Manufacturing & Production

TELEFUNKEN Elektroakustik strives for perfection with manufacturing for all products. Not only should they perform and sound as best as possible, but also live up to the iconic TELEFUNKEN Elektroakustik name and the history it represents. The build quality of each product should be as pristine as each microphone sounds. For over a decade, the lab team has continuously improved their craft to the highest production quality standards. The tagline, "Built to a standard, not to a price," is far more than an advertising line; it is a company-wide mentality. Every step of production is performed to strict standards in both function and quality.

Each component has been selected for superior electronic properties and sonic quality and integrity. All film capacitors used in microphones are polystyrene film, the superior choice for transparency and performance in high fidelity audio circuits. They are custom-made and branded exclusively for TELEFUNKEN Elektroakustik in the USA. The electrolytic capacitors were selected through extensive technical and listening tests done with a wide variety of options to derive our component of choice. The Diamond Series features precision metal film resistors with a 0.1% tolerance, while R-F-T utilizes a still strict tolerance of 1%. All components have been chosen exclusively by sonic and electronic performance, never by price.

Prior to production, rigorous test procedures ensure the consistency and performance of each of the critical components in the microphone to the highest standard. The testing procedure includes the evaluation of every "new old stock" [NOS] vacuum tube for noise, gain, transconductance, and microphonics.

Capsules are evaluated for proper frequency response and sensitivity, while transformers are pre-tested for proper impedance, turns ratio, and frequency response. Once constructed, each complete system is burned-in and tested for overall frequency response, voltage measurements, noise, gain, phase shift, and most importantly, sonic character.


Few manufacturers can match the level of dedication and attention to detail given to the hand-built TELEFUNKEN Elektroakustik productsbefore they are ready to leave the building to TELEFUNKEN's dedicated and growing allegiance of users.


For Diamond Series manufacturing, absolutely no detail is left unattended. These microphones are meticulously built to historic specifications with no expense spared. Diamond Series products are genuine recreations of the increasingly rare microphones that have forged countless legendary recordings. With Diamond Series products, you can acquire this exact sonic quality coupled with perfected assembly techniques and improved circuitry.

From capsule to chassis to contacts, every part has been reverse engineered from vintage samples and a large collection of historic AKG, Neumann, and TELEFUNKEN documents. By developing these accurate recreations of the most sought-after microphones in the industry, TELEFUNKEN is able to offer nearly any replacement part for restoration of vintage models, providing a much-needed source for the vintage restoration market.

All Diamond Series products are hand-assembled from top to bottom. Each microphone is individually wired point-to-point; no circuit boards to be found here. Every plastic is riveted by hand, and each assembly is tapped and screwed together by hand. Diamond Series microphones are produced in smaller production runs to achieve the finest attention to detail.

Over the last decade, TELEFUNKEN has perfected the art of CK12 production to be more consistent and reliable than original AKG capsules. The TELEFUNKEN CK12 was developed by reverse engineering several generations of original AKG CK12 back plate configurations and selecting what we found to have the best overall response and performance. The back plates are both precision machined and hand-sanded to extremely tight tolerances, and each membrane is tensioned and tuned by hand. Through ongoing development and extensive research, TELEFUNKEN capsule engineers have achieved a higher consistency than ever thought before, taking all the guesswork out of the previously backbreaking process of exact capsule matching.

The ELA M 251 series and C12 both utilize the German-made Haufe T14/1 transformer, the original manufacturer for TELEFUNKEN GmbH of Germany. The U47 and U48 feature a proprietary American-made BV8 transformer, built to the same technical specifications as the original.

To complete the package, Diamond Series cables and power supplies are all hand-built in the TELEFUNKEN facility located in South Windsor, CT. Diamond Series cables feature original connector ends and high quality, quad-shielded tube microphone cable with superior RF rejection made in the USA by Accusound.

TELEFUNKEN Elektroakustik's premium power supplies feature the traditional styling of vintage Austrian and original Neumann NG models coupled with the improvements of modern component technology and circuit board design. Modern improvements include a slow-ramping filament voltage to extend vacuum tube life and full regulation to ensure your microphone will always operate the same, regardless of line voltage variations or location. Full regulation also means that stereo power supplies can also power only one microphone at a time at correct operating voltages.

