Digidata 1550A plus HumSilencer Feature

A low-noise data acquisition system with single-click 50/60 Hz line-frequency noise elimination in less than one second.

Effective immediately, the Digidata 1550A0 and 1550A1 Systems have been replaced by equivalent Digidata 1550B0 and 1550B1 Systems respectively. To learn more about the Digidata 1550B System, please visit here.

The Axon Technical Support Team at Molecular Devices will continue supporting all legacy Digidata systems, including Digidata 1550A series, for the foreseeable future.

For a variety of electrophysiology recordings including single-channel recordings, whole-cell voltage- and current-clamp recordings, intracellular sharp electrode recordings, extracellular field potential recordings in ion channel, neuroscience, nanopore, voltammetry studies.

The Axon™ Digidata® 1550A plus HumSilencer™ Adaptive Noise Cancellation brings a new level of simplicity to your electrophysiology workflows. Blending the precision and quality of the Axon Digidata 1550 with fast, hassle-free 50/60 Hz line-frequency noise elimination, the Digidata 1550A frees you from the anxiety of this often unanticipated issue. Experiments can move forward more reliably and small biological signals no longer remain obscured by noise now that you have the ability to eliminate line-frequency noise in less than one second and with only a single click.


What Is the HumSilencer Feature?

The HumSilencer feature is advanced technology that learns the local line-frequency noise patterns and associated high-frequency harmonics and removes them from the incoming signal in a filter-free way. Controlled through a simple ON/OFF check box in the Axon AxoScope or Axon Clampex software, the HumSilencer is easy to use, enabling (or disabling) subtraction of line-frequency noise from your signal with a single click.


Humsilencer Data Graph

Download the Application Note for more details on the data shown here.

If the pattern of the line frequency noise changes, such as by the introduction of a new noise source or through an increase in existing noise, HumSilencer rapidly learns and adapts. The new noise is eliminated in less than one second, and for amplitudes at the digitizer’s analog input of up to 20 V, peak-to-peak. 

The HumSilencer feature is not a filter and does not have a filtering effect on acquired signals; nor does the HumSilencer system cause signal distortion, such as frequency change, amplitude attenuation, phase shift, or DC voltage change. It is an adaptive, built-in solution to the problem of line-frequency noise.

With the Digidata 1550A plus HumSilencer, you get all the functions and capabilities of the Digidata 1550, with the added ease and convenience of the powerful HumSilencer


Basic Ion Channel Research

Ion channels are pore proteins that are involved in a large variety of physiological processes. Basic research in the ion channel field furthers the understanding of ion channel function as well as their roles within cellular pathways and processes. Single-channel research helps with elucidating the mechanisms underlying ion channel function on a single-molecule level. Whole-cell and perforated patch clamp recordings are typically used to investigate the action of modulators on entire populations of ion channels in the membrane of a cell. Learn more.

Cell Pathway Analysis

Ion channels are involved in many cell pathways and understanding the function of ion channels in response to changes in membrane potential or the presence or absence of other molecules is important in order to understand exactly how ion channels participate in normal and abnormal biological processes such as cell differentiation and migration, disease states, neuronal communications, etc. Learn more.

Disease Research

Ion channels play a role in many diseases, including hypertension, cardiac arrhythmias, gastrointestinal, immune and neuromuscular disorders, pathological pain and cancer. By understanding the exact role that ion channels play in a particular disease, researchers might be able to find a way to affect the ion channel in such a way as to alter the course of the disease.

Safety Assessment

A critical part of drug discovery involves safety assessments, such as hERG testing, in order to eliminate any compounds with potential safety concerns. Conventional patch clamp has played an important role in collecting evidence for the absence of side effects before submission of a drug candidate to regulatory authorities. Even if automated electrophysiology has shifted safety testing to earlier stages in the drug discovery process, follow-up with conventional patch clamp is an essential step in the workflow. Learn more.

AxoScope 10.5 Software

AxoScope 10.5 Software is a turn-key data acquisition and analysis program for Microsoft Windows, designed to replace oscilloscopes, chart recorders, and FM tape recorders. AxoScope 10.5 Software provides from eight to sixteen channels of analog acquisition and four different acquisition modes.

