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Microtech Gefell UMT70S

Capacitor Microphone By Paul White
Published May 1995

Microtech's original UM70 set the affordable capacitor mic ball rolling, but now there's a transformerless version featuring a new housing. Paul White took it for a test drive.

When the UM70 first appeared on the market, it challenged the assumption that a good‑sounding capacitor mic had to cost the earth. Though the build quality lagged a little behind what was considered normal in the West, the capsule, based on an original Neumann large‑diaphragm design, delivered stunning sound quality that many users felt sounded very close to Neumann's own U87. Since then the build quality has improved and the price has also increased, but compared to the big‑name European mics, the UM70 is still a very attractive proposition.

The latest mic in the Microtech range is the UMT70S, a transformerless version of the UM70 offering three switchable pickup patterns: Omni, Cardioid and Figure‑of‑Eight, though a cardioid‑only version is also available in the form of the MT71S. The new housing feels heavier than the original, featuring a slimmer body, and finished in black matte nickel, though champagne‑colour is an option. The overall standard of design and construction seems a lot better than that of the original UM70, an example of which still resides in my mic locker.

Pattern switching is achieved by rotating the bevelled flange below the mic basket, while a recessed DIP switch arrangement provides for bass cut and a 10dB pad. Curiously, there is no model number at all on the mic body — just the manufacturer's logo and country of origin (Germany). The transformerless preamp is a relatively new design and features a symmetrical output stage. The benefits are lower noise, better transient response and lower susceptibility to RF interference. It is also claimed that this mic has a wider dynamic range than the original.

The frequency range of the mic is quoted as being 40Hz to 18kHz, though there is no pretention that the response is flat over this range. From the frequency response plot, it can be seen that there's a very gentle LF roll‑off below 1kHz which pulls the 50Hz point down around ‑4dB. Above that, the response is nominally flat to around 15kHz, except that there's a deliberate presence peak at around 7kHz, giving a lift of around 3dB. Above 15kHz, the response rolls gently away and is around 6dB down at 20kHz.

In Use

Comparing the mic with the original UM70, the sensitivity seems comparable, but there's a noticeable increase in HF detail, no doubt attributable to the improved transient response. The sound is still very warm, but somehow there's more 'air' around the top end. The self‑noise of the mic is also a little lower, but then noise was never a problem with the original, as most studio applications involve relatively close miking anyway.

At a retail price of over £900, the UMT70S can't really be considered a budget mic, but might be better regarded as a serious professional mic with a very competitive price tag. Most of the big names can only offer cardioid‑only mics at this price, and if you only need a cardioid mic, you can opt to pay less and buy the MT71S. I must say that I'm very impressed with the constructional quality of this mic as well as the sound, and it's hard to believe that this mic and my old UM70 were made by the same company.

It's evident that Microtech Gefell have outgrown their bargain‑basement image, and the UMT70S is a serious pro capacitor mic by any standards. Microtech Gefell no longer build the cheapest mics, but I think it's fair to say that they still build some of the best value mics around.

Brief Specification

  • Polar Patterns Cardioid; omni; figure‑of‑eight
  • Frequency response 40Hz‑18kHz
  • Sensitivity at 1kHz 13mV/Pa +/‑ 3dB
  • Max SPL 134dB (144dB with 10dB pad)
  • Equivalent Noise 14dBA
  • Phantom Power 48V (3mA)
  • Nominal Impedance 150 Ohms
  • Dynamic Range of Preamp 120dB
  • Connector balanced XLR
  • Dimensions Head diameter 42mm; body diameter 21mm; total length 217mm.


  • Classy, detailed sound.
  • Good technical spec.
  • Well constructed.


  • All accessories other than the wooden case are optional.


A serious, professional, multi‑pattern mic priced to appeal to both the audio professional and the serious project studio owner.