g.USBamp: Specs & Features

g.USBamp - gtec's highest accuracy biosignal data acquisition and processing system

g.USBamp is a high-performance and high-accuracy biosignal amplifier and acquisition/processing system. It allows investigation of brain-, heart- and muscle-activity, eye movements, respiration, galvanic skin response and many other physiological and physical parameters. Due to its technical specifications and various software options, this instrument became a standard for many different fields of research, including neuropsychology, life science, medical research and biofeedback/neurofeedback/BCI research.

g.USBamp is USB enabled  and comes with 16  simultaneously sampled biosignal channels with 24 bits. A total of 4 independent grounds  guarantee no interference between the recorded signals. The amplifier connects easily to the USB socket on your PC/notebook and can immediately be used for data recording. Build a multi-channel system with more than 16 channels using multiple g.USBamp devices. A synchronization cable guarantees that all devices are sampling with exactly the same frequency. The amplifier has an input range of ± 250 mV, which allows recording of DC signals without saturation. Digital inputs and outputs allow the recording of trigger channels together with the biosignal channels to easily pass analysis results to the outside world. A short-cut input allows connecting the amplifier inputs quickly to ground potential to protect the amplifier against overflows, which may occur in operating rooms with gamma knifes or other environments. Ask also for our research version of the device, called g.USBamp-RESEARCH, for a special price.

Product Highlights

  • 16 DC-coupled wide-range input channels per unit, 4 independent grounds, record any type of signal (EEG/ECoG/ECG/EMG/EOG/spikes/...), connect various sensors, stack units for 32/48/64/... channels.
  • 24-bit resolution with simultaneous sampling of all channels with up to 38.4 kHz, digital signal filtering and preprocessing, connect via USB 2.0.
  • Works with passive and with active electrodes, 8 digital trigger inputs/unit, 4 digital outputs/unit, new simplified synchronization of units.
  • Internal digital bandpass and notch filters, built-in calibration unit and impedance checking.
  • Easy configuration and setup via the software, high-speed online data processing for SIMULINK and for LabVIEW available, recommended by BCI2000 & approved under OpenViBE
  • Driver package/API available
  • FDA cleared, safety class: II, conformity class: IIa, type of applied part: CF


"We have been using g.USBamp intensively for several years, in collaboration with Slovak Academy of Sciences, for measuring EEG on paretic patients as well as healthy individuals."
Prof. Igor Farkas, Comenius University, Center for Cognitive Science, SK
"We have used the g.USBamps for approximately four years now and the quality of the signals surpasses our greatest expectations. Last year we also invested in the g.Nautilus system and have been able to move from the more stringent laboratory conditions to the real world settings where BCIs find their applications. I would highly recommend both for anyone involved in BCI research.“
Associate Professor Natalie Mrachacz-Kersting, Aalborg University, DK
"The g.USBamp allows us to study effects of leadership interactions on both the leader's and the follower's brain and cognitive processes with great flexibility."
Prof. Dr. Jens Rowold, TU Dortmund, DE
"With g.USBamp you don't think about the amplifier anymore... You think about the EEG signals!"
Dr. Ales Holobar, University of Maribor, SI
"The g.USBamp amplifiers make it possible for us to have a mobile and easy to use EEG setup. The suitcases are perfect for quick transportation and rapid setup of the system."
Lukas Fiederer, University Hospital of Freiburg, DE
"The g.USBamp really improved the usability of the BCI, enabling interconnection with an external robotic agent to develop assistive technology for locked-in people, enabling them to put their thought in actions. "
Salvatore Tramonte, University of Palermo, IT

More Product Details

Input channel properties

g.USBamp uses wide-range DC-coupled amplifier technology in combination with 24-bit sampling. The result is an input voltage range of +/- 250 mV with a resolution of < 30 nV! This means that any electrophysiological signal can be recorded directly without additional hardware. Neither high electrode offset voltage nor big artifacts resulting from electrical or magnetic stimulation will saturate the amplifier inputs. This feature is an important requisite for various artifact treatment and correction techniques. The use of digital filters avoids hardware-related variations between channels. g.tec's active electrode system can also be connected directly, as well as all of our sensors (e.g. GSR, skin temperature, blood pressure, oxygen saturation, respiration effort and airflow, pulse plethysmography, acceleration, limb movements, snoring sounds, and many more).

Accuracy and data quality

Each of the 16 analog to digital converters operates at 2.4576 MHz. Oversampling 64 times yields the internal sampling rate of 38.400 Hz (per channel and for all channels!). In addition, a powerful floating point Digital Signal Processor performs oversampling and real-time filtering of the biosignal data (between 0 Hz - 2.400 Hz).
Therefore, a typical sampling frequency of 256 Hz yields an oversampling rate of 9.600. This results in a very high signal to noise ratio, which is especially critical when recording evoked potentials in the EEG or identifying small amplitude changes in high-resolution ECG recordings. You are measuring far below the noise-range of conventional amplifiers.

