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Roswell Pro Audio Mini K47

Cardioid Condenser Microphone

The Mini K47 is a large-diaphragm condenser microphone that is unique due its capsule design, its component quality, and its origin.

As the microphone’s name states, the capsule is a 34mm K47 style, based on Neumann’s design. It is a true single-backplate capsule, with the characteristic K47 drilling pattern. The diaphragms are made of Dupont Teijan brand Mylar. The front diaphragm is metallized with gold.

The mic uses a linear, transformerless circuit based on the Schoeps design. It delivers relatively high sensitivity (18mV/Pa) and low self-noise (13dBA).

Early production runs of the Mini K47 used a 2SK30A JFET, which has relatively low input capacitance (CISS), which avoids the performance reduction (in sensitivity and signal-to-noise ratio) that is common to microphones employing the popular 2SK170 JFET. These mics used a polystyrene input coupling capacitor. Signal capacitors were genuine Wima parts, imported from Germany.

The mic’s internals were significantly upgraded in early 2021. The Hartley oscillator that creates polarization voltage for the capsule was replaced with a CMOS based implementation that has lower noise and is more stable. The audio circuit was revamped; 100% of the components were upgraded.

The input circuit was redesigned to omit the coupling capacitor. The JFET was upgraded to a vintage part that Roswell has not disclosed; these transistors are hand-selected to meet noise and distortion requirements. Signal capacitors are vintage European parts, hand-matched to better than 1%. Resistors are Vishay branded, 50ppm, 1% tolerance.

The body sleeve is made of heavy steel.

Each Mini K47 goes through a 7-point test/QC program, including a 24-hour burn-in, an acoustic frequency sweep, and tests for polarity, sensitivity, and noise. A serial numbered, signed QC card is included with each microphone.

Through the summer of 2017, the mic shipped with a swivel mount and an elastic shockmount. Beginning in September 2017, the microphone was upgraded in numerous ways:

• The microphone’s headroom was improved by several dB, to make it easier to use the mic on moderate to high SPL sources.
• A more durable metallic black sparkle finish was introduced.
• The shockmount was upgraded to the Cutaway™ mount from the higher-priced Delphos microphone.
• The mic began shipping in an aluminum flight case.

Sometime in 2018, the company began including a Roswell branded, custom made microfleece storage pouch / dust cover with every Mini K47.

The company also offers matched pairs of this mic; the match criteria is 0.3dB in sensitivity (measured at 1kHz), and 1.5dB in frequency response (50–15,000Hz).

Paul Vnuk, Recording Magazine

The Mini K47 is an impressive debut for Roswell Pro Audio. It is not just one of the best entry-level mics money can buy, it is also one of those workhorse mics that will find use in a mic locker forever, regardless of whatever other microphones one owns.

The Mini K47 was rated “Outstanding” by Professional Audio magazine for its price-to-value ratio. (The award predates the shockmount and case upgrades of late 2017.)

Permalink: Roswell Pro Audio Mini-K47

The mic was released in 2014.

Specifications

Pickup Patterns	Pads & Filters
Cardioid (18 mV/Pa; 20 - 16,000 Hz)

Capsule Dimensions	Impedance	SPL/Noise
Diaphragm diameter: 26mm Capsule diameter: 34mm Diaphragm gauge: 3 microns	200 Ohms (Low)	Self-noise: 13.0 dB(A)

Weight	Length	Max Diameter	Interface(s)
325g (11.46oz)	150mm (5.91'')	44mm (1.73'')	3-pin XLR male (1)

Power Specifications
Requires phantom power

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