The UT Twin48 is an exceptional preservation of two venerable classic tube microphone designs. The original classics of the late '40s and '50s have been front and center in countless recordings — and demand for them is higher than ever! United has taken these classic-specification designs to the next level by uniting both designs into a single microphone.

Massive tube sound calls for the right tube: The UT Twin48's amplifier stage is based around a select new old stock EF86 pentode glass vacuum tube — the last living descendent of the originals' tube. This results in a bold, rich sound, due to the pentode's harmonic profile being much different than modern dual-triode tubes.

Twin Mode Operation

The classic 47 and 48-style mics each derived their cardioid operation in very different ways — producing subtle tone differences as well as a slightly different polar pattern. For the first time ever, the UT Twin48 delivers both options in a single microphone.

47 Mode offers both 47 Cardioid and Omni patterns, while 48 Mode offers 48 Cardioid and Figure-of-8. Each cardioid mode delivers a different tonal flavor and performance:

• 47 Cardioid: de-couples the rear diaphragm in a process known as True Cardioid, for a louder sound with improved sensitivity with more background and top-end detail.
• 48 Cardioid: polarizes the rear diaphragm with the same voltage as the backplate — AKA Active Cardioid — for a more tightly closed-in, warmer, intimate tone that is a bit lower in sensitivity.

Custom United UT K48 Capsule

The UT K48 capsule is a custom-made, historically correct single backplate/dual diaphragm capsule; skinned in a laboratory clean-room environment and 24k gold-sputtered on 6 micron Mylar. It's been optimized for 60v operation, and tuned to the exacting specifications of the original to match its ancestors' historically smooth sound while avoiding any resonances or overly bright or sibilant sounds that can be found in many other reproductions.

Custom United Transfromers

The custom-wound, US-made, UT-BV8 transformer is wound to the original Braunbuch specifications and set to the same laminations historically used on the original parts. Careful measurements were made from a golden specimen of the original German transformer.

High-Performance Power Supply

United Studios developed a fully discrete power supply with individually isolated discrete rails for filament, B+, and polarization voltages. They used a custom, US-made discrete regulator by Sparkos Laboratories for the filament voltage, and fully discrete Zener diode regulation for the high voltage rails, for clean, maintenance-free operation. (No calibration required — ever!) Custom US-made PRP resistors and long life/high quality electrolytic capacitors are used throughout, and very robust, over-spec'd, traditional linear frame-mounted power supply transformer.

In an effort to eliminate as much noise as possible, no IC package regulators, generic parts, or cheaper, switch-mode power transformers were used in the UT Twin48. The power supply also features both an inline EMI/RFI AC input filter as well as a selectable RF filter on the audio output, which can be engaged from the convenience of the power supply front panel.

It's not just another mic — it's a United.

The UT Twin48 is an exceptional microphone fit to be the showpiece of any studio and it provides boutique-quality sound that's built to last. Vintage-inspired briefcase is also included — custom-fit to house the UT Twin48 and all included accessories.