Data can be acquired and displayed continuously in Gap-Free mode up to the supported sampling rate of the digitizer. Other acquisition modes supported by AxoScope 10.5 Software are threshold-triggered Fixed-Length Events, Variable-Length Events or High-Speed Oscilloscope modes. Tags and comments can be added to the data in real time. Analog and digital output holding values can be altered.

AxoScope 10.5 Software opens Axon-format ABF data files and enables quick analysis of sections of interest with an array of browsing and basic analysis tools. Data and page layout can be reviewed before printing. Additional features include voice tags, which allow tagging of data with spoken comments*, low-pass and high-pass digital filtering of incoming data, and Store Trace, which freezes a snapshot of a waveform on the screen for comparison with a subsequent input.

In combination with pCLAMP 10.5 Software, the Digidata® 1550A System forms the data acquisition backbone of a set-up like those used in many electrophysiology labs around the world. The Clampex Data Acquisition Module, which is part of the pCLAMP Software, makes optimal use of the features of the Digidata 1550A Low-Noise Data Acquisition System.

* Requires a sound chip in the host computer and a microphone. 

Developer Support

Software testbeds are available to help programmers write data acquisition programs for Digidata Digitizers. These testbeds include sample code and DLL drivers for Windows programs. For non-Windows programs, it is suggested that you write a C wrapper for our API.

There are four testbeds currently available through our Customer Support page:

  • The Digidata 1550A Testbed allows programs to be created to control the Digidata 1550A Digitizer. The sample application requires a Digidata 1550A Digitizer to run.
  • The Digidata 1550 Testbed allows programs to be created to control the Digidata 1550 Digitizer. The sample application requires a Digidata 1550 Digitizer to run.
  • The Digidata 1440A Testbed allows programs to be created to control the Digidata 1440A Digitizer. The sample application requires a Digidata 1440A Digitizer to run.
  • The Digidata 132x Testbed allows programs to be created to control the product line of Digidata 1320A, 1321A and 1322A digitizers. Note that the Adaptec WinASPI layer is also required.

Please note that technical support is not available for writing programs using these testbeds.


  • Eliminates 50/60 Hz line-frequency noise and associated high frequency harmonics in less than one second and with a single click
  • Digitizes a wide range of input signals from -10 to +10 V
  • Eliminates a maximum noise amplitude of up to 20 V, peak-to-peak
  • 8 analog input channels to digitize acquired signals up to 500 kHz independently
  • 8 analog output channels to send command voltage output independently
  • 8 digital out channels to control the periphery equipment used in sophisticated experiments
  • Independent analog-to-digital converters for each input channel ensure low crosstalk levels and high data acquisition rates.
  • USB 2.0 connection allows operation on virtually any current PC computer running Microsoft Windows 7 (32-bit or 64-bit) Operating System, including laptops.
  • 16-bit resolution data
  • State-of-the-art signal-to-noise ratio
  • All signal connectors on the front panel for ease of access and maintenance of the electrophysiology set-up
  • Rack-mount case for tidy installation of all components in the electrophysiology set-up
  • User guide written by scientific consultants, with the assistance of Axon Instruments staff, for straightforward start-up and as an in-depth reference.

General Specifications

General Specifications


Maximum input signal 
(total of noise + signal)
±10 V
Maximum noise amplitude 20 V, peak-to-peak (on a 0 V signal)
Noise cancellation Line-frequency (50 Hz / 60 Hz) and harmonics to 10 kHz
Cancellation response time < 1 second

Analog Inputs

Number of input channels 8 single-ended
Number of ADCs 8
Sampling rates
1 Hz - 500 kHz; Maximum aggregate throughput rate is 500 kHz x 8 input channels = 4 Megasamples/s
Resolution 16-bit
Input range -10.000 V to +10.000 V
Input resistance >1 MΩ
Gain value 1

Analog Outputs

Number of channels 8
Number of DACs 8
Sampling rates 1 Hz -  500 kHz
Resolution 16-bit
Output range -10.000 V to +10.000 V
Output impedance <  0.5 Ω
Output short circuit to signal ground ±25 mA

Digital Outputs

Number of bits 8 (of 16) supported in software
SCOPE Dedicated trigger output
Output driver Advanced CMOS (AC) compatible
Output current ±4 mA source, cable
Type USB 2.0 braided
Length 3 meters

