Description

Two classic tube microphone designs come together in the United Studio Technologies UT Twin48 large-diaphragm tube condenser microphone, offering distinct tonal characteristics and pickup patterns within a single recording tool. Inspired by revered German microphones of the late 1940s and 1950s, the UT Twin48 features selectable 47 and 48 operating modes, each with its own cardioid response and secondary polar pattern. A selected NOS EF86 pentode vacuum tube, custom United K48 capsule and American-made UT-BV8 output transformer form the foundation of its rich, full-bodied sound. The 47 mode provides a more open, detailed presentation, while the 48 mode offers a warmer, more intimate character. With four selectable pickup configurations, a dedicated discrete power supply and carefully selected components, the UT Twin48 gives engineers and producers flexible options for capturing vocals, acoustic instruments, brass, piano and room ambience.

Two Classic Cardioid Designs in One Microphone

The UT Twin48 recreates the distinct operating principles of two historic tube microphone designs rather than simply switching between conventional polar patterns. In 47 mode, the rear diaphragm is decoupled to create a true cardioid response with greater sensitivity and a more open presentation of background and high-frequency detail. Switching to 48 mode activates a different cardioid configuration, polarizing the rear diaphragm at the same voltage as the backplate for a warmer, more focused sound with slightly lower sensitivity. Each mode also provides a second pickup pattern: omnidirectional in 47 mode and figure-8 in 48 mode. These configurations allow engineers to explore different tonal perspectives and recording techniques without changing microphones.

Custom K48 Capsule and NOS EF86 Tube Circuit

A custom United K48 capsule provides the foundation for the UT Twin48's vintage-inspired response. Based on a historically accurate single-backplate, dual-diaphragm design, the 34 mm capsule uses 6-micron Mylar diaphragms with 24k gold sputtering and is optimized for 60V operation. Its carefully tuned construction works alongside a selected NOS EF86 pentode vacuum tube, whose harmonic characteristics contribute to the microphone's substantial, detailed tube sound. The custom-wound UT-BV8 output transformer follows historical Braunbuch specifications and uses high-nickel alloy laminations, while a copper Faraday shield helps reduce radio-frequency interference. Together, these components support the smooth high-frequency response and full-bodied character central to the microphone's design.

Discrete Power Supply and Professional Studio Construction

The UT Twin48 includes a fully discrete external power supply with independently regulated filament, B+ and polarization voltage rails. A custom Sparkos Laboratories filament regulator, discrete high-voltage regulation and an inline EMI/RFI input filter contribute to stable operation, while a selectable RF filter on the audio output provides additional interference control. The microphone connects through a custom 6m Sommer Octave seven-conductor cable and features a solid milled-brass body with nickel electroplating. An included suspension shockmount and custom-fitted vintage-inspired briefcase accommodate the microphone and its accessories. With final assembly and testing conducted in the United States, the United Studio Technologies UT Twin48 tube condenser microphone brings two distinctive vintage recording approaches into one versatile studio design.

United Studio Technologies UT Twin48 Large-Diaphragm Tube Condenser Microphone
United Studio Technologies UT Twin48 Large-Diaphragm Tube Condenser Microphone
United Studio Technologies UT Twin48 Large-Diaphragm Tube Condenser Microphone

Features

  • Large-diaphragm tube condenser microphone with dual 47 and 48 operating modes
  • 47 mode offers true cardioid and omnidirectional polar patterns
  • 48 mode offers active cardioid and figure-8 polar patterns
  • Distinct cardioid configurations provide two tonal characteristics
  • Custom United K48 capsule with dual 6-micron Mylar diaphragms
  • 34 mm capsule with 24k gold sputtering and single backplate
  • Selected NOS EF86 pentode vacuum tube
  • Custom-wound American-made UT-BV8 output transformer
  • High-nickel transformer laminations and copper Faraday shield
  • 20Hz–20kHz frequency response and 137dB maximum SPL
  • Fully discrete external power supply with selectable RF filtering
  • Includes Sommer cable, suspension shockmount and fitted briefcase

Specs

General
  • Product type: Large-diaphragm tube condenser microphone
  • Model: UT Twin48
  • Color: Nickel
Capsule and Construction
  • Capsule: United UT Series K48
  • Capsule diameter: 34 mm
  • Capsule design: Dual diaphragm, single backplate
  • Diaphragm material: 6-micron Mylar, 24k gold sputtered
  • Body material: Solid milled brass
  • Body finish: Nickel electroplating
Electronics
  • Amplifier type: Vacuum tube
  • Vacuum tube: NOS EF86 pentode
  • Output transformer: Custom-wound United UT-BV8
  • Transformer laminations: High-nickel alloy
  • Transformer shielding: Copper Faraday shield
Audio Performance
  • Operating modes: 47 and 48
  • 47 mode polar patterns: Cardioid, omnidirectional
  • 48 mode polar patterns: Cardioid, figure-8
  • Frequency response: 20Hz–20kHz
  • Maximum SPL: 137dB at 0.5% THD
  • Self-noise: 11dBA
  • Output impedance: 35 ohm
Controls
  • Operating mode selection: 47/48
  • RF output filter: Selectable
Connectivity
  • Audio output: 3-pin XLR, 24k gold-plated
  • Output wiring: Pin 2 hot, pin 1 ground
  • Microphone cable: Custom Sommer 7-conductor XLR, 6m
Power
  • Power supply: External discrete regulated power supply
  • Voltage regulation: Independent filament, B+ and polarization rails
  • Filament regulator: Sparkos Laboratories discrete regulator
  • AC input: 110–120VAC or 220–240VAC, switch-selectable
  • Power connector: IEC320 3-conductor receptacle
  • EMI/RFI input filter: Yes
Dimensions and Weight
  • Microphone height: 10"
  • Microphone diameter: 2.5"
  • Shockmount depth: 6"
  • Power supply width: 7.5"
  • Power supply depth: 7"
  • Power supply height: 3.25"
  • Briefcase width: 19.75"
  • Briefcase depth: 12.75"
  • Briefcase height: 6.75"
Included Accessories
  • Accessories: Discrete power supply, Sommer Octave 7-conductor cable, suspension shockmount, fitted briefcase

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