Diamond Series power supplies are built on double-thick circuit boards for structural integrity and a PCB layout made to maximize current handling. These units are built well over-spec to ensure reliability and safe operation for decades. Each power supply is calibrated to the specific microphone system it comes with, and burned in as a full unit to ensure optimum performance and operation.


The R-F-T Series was developed to utilize elements of vintage designs and implement them in newly developed circuits. These microphones benefit from being able to draw inspiration from classic microphone designs, and having the freedom to tweak and modify them to suit design goals as needed without requiring historic accuracy. In order to offer microphones at a lower price point than the Diamond Series microphones, the R-F-T Series takes advantage of standardized metalwork from overseas as opposed to the Diamond Series' faithful dedication to historic construction. But don't be mistaken; the R-F-T microphones are 100% hand assembled from the ground up in CT, USA with the exact same level of attention to quality and performance as the Diamond Series.

The R-F-T line features all new old stock [NOS] vacuum tubes from manufacturers such as Telefunken GmbH, R-F-T, Raytheon, General Electric and Philips. These tubes are cleaned, burned-in, and tested for noise and microphonics prior to installation. The AR-51 and AR-70 utilizes the same Swiss-made Haufe T14/1 output transformer as in the ELA M 251 series and C12, while the AK-47 MkII uses a BV8 output transformer built to the original specifications as in the BV8 used in the U47. The CU-29 features a Lundahl LL1935 output transformer, which was selected as being the best sonic and electronic match to the 6AK5W-based amplifier circuit. The ELA M 260 microphones feature a custom American-made output transformer wound to match the output impedance of the amplifier circuit. All R-F-T capsules are individually tested in an anechoic chamber for proper frequency response and gain prior to installation into a microphone.

The R-F-T Series differentiates itself in its use of premium circuit boards for build efficiency, but these are no ordinary circuit boards. Instead of the modern day, mass produced boards with surface mount components and tiny traces, TELEFUNKEN has opted for hand plugging and soldering each board one at a time to ensure consistent quality. These circuit boards are precisely laid out with careful attention paid on directness and length of traces (especially for high-impedance lines) and maximum trace width for optimal current flow, which in turn closely emulates point-to-point wiring.

MANUFACTURING:  FET and Direct Boxes

The newest microphone in the TELEFUNKEN product line, and first foray into non-vacuum tube condensers, is the small diaphragm M60 FET microphone. The M60 FET features a custom American-made output transformer coupled with a unique circuit topology with a high-quality FET transistor by Linear Integrated Systems. This amplifier circuit is designed to be used with the same capsule set as the TEC Award-winning ELA M 260 vacuum tube condenser. The M60 FET utilizes all through-hole components hand soldered on a high-quality circuit board akin to the R-F-T Series. 

Components include Panasonic and Nichicon electrolytic capacitors, high quality polystyrene film capacitors, and an Amphenol connector. Each microphone is individually tuned for the lowest possible total harmonic distortion, and grouped as matched pairs for all stereo set configurations. The M60 FET is entirely hand-built from raw parts to completed microphone in our lab in South Windsor, CT, making it unique in the SDC market with how much attention to detail is given to the manufacturing process.

The direct box product line consists of four models: passive and active FET circuit designs, available in both mono and dual formats. The circuits are laid on high quality electroless nickel immersion gold (ENIG) circuit boards with all through hole components for a sturdier product than conventional surface mount technology. All direct boxes feature a rugged extruded aluminum chassis and aluminum inner panels. This simple yet optimal form factor allows the direct boxes to withstand the wear and tear of gigging use.

At the heart of all the direct boxes are custom-wound output transformer from OEP, part of the Carnhill Group, manufactured in the UK. The passive design features WIMA polypropylene and Nichicon MUSE Series capacitors, while the active design takes a queue from our M60 FET research and features a high-quality FET transistor from Linear Integrated Systems coupled with Nichicon MUSE and Fine Gold capacitors. All metal toggle switches and metal cased XLR and 1/4” connectors from Amphenol round out the robust construction of these DIs.

 Built entirely in Connecticut, the TELEFUNKEN direct box line provides users with a premium tool for both live and studio applications. These new manufacturing methods have helped evolve the lab team’s abilities to take on the growing product line of TELEFUNKEN Elektroakustik.