Tube-Tech HLT 2A Equaliser

The midrange T-Filter in the Tube-Tech HLT 2A “tilts” the frequency spectrum around a selectable midrange point. Above this point, frequencies increase or decrease, while below it, they shift in the opposite direction.

This unique design delivers an efficient and effective way to achieve beautifully balanced overall equalisation. The Tube-Tech HLT 2A is set to become a staple in high-end mastering studios, project studios, and everything in between.

As with all Tube-Tech equipment, the stereo Tube-Tech HLT-2A offers warmth and character, bringing an organic presence to any track and adding a sense of depth in stereo mixes. However, its functionality is distinct within the Tube-Tech range—and across the analogue processing world.

The Tube-Tech HLT 2A delivers intuitive results, whether mild or extreme, and performs excellently on individual tracks or across drum and mix busses.

The Tube-Tech HLT 2A is a stereo unit featuring active low and high shelving EQ, a passive T-filter, and passive high/low cut filters. Its shelving EQs are powered by a high-gain tube amplifier, while the T-filter and high/low cut filters are passive components positioned after the shelving EQ and before the output amplifier. Each section has a bypass switch, including an overall bypass for the entire unit.

The passive high and low-cut filters have a slope of 6dB per octave. A bypass switch removes the entire filter section from the amplifier circuit, leaving the output stage active. The T-filter operates like a seesaw: when the low end is raised, the high end is lowered, and vice versa.

Turning the potentiometer clockwise boosts high frequencies and attenuates low frequencies. Counterclockwise rotation boosts lows and reduces highs. The unit is fully tube-based except for the power supply, with fully floating transformers on input and output, and stabilised DC voltages, aside from the anode voltage in the output stage.

How Does It Sound?

The Tube-Tech HLT 2A brings a fresh approach to EQ. It’s an exceptionally powerful shaping tool that remains incredibly easy to use. In short, the HLT 2A works well across various materials and applications, making it a valuable asset for mastering engineers and project studio owners who prioritise sound quality. The combination of high and low shelves with a low/mid frequency T-filter offers a wide range of pleasing EQ shaping options.

The Tube-Tech HLT 2A is a stereo unit featuring low and high cut filters, low and high shelving filters, and a T-filter. The shelving filters are built around a high-gain tube amplifier, while the T-filter is a passive component placed between the shelving filters and the output amplifier.

Each section includes an in/out switch for added flexibility. The low and high cut filters are also passive, with a slope of 6dB per octave.

A bypass switch removes the entire filter section from the amplifier circuit, while keeping the output stage active. The T-filter operates like a seesaw: as the low-end increases, the high-end decreases, and vice versa. Turning the potentiometer clockwise boosts the high frequencies and reduces the lows; turning it counterclockwise boosts the lows and reduces the highs.

The unit is fully tube-based except for the power supply, with input and output featuring fully floating transformers. All DC voltages are stabilised, except for the anode voltage in the output stage.

Mastering Version

A mastering version of the Tube-Tech HLT 2A, featuring stepped potentiometers and a refined range for both the shelf and T-filter EQ, is now available!