Tube-Tech HLT 2AM Mastering EQ  From Tube-Tech

The TUBE-TECH HLT 2AM is an all-new kind of Equalizer, combining High and Low shelving Eq plus Hi and Low cut filters with an innovative T filter “tilt” midrange Eq. It’s the first time this combination of filters has been designed in the analog domain.

The midrange T-Filter “tilts” the entire spectrum around a selectable midrange frequency point. Frequencies above that point increase (or decrease) while frequencies below that point decrease (or increase). This unique topology, provides a powerful and uniquely efficient way to get beautiful-sounding overall equalization. As such, the Tube-Tech HLT-2AM is destined to become a “go-to” equalizer in high-end mastering houses,smaller project studios, and everything in between.

Like all Tube-Tech processors, the stereo HLT-2A possesses a warmth and character that breathes life into a track and gives it an organic body that somehow manages to occupy real physical space inside a stereo mix.

However, the functionality of the HLT-2A is unique in the Tube-Tech line – and indeed in the world of analog processing. Users will find that the HLT-2A generates quick, intuitive results that can range from mild to extreme, and it sounds great on individual tracks or strapped across the drum bus or the mix bus.

Features and Technical Specifications

HLT 2A is a stereo unit, featuring active low and high shelving EQ and a passive T-filter plus passive Hi/Lo cut filters. The shelving EQ’s are designed around a high gain tube amplifier, and the T- filter and Hi/Lo filters are passive filters placed after the active shelving EQ and before the output amplifier. All sections are supplied with a bypass switch. The HLT2A furthermore features an overall bypass switch.

The low and high cut filters are also passive with a slope of 6dB/octave. A bypass switches the whole filter section out of the amplifier circuit, keeping the output stage in the circuit. The T-filter is like a seesaw. When the low end goes up, the high end goes down and visa versa.

When the potentiometer is turned clockwise, the high frequencies are boosted and the low frequencies are attenuated. When the potentiometer is turned counter clockwise, the low frequencies are boosted and the high frequencies are attenuated.

The unit is all tube based except for the power supply, input and output have fully floating transformers and all DC voltages are stabilized, except the anode voltage for the output stage.

- Tube based push-pull amplifier

- Freq. resp. @ -3 dB: 5 Hz – 55 kHz

- Low noise: < -80 dBU @ 0 dB gain

- CMRR: > 60 dB @ 10 kHz

- All-tube active/passive EQ

FILTERS:

- Low cut: 18, 25, 40, 60, 85 Hz, 6db/octave

- Low shelving: 18, 37, 80, 180, 370, 800 Hz. Gain: +/‑12dB

- High shelving: 1, 2, 5, 10, 15, 22 kHz Gain: +/‑12dB

- T.-filter: 0,5, 1, 2kHz. Gain: +4/-7 dB

- High cut: 12, 15, 18, 20, 25 kHz, 6db/octave

- Tracking between channels: +/-0,3 dB

- Input impedance: >10 kΩ

- Output impedance: < 60Ω

- Conductive plastic potentiometers

- In- and output are transformer balanced and fully floating

How Does It Sound?

The TUBE-TECH HLT 2A marks a different approach to EQ’ing. It is a very powerful overall shaping EQ, yet extremely simple to operate. Simply put, the HLT2A will yield good results for basically any material and application, ranging from the demanding mastering engineer to the sound quality hungry project studio owner. The combination of Hi and Lo shelf and Lo/Mid frequency T just creates a ton of very nice EQ shaping possibilities!

Description

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 designed around a high gain tube amplifier. The T-filter is a passive filter placed between the shelving filters and the output amplifier. All three sections are supplied with a in/out switch. The low and high cut filters are also passive with a slope of 6dB/octave.

A bypass switches the whole filter section out of the amplifier circuit, keeping the output stage in the circuit. The T-filter is like a seesaw. When the low end goes up, the high end goes down and visa versa. When the potentiometer is turned clockwise, the high frequencies are boosted and the low frequencies are attenuated. When the potentiometer is turned counter clockwise, the low frequencies are boosted and the high frequencies are attenuated.

The unit is all tube based except for the power supply. Input and output have fully floating transformers. All DC voltages are stabilized, except the anode voltage for the output stage. 

Mastering Version

A mastering version of the HLT2A with stepped pots and a smaller and more detailed range for the shelf and T- filter EQ is now shipping!