Twin Circuit Topology for the UT Twin87

The UT Twin87 captures the sound of two legendary “87-style” microphone generations in one design. To make that possible, United carefully studied component values, part types, and circuit differences across prized early-production and later-revision reference microphones. Those findings were then translated into two distinct circuit topologies.

This isn’t a simple EQ contour or digital imitation. With the UT Twin87, you’re switching between two authentic “87-style” circuit designs, representing nearly half a century of evolution.

Vintage Mode

In Vintage mode, the UT Twin87 uses phantom power voltage to polarize the capsule directly, just as the earliest microphones of this type did. This is made possible by its insulated dual-backplate capsule design. The high-impedance and de-emphasis stages also use component choices modeled after the originals.

The result is a sound that feels slightly warmer, softer, and more forgiving.

Modern Mode

In Modern mode, the capsule is polarized at a higher voltage using an FET oscillator circuit, as found in later revisions of the classic microphone. This increases capsule sensitivity and drives a hotter signal into the amplifier stage. The high-impedance and de-emphasis circuitry also reflect later-generation designs.

The result is a louder sound with a brighter, more articulate character, plus extended high-end reach and a more forward presentation.

Custom United UT-K87 Capsule

The UT Twin87 features United’s custom-built K87-style dual-diaphragm, dual-backplate capsule. We precision mill the UT-K87 from brass, fit it with 6-micron Japanese PET film, and finish it with a 24k gold-sputtered membrane. Technicians assemble each capsule in a laboratory clean-room environment to ensure maximum consistency.

In Vintage mode, the capsule is polarized directly from standard phantom power (+48V, ideally), while the front and rear diaphragms are polarized separately by the insulated backplate design. In Modern mode, the backplates are connected and the polarization voltage is gently boosted to approximately 63V using a specially designed circuit.

Custom United Transformers

United studied multiple versions of the original German output transformer used in this microphone family, drawing particular inspiration from larger vintage designs. Rather than compromise with a smaller or less substantial component, United therefore developed a custom-wound transformer. As a result, it features nearly four times the metal mass found in many competing ’87-style’ microphones.

The result is a transformer with no weak link in the signal path—preserving detail as the signal leaves the microphone and travels through long cable runs. The sound is open, spacious, and clear, with strong headroom and excellent low-end performance.

United prioritized performance over cost when they equipped their U.S.-made custom-wound transformer with large all-nickel laminations.

It’s not just another microphone. It’s a United.

Flexible Filtering and True Cardioid Mode

Many modern ’87-style’ microphones include an output filter designed to block RF and EM interference, though engineers have long debated whether that filter improves or affects the sound. However, with the UT Twin87, you make that choice: consequently, you can engage or bypass the filter at any time, in either Vintage or Modern mode.

When set to cardioid, the UT Twin87 also activates a true-cardioid modification. Instead of using a switched active cardioid circuit, it disengages the pattern-select circuitry entirely and decouples the rear diaphragm. The result is a slightly hotter, cleaner cardioid signal with improved signal-to-noise performance.

A Truly Versatile Studio Workhorse

With premium components and exceptional flexibility, the UT Twin87 delivers outstanding results across a wide range of applications. Its real strength lies in its accuracy—faithfully capturing the character of every major “87-style” variation.

Features of the UT Twin87

• Switchable Modern/Vintage circuit topology, not just a tonal preset
• Custom United 24k gold-sputtered K87-style dual-diaphragm, dual-backplate capsule
• Custom-wound, American-made United transformer with 4x the iron mass of many competing “87-style” microphones
• Switchable RF filter for added flexibility across classic and modern voicings
• Built-in true-cardioid modification for a cleaner, hotter cardioid response
• Professional-grade studio and voiceover workhorse with low noise, high headroom, and wide dynamic range
• Clean, clear, articulate, and open sound

Don’t forget to take a look at our other United Studio Technologies products!

Visit the United Technologies website for more info.