United UT Tube67

United Studio Technologies UT Tube67 – Large-diaphragm tube condenser microphone

The UT Tube67 by United Studio Technologies is a faithful and deeply respectful homage to one of the most iconic and sought-after tube microphones in recording history. Since its introduction in the 1960s, this legendary design has shaped the sound of thousands of classic records, renowned for its velvety, creamy, full-bodied texture that has become an essential reference for vocals and acoustic instruments.

The UT Tube67 preserves the classic architecture of this iconic microphone and pushes it even further through premium component selection, uncompromising construction, and a modern artisan approach. The result is a tube microphone delivering timeless musicality with the reliability and consistency demanded by today’s studios.

At the heart of the UT Tube67 lies a genuine 1960s NOS EF86 pentode vacuum tube, carefully selected. Unlike modern dual-triode tubes, this pentode design delivers dense harmonic richness, natural depth in the low-midrange, and exceptional smoothness in the high frequencies. Vocals instantly gain intimacy, presence, and elegance, without harshness or excessive sibilance.

Thanks to a linear and coherent response across all polar patterns, the UT Tube67 excels not only on vocals, but also on strings, woodwinds, brass, piano, drums, and both acoustic and electric guitars. Its versatility makes it a microphone of choice for demanding recordings where true analog character is desired.

United has also included a switchable “Air” modification, favored by many classic recording engineers, allowing the top end to open up subtly for added detail and breath when needed.

Custom United UT K67 Capsule

The UT Tube67 is equipped with an exclusive UT K67 capsule, historically correct, featuring a dual backplate large-diaphragm design. Assembled in a laboratory clean-room environment, it uses a 6-micron Mylar diaphragm, 24k gold-sputtered, and is optimized for the microphone’s specific operating voltage.

Its tuning is based on an original 1970s capsule selected as a reference for its exceptional sonic character. This meticulous work results in a smooth, natural, and balanced sound, free from the artificial resonances often found in modern reproductions. The low and low-mid frequencies gain natural body, while the high end remains silky and controlled.

Custom United transformer and electronics

The UT Tube67 features a custom UT-BV12 transformer, wound in the USA to original historical specifications. High-nickel alloy laminations and a copper Faraday shield ensure tight, deep, and perfectly controlled low frequencies while drastically reducing RF interference.

The internal electronics are designed without compromise: maximum noise reduction, carefully selected discrete components, and full optimization of the signal path. The regulated external power supply provides stable, ultra-quiet voltage—essential for extracting the full performance of the NOS EF86 tube.

The included microphone cable is a Sommer Octave 7-conductor cable, made in Germany and widely regarded as one of the finest cables available for tube microphones, ensuring optimal signal transfer between the microphone and power supply.

From design to final assembly, each UT Tube67 is manufactured, calibrated, and tested in the USA. Built to last and deliver true boutique-level performance, it stands as a reference microphone for professional studios and demanding engineers seeking authentic, timeless tube sound.

Technical specifications:

• Type: Condenser microphone
  
  
• Capsule: UT Series, 34 mm brass, dual backplate K67 type
  
  
• Diaphragm: 6 micron, 24k gold-sputtered Mylar (PET)
  
  
• Capsule sensitivity: -38 dB @ 60 V
  
  
• Frequency response: 20 Hz – 20 kHz
  
  
• Polar patterns: Cardioid, Omnidirectional, Figure-of-8
  
  
• Maximum SPL: 137 dB @ 0.5% THD
  
  
• Output impedance: 38 Ω
  
  
• Amplification: Tube (vacuum tube)
  
  
• Tube: Selected NOS EF86 pentode
  
  
• Self-noise: < 11 dBA
  
  
• Transformer: Custom UT Series, made in USA
  
  
• High-pass filter: 80 Hz (-12 dB/oct.)
  
  
• Pad: -10 dB
  
  
• Body: Solid milled brass, nickel electroplated / satin black finish
  
  
• Mount: Shockmount suspension included
  
  
• Cable: Sommer Octave 7 conductor, 6 m
  
  
• Power supply: External, IEC320, switchable 110–120 V / 220–240 V
  
  
• Included accessories: Shockmount, dedicated power supply, 7-pin microphone cable
  
  

Key points:

• True vintage tube sound: NOS EF86 tube delivering warm, creamy, organic tone.
  
  
• Custom United K67 capsule: Tuned for natural smoothness with no harsh resonances.
  
  
• Three versatile polar patterns: Cardioid, omni, and figure-of-8 for any recording scenario.
  
  
• No-compromise audiophile components: Premium transformer, electronics, and power supply.
  
  
• Studio reference microphone: Vocals, acoustic instruments, ensembles, and critical recordings.