• D440-4

  • Low-noise human EMG Amplifier

  • Product No: NS-1051
  • Manufacturer: Digitimer
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The Digitimer D440 Isolated Amplifier is a low noise solution for human EMG studies, specifically those related to nerve excitability. Low noise performance is significantly enhanced through the use of a Driven Right Leg (DRL) circuit which reduces Common-mode interference.  The D440 features an amplification range of x100 to x20k.  The gain, filter and mode settings for individual channels are adjusted using Digitimer’s “virtual front panel” software or other software via a COM interface.  The D440 is available in two versions, the D440-2 (two channels) and the D440-4 (four channels).  Each channel features a pair of 1.5mm touch proof sockets for active and reference electrode connection, but provision is also made for shielded leads with 5-pin DIN connectors.  Each amplifier is supplied with a signal output cable (D connector to multiple BNC) and electrode connection cable (1.2m long with 3x 1.5mm DIN42802 sockets for electrode connection and 270 degree 5-pin DIN plug for amplifier connection).



System Features

  • Portable, standalone design
  • Extremely low noise
  • Rapid recovery from stimulus artefacts e.g magnetic or electrical stimulation
  • AC and DC operating modes
  • Analogue signal output for ultimate compatibility with data acquisition systems
  • Computer control through dedicated Digitimer software or external programs (via COM interface)
  • Designed for human research applications, including nerve excitability testing


Technical Specifications

Input impedance:

Each channel 1Gohm.

Common Mode Rejection:

-132dB @ 10Hz, -130dB @ 50Hz, -126dB @1kHz

On/off control of individual channels:

The electronic inputs of individual channels can be grounded reducing cross-talk noise when recording from fewer channels. This also disconnects the subject from the electronics.

Common ‘Driven Right Leg’ system:

With adjustable gain for lower noise.

Overall system GAIN for each channel:

x100 (10mV/V) to x20,000 (5µV/V).


±5V range. The rear panel has a BNC socket for monitoring the output of channel 1 (this signal is mirrored on a 9-way 'D' connector on the rear panel along with the output signals of channels 2, 3 and 4). A signal output cable terminated with an appropriate number of BNC connections is supplied with each amplifier.

Low-cut filter: 

Selectable between 0 (DC), 0.159 Hz, 1Hz, 3Hz, 5Hz, 10Hz, 30 Hz, and 50Hz for -3dB and are first order.

High-cut filter:

Selectable between 1000Hz, 3000Hz, 5000Hz, and 10kHz for -3dB and are second order, low phase shift Bessel style filters.