Microphones from DPA Microphones A/S
Lev Orlov

The DPA Microphones Company (the former Danish Pro Audio, DPA) was established in 1992 by Morton Stöv and Ole Brösted Sorensen, the leading engineers of the famous Bruel & Kjaer Co. and is engaged in development, marketing and servicing of professional microphones, which capsule manufacturing technology originates from the B&K 4000 series featuring outstanding sound quality.

At manufacturing microphone capsules, the DPA Microphones applies a number of knows-hows owing to which the sound reproduction quality of each and every microphone remains at a level unbeatable for other manufacturers.

For example, the preliminary high-voltage polarization process of condenser microphone cap increases the gap between the movable diaphragm and the stationary back-plate thus increasing load capacity and practically eliminating the possibility of audible distortion build-up, even when working with a sound-source featuring an extremely high volume level. For the entire disclosure of this method's potential, high-voltage power supplies are required. Taking into account that in most cases in studio every-day practice 48 V phantom power voltage is used, the DPA Microphones releases some models in pairs: to be powered by high-voltage preamplifiers and by usual phantom power sources.

High-voltage powering, preamplification and connection of the Bruel & Kjaer high-voltage microphone models to audio equipment are provided via the two-channel microphone preamplifier HMA 4000. It offers high load capacity and pre/post attenuation switching capability that, in turn, allows to use the microphones/preamp set to perform high-quality stereo recordings immediately with either analogue or digital recorders. The preamp output stage features two electronically balanced grounded outputs; it has an extremely low self-noise level and dynamic range of 140 dB. And as for the HMA 4000's frequency range, it is simply beyond words: 10 to 20000 Hz with ±0.5 dB irregularity. To avoid the possibility of damage for ordinary microphones when connecting them to this high-voltage power source, the HMA 4000's inputs have special seven-contact connectors installed. By means of a special adaptor, the HTP 4000, high voltage may be converted to standard +48 V, which allows the preamplifier to be used with microphones meant for standard phantom power. The PCC 4000 adaptor provides for the DPA microphones intended for high-voltage power supply to be connected to standard +48 V phantom power sources.

As for using small-diameter diaphragms in condenser microphones, it may give some additional advantages, e.g. capability to handle and withstand comparatively higher sound pressure levels, as well as ideal directivity characteristics across the entire frequency range. Both the application of exceptionally high-quality components and tight quality control at manufacturing microphone capsules guarantee stability in operation and very small dispersion of parameters. For instance, phase characteristics for an arbitrarily chosen couple of such microphone models differ not more than by 5 to 10% . At the very same time, for specially selected microphone pairs this phase dispersion equals 10% (ranging from 50 to 20000 Hz), and dispersion for other parameters - not more than 0.5%.

Each copy of the DPA microphone comes complete with an adjustment-graduating table that includes the results for individual measurements of frequency response with respect to the directivity, sensitivity, A-weighed equivalent noise level axes and other important information.

Compact microphones

In these models, like in usual DPA microphones of the corresponding price category, the same capsule type is used, although they are preamplified by a built-in ultra-small thin film FET-preamplifier. Thanks to their small size, they may be easily hidden out of a viewer's sight that, consequently, determines their application area. They may be powered by a standard +48 V power supply unit.

DPA 4021/4022/4023/4025 microphones

Besides audio characteristics, the microphones within the same model group have different ways of cable connection. The first modification: the cable is mounted at 90° from the directivity axis and the microphones are attached immediately to string or wind instruments with various mounts (available optionally). The second modification: the cable is mounted along the directivity axis; such microphone can be hanged up directly by the cable or mounted on a compact stand. The third modification: the cable with a LEMO-type connector ensuring compact yet reliable connection with a usual microphone cable.

DPA 4021/4022/4023/4025

Axis and off-axis amplitude-frequency diagrams of 4021, 4022 and 4023 microphone measured at distance of 30 cm from sound source

DPA 4033/4036/4037

DPA 4033/4036/4037

DPA 4051/4052/4053

DPA 4051/4052/4053

Technical characteristics of the DPA compact microphones:

Lavaliere (clip-on) microphones

A set of lavaliere condenser microphones of the DPA Microphones company on the basis of a 5.4 mm diameter capsule represents an absolutely newly tailored design pattern: the diaphragm is placed vertically ensuring omnidirectional frequency-independent pick-up diagram. The connection interface of the DPA lavaliere microphones is specially designed for use with professional UHF-band wireless systems of any make: Sennheiser, Bayerdynamic, AKG, Sony, Samson, Shure, Vega, Micron, Pastega, Audio Ltd., and others. This compatibility is achievable thanks to connecting adapters.

