D440 2 or 4 Channel Isolated EMG Amplifier

D440 2 or 4 Channel Isolated EMG Amplifier


Manufacturer's Net List Price


  • 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



The Digitimer D440 Isolated EMG Amplifier is a a portable and standalone, low noise solution for human EMG studies, specifically those related to nerve excitability. The D440 features an amplification range of x100 to x20k. The gain, filter and mode settings for individual channels are adjusted using our own “virtual front panel” software or other software via a COM interface.  The D440 is available in two versions, the D440-2 – a 2 Channel Isolated Amplifier – and the D440-4 – a 4 Channel Isolated Amplifier.

AC and DC Operating Modes

The D440 is designed to operate in AC and DC differential modes and includes a manually activated or externally gated de-block function, which can be useful for minimising the effects of magnetic stimulation artifacts.

Compatible with Standard Electrode Connectors

Electrodes are connected to the front panel via 1.5mm DIN 42 802 or standard 5-pole DIN connectors.

Designed for Human Research Applications

The D440 has been designed to meet international medical device design standards, however, it is NOT a medical device and its use is limited to human research studies only.

QtracW – Threshold Tracking & Nerve Excitability

The D440 has been designed to appeal to users of our DS5 Bipolar Constant Current Stimulator, who employ the DS5 and QtracW software to research human nerve excitability. This application requires a very low noise amplifier, which outputs an analog signal and can be controlled directly by the QtracW data acquisition software. These requirements are fully satisfied by the Digitimer D440 Isolated Amplifier.

Analogue Outputs for DAQ Hardware Compatibility

Each D440 amplifier is supplied with a signal output cable (D440-OL-xx, D connector to multiple BNC), electrode connection cable (D-440-IL, 1.2m long with 3x 1.5mm DIN42802 sockets for electrode connection and 270 degree 5-pin DIN plug for amplifier connection) and USB cable for connection to the host computer.

Features Overview

  • Two (D440-2) or Four (D440-4) Channels of amplification, filtering and isolation – with independent control of each channel.
  • Primarily designed as an AC amplifier, the D440 will also operate in DC mode.
  • Input impedance of each channel is 1Gohm.
  • 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.
  • Overall system GAIN for each channel x100 (10mV/V) to x20,000 (50μV/V).
  • Outputs have a ±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 settings are selectable between 0 (DC), 0.159 Hz, 1Hz, 3Hz, 5Hz, 10Hz, 30 Hz and 50Hz for -3dB and are first order.
  • HIGH-CUT FILTER settings are selectable between 1kHz, 3kHz, 5kHz, and 10kHz for -3dB and are second order, low phase shift Bessel style filters.
  • The front panel contains three LEDs which are used to indicate the units power supply status, Internal-Error and Data-Bus Busy.
  • The rear panel contains a mains IEC inlet socket with mains voltage selection, fuses and mains on/off switch, as well a 9-way “D” connector, for connecting channels to a data acquisition system and a USB port for connection to a Windows PC.
  • A push button Deblock control is present on the front panel with a TTL compatible Deblock facility available via a BNC connector on the rear panel.
  • Standalone Use – Previous amplifier settings will be maintained if a D440 is used without PC connection.
  • Supplied with “virtual front panel” control software to adjust the settings of a single D440 amplifier. For applications requiring more than 4 channels, we recommend our D360 8-Channel Isolated Patient Amplifier.
  • The D440 includes a COM interface to allow other software applications to control the amplifier settings.
  • Mains operating voltage between 115V and 230V (switch selectable) at 50-60Hz. Note: for locations with low mains voltage (< 105V), such as some areas of Japan, a custom D440 with a replaced mains transformer will be required

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Product Information

D440 Isolated Amplifier

D440 Control Software




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  • Mains Lead (Power Cord)
  • Operator’s Manual
  • Electrode Connection Input Lead (D440-IL, one per channel)
  • Output Lead (D440-OL-2CH or D440-OL-4CH)
  • USB Cable (D-USB-F)
  • D440 Virtual Front Panel Control Software (supplied on USB Flash Drive)


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D440 2 Channel Isolated Amplifier, D440 4 Channel Isolated Amplifier