Extracellular Amplifier

Extracellular Amplifier

Model npi.EXT-02B

  • Two recording channels with stimulus control, differential INPUTS
  • One power supply for up to four EXT-02 B amplifiers, one REL-08 B and one AUD-08 B system
  • Two different OUTPUTS:
  • DC with GAIN x10 and OFFSET control, range ± 1 V
  • AC with GAIN x10 to x10k, HIGHPASS and LOWPASS filtered
  • HIGHPASS filter (AC): 0.1, 1, 10, 30, 100, 300 Hz
  • LOWPASS filter (AC): 500, 1k, 3k, 5k, 10k, 20k Hz
  • NOTCH filter (AC and DC): 50 Hz or 60 Hz, activated by switch
  • MONITORS (telegraphs) for filters and gain
  • External STIMULUS input with 2 mm banana jacks, STIMULUS CONTROL with switch or TTL signal
  • Data bus connection to AUD-08 B and REL-08 B

Available headstages:

  • Standard headstage with one, two or four channels
  • Standard headstage with direct stimulation through the same electrode
  • Miniature headstage with one, two, four, six or eight channels (via breakout box)
  • Miniature headstage with direct stimulation via separate electrode or switchable
  • Tetrode miniature headstage with four channels


In extracellular recording usually very small potentials in the µV range are measured. This requires high amplification and often also filtering.

npi’s range of extracellular amplifiers meet these requirements. They are available as desktop instruments, in a 19” rackmount cabinet or as module for the EPMS modular system. All npi extracellular amplifiers have high pass and low pass filter and gain up to 10000. They allow DC measurements and AC recordings in which offsets are cancelled automatically. Audio monitors and electrode resistance meters are available as well. The use of external power supplies and high quality electronics ensure low-noise recording of small signals.

Models include:

  • analog displays for potential
  • variable gain up to 10k
  • offset and capacity compensation
  • tunable highpass/lowpass filters

Most systems are equipped with a small headstage with high impedance differential inputs to suppress noise and other distortions.


Input (headstage)

>10-12 W, range ±1 V

Differential Input

CMR >90 dB at 1 kHz (tested with 0 W input resistance)

Input Capacitance

30 pF

OFFSET compensation

set by potentiometer, range: ±1 V


single pole, attenuation: -6 dB / octave,
|corner frequencies (Hz): 0.1, 1, 10, 30, 100, 300


single pole, attenuation: -6 dB/octave,
corner frequencies (Hz): 500, 1k, 3k, 5k, 10k, 20k


rotary-switch 10-100-1k-10k


range: ±10 V into 1 kW / ±1 V into 50 W

Power Supply

18V, AC, min. 1.5 A


305 x 180 x 105 mm³ (W x D x H)



Input (headstage)

>1012 W, range ±1 V

Headstage Size

70 x 26 x 26 mm3

Holding Bar

length: 150 mm; diameter: 8 mm


Visone, R., Lozano-Juan, F., Marzorati, S., Rivolta, M. W., Pesenti, E., Redaelli, A., Sassi, R., Rasponi, M., & Occhetta, P. (2023). Predicting human cardiac QT alterations and pro-arrhythmic effects of compounds with a 3D beating heart-on-chip platform. Toxicological Sciences : An Official Journal of the Society of Toxicology, 191(1), 47–60. https://doi.org/10.1093/toxsci/kfac108

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Timmermann, A., Tascio, D., Jabs, R., Boehlen, A., Domingos, C., Skubal, M., Huang, W., Kirchhoff, F., Henneberger, C., Bilkei-Gorzo, A., Seifert, G., & Steinhäuser, C. (2023). Dysfunction of NG2 glial cells affects neuronal plasticity and behavior. GLIA. https://doi.org/10.1002/glia.24352

Ferrari, E., Visone, R., Monti, E., Torretta, E., Moretti, M., Occhetta, P., & Rasponi, M. (2023). LivHeart: A Multi Organ-on-Chip Platform to Study Off-Target Cardiotoxicity of Drugs Upon Liver Metabolism. Advanced Materials Technologies. https://doi.org/10.1002/admt.202201435

Confettura, A. D., Cuboni, E., Ammar, M. R., Jia, S., Gomes, G. M., Yuanxiang, P. A., Raman, R., Li, T., Grochowska, K. M., Ahrends, R., Karpova, A., Dityatev, A., & Kreutz, M. R. (2022). Neddylation-dependent protein degradation is a nexus between synaptic insulin resistance, neuroinflammation and Alzheimer’s disease. Translational Neurodegeneration, 11(1). https://doi.org/10.1186/s40035-021-00277-8

Muhia, M., YuanXiang, P. A., Sedlacik, J., Schwarz, J. R., Heisler, F. F., Gromova, K. V., Thies, E., Breiden, P., Pechmann, Y., Kreutz, M. R., & Kneussel, M. (2022). Muskelin regulates actin-dependent synaptic changes and intrinsic brain activity relevant to behavioral and cognitive processes. Communications Biology, 5(1). https://doi.org/10.1038/s42003-022-03446-1


Product Manuals

Related Products

Extracellular Amplifier
Extracellular Amplifier
Model npi.EXT-02F

In extracellular recording usually very small potentials in the µV range are measured. This requires high amplification and often also filtering. npi’s range of extracellular amplifiers meet these requirements.

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