SMF-5 mkIII​

Stereo microphone amplifier with extremely low noise

A stereo microphone amplifier in its own class.

The SMF-5mkIII is the succesor to the esteemed SMF-5mkII. SMF-5mkIII has two extremely low-noise channels designed for recordings where the lowest possible noise and distortion are required. The channels are completely separated all the way from input to output with separate level controls. The difference between mkII and mkIII is above all, even lower noise and a wider input voltage range, 10–35 V. The input transformers located in the device are from Lundahl, which has an extended frequency range down to 5 Hz. The harmonic distortion at 30 dB gain is 0.0006% and equivalent input noise is down to 131 dBu. Unlike its predecessor, this one doesn’t have internal batteries, but the wide input voltage range makes it easy to power from many standard battery packs available for portable recording. The battery and amplifier can be stored in the specially designed PortaBrace bag, which can be purchased as an accessory. The SMF-5mkIII is built in a robust EMC shielded aluminium box.

0006% THD+N (extremely low distortion)

5 Hz–40 kHz (wide frequency range)

Equivalent input noise -131 dBu (ultra-low noise)

Contact Marenius via the form below to order the SMF-5 mk3.
Alternatively, call us at +46 31-691610

SMF-5 mkIII specifications

Fs = 48 kHz, 20 to 22 kHz BW, 1 kHz test tone, 0 dBFS = +16 dBu (unless otherwise specified).

  • Input impedance: 1kΩ
  • Maximum input level (XLR): -6dBu
  • Maximum output level (TRS): +24dBu (600Ω)
  • Output impedance: 2x22kΩ
  • Gain: 30-70dB
  • Frequency response: 5Hz-40kHz (-3dB)
  • THD+N (1 kHz, 30 dB gain): 0.0006%
  • Voltage range: 10-35VDC
  • Size: 140x60x136mm
  • Weight: ca 900g