
• HF Frequency switchable to 12 dB per octave sweepable Hi-Cut filter 1.2 kHz - 22 kHz
• HMF Frequency: 1.5 - 3 - 5 - 6 - 7 - 8 kHz (stepped)
• LMF Frequency: 125 - 250 - 500 - 1k - 2k - 4k Hz (stepped)
• LF Frequency: 25 Hz - 440 Hz (continuously variable)
• LF Frequency switchable to 12 dB per octave sweepable Lo-Cut filter 25 Hz - 440 Hz
• Filter Q: 1.2 (just over 1 octave)
• Maximum input level (500 module): +28dBu
• Maximum input level (Octa module): +32dBu
• Maximum output level (500 module): +28dBu (10k load)
• Maximum output level (Octa module): +32dBu (10k load)
• Nominal input and output level: +4dBu (electronically balanced)
• Output impedance: 100 ohm
• Noise floor (typical, unweighted, EQ on): -80dBu
• Noise floor (unweighted, EQ off): -100dBu
• I/O connections (Rack XLRs): pin 2 +, pin 3 -, pin 1 ground
• Current requirement: 129mA (maximum) per rail
• Size and weight: Standard 500 Series, 0.7 kilos

What are Inductors ?

Inductors are wires wound around a coil that provide a form of frequency-dependant resistance. When they saturate, they bring out beautifully musical harmonics that give your tracks the silky-smooth, polished sound that has made classic consoles and equipment so desirable for over sixty years. This is what makes them different from capacitor-based EQ designs, which do a great job at surgical equalisation. But it has always been up to Inductors to provide the tone.

While some of the inductors we use are off-the-shelf, we also use custom inductors. This attention to detail in controlling variables such as the winding and core materials in relation to the surrounding circuitry allows our Inductor EQ’s to capture the classic sound, while at the same time be up to todays standards in sound-quality and noise level.

Helium - Hybrid EQ

Get yours from our order / buy page