Tube-Tech HLT2AM Mastering Equalizer

The Tube-Tech HLT2AM Mastering Equalizer is the mastering version of the HLT2A and a totally new kind of analog equalizer that combines variable high and low shelving eq and filters with an adjustable midrange T-Filter.

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 HLT2AM 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 HLT2AM 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 HLT2AM is unique in the Tube-Tech line - and indeed in the world of analog processing. Users will find that the HLT2AM 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."

Tube-Tech HLT2AM Mastering Equalizer 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.

Tube-Tech HLT2AM Mastering Equalizer Features

• Stepped Pots
• Smaller and more detailed range for the shelf
• T- filter EQ
• LOW CUT
  • There are choices of five frequencies: 18, 25, 40, 60, 85 Hz and an off position. The slope of the filter is 6dB/octave
• LOW SHELVING
  • +/- dB: The gain control is continuously variable from +12dB to -12 dB.
  • Freq. Hz: There are choices of six frequencies: 18, 37, 80, 180, 370 and 800 Hz.
  • The frequency is where the boost or cut is 9 dB when the gain is at max.
• LOW SHELVING/OUT
  • Switches the GAIN in or out, resetting the gain to 0 dB.
• HIGH SHELVING
  • +/- dB: The gain control is continuously variable from +12 dB to -12 dB.
  • FREQ. kHz: There are a choice of six frequencies: 1, 2, 5, 10, 15, 22 kHz.
  • The frequency is where the boost or cut is 9 dB when the gain is at max.
• HIGH SHELVING/OUT
  • Switches the GAIN in or out, resetting the gain to 0 dB.
• T- filter
  • +/- dB: A 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 amount of boost is +4 db and the attenuation is -7 dB
  • Center Freq. kHz: There is three centre frequencies of the filter: 0,5- 1- 2 kHz.
• HIGH CUT
  • High Cut kHz: There are choices of five frequencies 12, 15, 18, 20, 25 kHz and an off position.
  • The slope of the filter is 6dB/octave
• T_FILTER - HIGH CUT /OUT
  • Switches the T-filter and the High cut filter in or out, resetting the gain to 0 dB.
• BYPASS
  • IN /OUT: The switch bypasses the whole filter section, leaving only the amplifiers in the circuit

Tube-Tech HLT2AM Mastering Equalizer Specifications

• 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

Tube-Tech HLT2AM Mastering Equalizer Includes

• Tube-Tech HLT2AM High/Low Shelving EQ (Mastering Version)
• IEC Power cable
• Manual