Add more channels or split systems

To set up a multi-channel system (32/48/64 channels), g.USBamps can be stacked. Just add another 16 channels by connecting one more unit to the system. To assure 100% simultaneous sampling of all channels, a simple "SYNC cable" is used to interconnect the devices (via a plug in the rear side). Each input channel can be used for any type of signal (electrophysiological signals or external physiological or physical sensors). On the other hand, if you have a 64 channel system consisting of 4 amplifiers, you can split the system to have 4 units available.

Test signal generation and calibration

The amplifier can generate an internal sinusoidal-, rectangular-, sawtooth or white-noise test signal. The amplitude and frequency of the signal can be modified to test the recording and analysis chain. An internal calibration unit periodically detects offset and gain values for each channel and uses these values for automatic internal correction. This technique yields the highest possible accuracy - especially critical for high resolution EEG and source derivation/localization.

Skin-electrode impedance

In order to obtain top-quality EEG recordings, the transition impedance between the skin and the electrode must be checked. The internal impedance testing unit measures the impedance for the individual electrodes and the results are displayed in the software. Bad electrodes can be identified easily and skin treatment and gel application can be performed during the impedance testing.

Software options

g.tec's philosophy is to provide a broad spectrum of software solutions for different groups of users (e.g. for engineers, researchers & scientists, physiologists, and medical staff, but also for software developers & programmers). From comfortable Windows-based recording software to MATLAB/SIMULINK and LabVIEW Highspeed Online-Processing environment and device drivers as well as APIs, you will find the appropriate tools for your application. Please see the list of related products/software below for more details. g.USBamp is also supported by some open source research communities such as OpenVibe and BCI2000. g.USBamp supports also the LSL (Lab Streaming Layer).

Important information

We give a full 5-year warranty on g.USBamp. g.USBamp is a safe certified medical device (CE and FDA) for research in humans, even for invasive recordings such as electrocorticography (ECoG). It must not be used for patient monitoring or determination of brain death. Medical diagnoses and decisions about treatment of diseases must not be based (solely) on results obtained with this device.

For ECoG and Spikes

Ad-Tech, PMT, Unique Medical and Cortec grid electrodes can be used for ECoG recordings. g.HEADstage can be used for neural spike recordings.


This figure shows EEG recordings with the g.HIamp during TMS stimulation with a TMS device from Mag&More. A g.GAMMAcap (size M) was prepared with passive g.LADYbird electrodes and the sampling rate was set to 38.400 Hz and no filters were selected. All electrode locations were prepared with abrasive gel to get a low electrode impedance. The TMS stimulation was done with a biphasic single pulse and about 300 repetitions applied with 1.1 Hz. The figure shows also the position of the TMS coil.

Beside g.HIamp, TMS can also be used with g.USBamp and g.Nautilus-PRO. The stimulation artifact with passive electrodes is typically 2 ms long, for active electrodes it is around 6 ms.

Simultaneous Measurement of EEG and tDCS

tDCS is a non-invasive method to stimulate the brain using constant, low current. This technology has been used in patients with brain injuries or psychiatric conditions like major depressive disorder. In addition, tDCS has been explored to alleviate memory deficits in Parkinson’s disease and Alzheimer’s disease, schizophrenia, and pain.

Read the full report on the g.tec blog: Simultaneous Measurement of EEG and tDCS

In summary, the measurement shows that tDCS is compatible with both passive and active electrodes with g.USBamp and g.Nautilus. There is a strong DC component in the raw data with tDCS, but it could be removed with a proper filter.
Two types of amplifiers, the g.USBamp and g.Nautilus, are available for this measurement. Both active and passive g.LADYbird electrodes are available with g.USBamp, while only active g.LADYbird is with g.Nautilus. The tDCS electrodes are 37 mm square, and are soaked in fresh saline solution before measurement.

AirRay ECoG Grids

Cortec AirRay ECoG grids with 64, 32 or 16 contacts can be connected to the 1.5 mm sockets of g.USBamp.

available colors for g.USBamp

We are proud to announce that our g.USBamp is available in amazing new colors! If you buy a g.USBamp you can choose your color!
usbamp_standardgrey usbamp_red usbamp_redlilac
standard grey (color code: RAL9006 FS) red (color code: RAL3003) red lilac (color code: RAL4001)
usbamp_gentialviolet reseda usbamp_deepblack
gentian violet (color code: RAL5010) reseda (color code: RAL6011) deep black (color code: RAL9005)

Available configurations

Hardware and Accessories

product no.: 0216 read more g.USBamp 16 channels — g.USBamp with 16 channels; 38.4 kHz per channel; 4 separated grounds

Complete Solutions

product no.: 6095 read more g.USBamp AEP Setup — complete setup for auditory stimulation experiments with g.USBamp; consisting of: ASSR, BAEP, AEP stimulation unit; audio trigger cable for g.USBamp UB; Lecture 4: Evoked potentials; bundle offer (0150, 0240_2, 4053)
read more g.BCI2000sys: Specs & Features — Complete BCI system for g.USBamp and g.MOBIlab+ with BCI2000
read more g.PHYSIOobserver: Specs & Features — Classify workload, emotions, movements based on physiological parameters in real-time