DPA 4060/4061/4062

The models are identical concerning their designs and acoustic parameters. Each model is available in three versions: with black, beige or white finish.

The interchangeable on-screwable plastic cartridges with protective grids of different sizes are the design elements not only protecting the capsule against wind, mud and high humidity, but also providing acoustic modification for the microphone according to its placement on the talent's body. The shortened protection grid gives neutral sounding with a gently sloping edged rise of the response at frequencies ranging from 8 to 20000 Hz (3 dB) and is used when mounting the microphone close to the talent's mouth. At clip-miking, the long grid, providing a steeper rise around 12 kHz (10 dB), is used. Such techniques do not require additional equalization by means of electronics and, accordingly, the self-noise level of the microphones remains invariably low.

For connecting to sound equipment including phantom power sources, a number of miniature adapters is available. In addition, the set of five-color foam windscreens for both wind protection & fast and easy visual identification is optionally available.

DPA 4065

This miniature microphone with a headband, concerning its acoustic parameters, is identical with the 4061 model. The sensitivity is 6 mV/Pa to match both the level of the human voice and the general input sensitivity of most wireless transmitters. The left- or right-side band is easily bent to fit any head shape in a tight fixed position to provide maximum freedom in movements and together with a double vent protection system and special drop stoppers allows to avoid the main problem, which is often the result of mounting "directly on the human body", i.e. high humidity.

The model is available in two color versions: beige or black.

Characteristics of the DPA lavaliere microphones:

DPA Type 6541 modular microphone system

This is a complete microphone kit for all kinds of everyday studio recordings, especially for high quality soloist, stringed or wind instrument recordings. The Type 3541 system comes complete with the MMC 4041 omnidirectional microphone capsule module and one of the preamplifiers for choice: either the high-voltage HMA 4000, the tube preamplifier module MMP 4000-T or the solid-state semi-conductor preamplifier module MMP 4000-S. All models are packed with an elastic shockmount for stand mounting, pop-filter, windscreen and special microphone cable. The maximum available cable length is 300 meters (including the HMA 4000 microphone amplifier). The microphone kit may be also fitted with an additional microphone module MMC 4041 (for stereo recording). The phase difference for a pair of microphones is ±10° (50 to 20000 Hz). The type 3541 system was created on the basis of cutting-edge developments of the company: the universal microphone capsule and tube preamplifier.

The capsule incorporates a diaphragm of 24 mm in diameter made of stainless steel and mounted on a steel base. This construction ensures unique protection from changes in sounding, caused by environmental changes in temperature. The capsule back-plate is polarized with 130 to 200 V via the HMA 4000 high voltage microphone amplifier/ power supply unit. The new microphone capsule with a large diaphragm is built according to the same technology as the one of the highly acclaimed Bruel & Kjaer type 4040 Hybrid Microphone with its unique double-preamplification system that made it extremely popular and widely adopted among professionals of sound recording. The Type 3541's frequency response has a 4-6 dB soft boost around 8 kHz. Thus, the MMC 4041 capsule is fully conforms, from the viewpoint of acknowledged specialists, to the specifications of its famous prototype, i.e. the Bruel & Kjaer 4040 microphone.

The modular design of the system provides a wide range of possibilities: firstly, you may attach microphone capsules with various characteristics; secondly, you may apply either a tube (the MMP 4000-T module, with its warm peculiar sounding) or a solid-state semi-conductor (the MMP 4000-S, not giving unwanted coloration) preamplifier. The tube microphone preamplifier module MMP 4000-T uses a pentode acting as a cathode-follower in the class-A output stage with a unity gain. The warm-up voltage of 6 V for this ultra-miniature tube is also provided by the HMA 4000 microphone amplifier/power supply unit. This scheme has shown itself to advantages for more than 30 years, since the Bruel & Kjaer company developed its first high-precision preamplifier for measuring microphones. Concerning its circuitry, the output stage of the MMP 4000-S solid-state preamp is identical with those, using discrete transistors, in the DPA high-voltage power supply microphone series. Like in the tube variant, the solid state transistor output stage performs as a class-A impedance converter with a unity gain.

The Type 3541 modular microphone system specifications:

I.S.P.A.-Engineering Co.

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