Trigger Inputs

Input type TTL compatible
TAG Rising-edge sensitive
START Rising-edge sensitive

Detail Specifications


Description Details Part Number
Axoclamp 900A Headstage HS-9A X0.1U x0.1 headstage 1-2950-0359
Axoclamp 900A Headstage HS-9A X1U x1 headstage 1-2950-0360
Axoclamp 900A Headstage HS-9A X10U x10 headstage 1-2950-0361
Axoclamp 900A Headstage VG-9A X10U x10 virtual ground headstage 1-2950-0362
Axoclamp 900A Headstage VG-9A X100U x100 virtual ground headstage 1-2950-0363
MultiClamp 700B Headstage CV-7B Patch-clamp headstage 1-CV-7B
MultiClamp 700B Headstage CV-7B/BL Bilayer headstage 1-CV-7B/BL
MultiClamp 700B Headstage CV-7B/EC Electrochemistry headstage 1-CV-7B/EC

Electrode holders, adapters, and holder components

Description Details Part Number
Electrode Holder for U-Type Headstages Fits glass pipettes with outer diameter of 1.0 - 1.7 mm 1-HL-U
Electrode Holder Replacement Caps Set of 2 polycarbonate caps for HL-U holders 1-HL-CAP
Cone Washers 1.1mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.0 - 1.1 mm 1-HLC-11
Cone Washers 1.3mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.1 - 1.3 mm 1-HLC-13
Cone Washers 1.5mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.3 - 1.5 mm 1-HLC-15
Cone Washers 1.7mm ID Set of 10 orange cone washers for HL-U holders, fit glass with outer diameter of 1.5 - 1.7 mm 1-HLC-17
Pins 1mm for HL-U Holders Set of 3 brass pins for HL-U holders, 1mm 1-HLP-U
2mm Plugs with Solder Cups Set of 5 general purpose gold plugs, 2mm, with solder cups 1-HLP-0
Silver Wire Set of 5 Ag wires, 0.25mm diameter, 50mm long 1-HLA-005
Silicone Tubing for Silver Wire 1mm ID x 70mm Long Silicone Tubing 1-HLT-70
Silver/Silver Chloride Pellet Assemblies Set of 3 Ag/AgCl pellet assemblies 1-HLA-003
Adapter For BNC Holders To U-Type Headstages Connects BNC holders to CV and HS headstages with threaded collets (U-type) 1-HLB-U
Right-Angle Adapter for HL-U Electrode Holders Fits CV and HS headstages with threaded collets (U-type) 1-HLR-U

Model Cells

Description Details Part Number
Model Cell for Oocytes Axoclamp/ GeneClamp model cell for oocytes. Connects to U-type HS series headstages 1-MCO-2U
Model Cell for TEVC / DSEVC Axoclamp/ GeneClamp model cell for two-electrode voltage clamp/ discontinuous single-electrode voltage-clamp conditions. Connects to U-type HS series headstages 1-CLAMP-1U
Model Cell for Whole Cell/ Single Channels Axopatch/ GeneClamp/ MultiClamp model cell for whole-cell / single-channel patch-clamp conditions. Connects to U-type CV series headstages 1-PATCH-1U
Model Cell for Bilayers Axopatch/ GeneClamp/ MultiClamp model cell for bilayer conditions. Connects to U-type CV series headstages 1-MCB-1U


Description Details Part Number
Cable To Connect Axoclamp 2 Headstages To Axoclamp 900A Amplifier Allows Axoclamp 2 headstages (HS-2, VG-2) to be used on Axoclamp 900A Amplifiers 1-2100-0934


Description Details Part Number
SoftPanel Amplifier Control Unit Provides physical knob and button control for computer-controlled Axoclamp 900-series and MultiClamp 700-series amplifiers. Requires a USB connection. 1-SOFTPANEL (USB)
Remote Buzz For Axoclamp 900A Hand-held buzz duration control for Axoclamp 900A Amplifier (1-50ms) 1-2950-0366
Silver/Silver Chloride Pellet Assemblies Set of 3 Ag/AgCl pellet assembly and Ag wire 1-HLA-003