See some related products

Electrodes and Sensors

read more g.GAMMAsys: Specs & Features — active electrode system for EEG/EMG/EOG/ECG
read more g.SAHARA: Specs & Features — active dry EEG electrode system
read more g.Electrodes: Specs & Features — various active and passive electrodes for electrophysiological recordings
read more g.Sensors: Specs & Features — various sensors for physiological and physical signals

Hardware and Accessories

read more g.HEADstage: Specs & Features — miniaturized pre-amplifier
product no.: 0247 read more g.Power - for g.USBamp — medical mains power supply for g.USBamp; 110/230 V; 50/60 Hz power line; single 5 V supply
product no.: 0251a read more g.ACCUpack for g.USBamp — rechargeable battery pack; 12V and 5V, 4.5 Ah; for g.USBamp & adapter cable (253a)
product no.: 0252 read more Charging device for g.ACCUpack — automatic charging device for battery pack g.ACCUpack (0151a/c), 110/120 V; 50/60 Hz power line; regional adapter for EU, USA, UK,CN/AUS
product no.: 0225 read more g.USBamp cable for short-cut function (SC) — 3m cable with 3pin screw terminal
product no.: 0274 read more g.TRIGbox: Specs & Features — multimode trigger conditioner box
product no.: 0277 read more Trigger cable for g.USBamp UB — DIO break-out of cable to DSUB15 female; can be used e.g. for 4 trigger channels, from g.TRIGbox (D-sub 15), lenght approx. 3m, for g.USBamp 3.0 (UB-xxx.xx.xx)
product no.: 0278 read more Adapter cable for trigger cable — DSUB15-male to 6x BNC male adapter (including 6x CINCH adapter)
product no.: 0275 read more Trigger cable for g.USBamp UB — with open leads, for DIG I/O Trigger for UB-xxx.xx.xx
product no.: 0240_2 read more audio trigger cable for g.USBamp UB — DIG I/O of g.USBamp UB-xxxx.xx.xx to mindBEAGLE audio trigger adapter box
product no.: 0307b read more external trigger button UB — external trigger button for g.USBamp UB, with 2,5 m cable; 7 pin connector
product no.: 0276A read more Trigger cable for g.USBamp UB — DIG I/O 1 and DIG I/O 2 of g.USBamp UB-xxxx.xx.xx to D-Sub 25 male (PC-parallel-port pinout), 3m
product no.: 3012 read more medical isolation transformer — 600 VA, REO-MED, 6 outputs
product no.: 5051 read more g.USBamp water-proof heavy duty case — water-proof heavy duty case for g.USBamp equipment
product no.: 0219a read more ElectroCap-adapter cable to DSUB25 male for g.USBamp — adapter cable for 25 pin SUB-D 16 channels Electrocap for g.USBamp; standard: A: Screening
product no.: 10040 read more Medical device inspection — recurring medical device inspection (EN62353: 2008) for g.USBamp and g.BSamp
product no.: 0255 read more Connection cable XLTEK 32 channel to 2 g.USBamps — Connection cable male D-SUB 37pin to 2 g.USBamps; separate GND and REF cables included, connection length 1.75 m; special wiring to be confirmed at order
product no.: 0256 read more Connection box Stellate eAmp 64 channel to 4 g.USBamps — Connection box VHDCI connector to 4 g.USBamps; separate GND and REF cables included, connection length 1.75 m; special wiring to be confirmed at order
product no.: 0257 read more Special 64 channel break out and connection box Nihon Kohden Neurofax 64 channel to 4 g.USBamps — g.tec-65pin connector to 4 g.USBamps; separate GND and REF cables included, connection length 1.75 m; special wiring to be confirmed at order
product no.: 0258 read more Connection cable from 64 channel breakout box to Nihon Kohden Neurofax A connector — Nihon-Kohden-80pin connector to g.tec-65pin connector; connection length 10m
product no.: 0259 read more Connection cable from 64 channel breakout box to Nihon Kohden Neurofax B or C connector — Nihon-Kohden-68pin connector to g.tec-65pin connector; connection length 10m
product no.: 0226r read more shortcut jumper cable for 2 channels, extra long — shortcut cable for 2 channels; medical safety connector; length 500mm; can be daisy chained; color: red
product no.: 0226b read more shortcut jumper cable for 2 channels, extra long — shortcut cable for 2 channels; medical safety connector; length 500mm; can be daisy chained; color: blue
product no.: 0226y read more shortcut jumper cable for 2 channels, extra long — shortcut cable for 2 channels; medical safety connector; length 500mm; can be daisy chained; color: yellow

Related Media and Documents

g.USBamp 3.0

log in required
gUSBamp30Basics — 16/10/2017 — 2.01 MB
log in required
gUSBamp30_InstructionsForUse — 16/10/2017 — 1,014.96 kB


Lecture 1: EEG — 26/11/2015 — 6.94 MB
Lecture 2: BCI — 26/11/2015 — 4.23 MB
Lecture 3: ECG — 26/11/2015 — 21.23 MB
Lecture 4: EP — 23/09/2016 — 19.05 MB
Lecture 5: PhysioObserver — 26/11/2015 — 502.23 MB
Lecture 6: g.Nautilus Sports — 26/11/2015 — 106.97 MB