Models 960
and 960B

Single Channel


Ordering Information

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Models 960 & 960B
Wideband High-Gain Amplifier Instrument




Frequency Devices’ Models 960 & 960B instruments are single channel wideband high-gain amplifier instruments. The bandwidth is adjustable from 10 Hz to 1 MHz wide and the gain can be set from 0 dB to 80 dB in 1 dB steps.

The Amplifier has an input impedance of 1 MΩ shunted by 47pF in single ended mode and 2 MΩ shunted by 47pF in differential ended mode. The common mode rejection ratio (CMRR) is greater than 55 dB in differential mode.

Standard operational features include:

Adjustable gain to 80 dB
Adjustable bandwidth to 1 MHz
Differential or single ended input
Differential or single ended output
Output can drive 50Ω load
Off-set adjustment
Overload indicator
BNC Connectors for all I/O

The optional battery powered 960B is particularly well suited to applications requiring isolation from an electrically noisy primary power source.

Compact size and manual rotary switch front panel controls makes the 960 amplifier a popular, cost effective, easy-to-use solution for signal conditioning applications in the following areas:

Biomedical Applications
Data Recording/Playback
EKG/EEG Data Amplification
Medical Research
Seismic Analysis
Vibration Analysis

The 960 & 960B Amplifiers have a built in notch filter for 60 Hz or 50 Hz



960 Standard AC powered

960B AC powered, with battery option

Model 960
& 960B

Location of Front Panel
Terminals and Controls

A. POWER Status Lamp: This red LED indicates whether or not the amplifier power is on. On the 960B battery operated model this lamp will blink when the battery needs recharging.

B. dB Gain Switch: These selector switches allow the user to set the gain from 0 dB to 80 dB in 1 dB steps.

C. Bandwidth Switch: This switch changes the amplifier bandwidth from 10 Hz up to 1 MHz in decades.

D. Overload Lamp: This red LED comes on when the output of the amplifier is over driven and is no longer in linear gain mode. It will come on when the output is about 24 volts peak-to-peak. Reduce the gain or the input signal to turn this light off for best operation.

E. Input BNC: This is the input connector for the amplifier. In single input mode the input signal is applied to the center pin of the BNC connector and the shell of the BNC connector is grounded. In differential input mode the non-inverting input is the center pin of the BNC connector and the inverting input is the shell of the BNC connector.

F. Single/Differential Switch: This switch selects whether the amplifier input is in single ended or differential mode.

G. GROUND Terminal: This “Banana” type test jack provides neat and secure access to the internal ground. This terminal is a convenient junction for grounding external system and measurement instrumentation and/or apparatus.

H. OFFSET Adjust: This adjustment is intended to zero the offset that results from the instrument’s own internal circuitry.

I. Single/Differential Switch: This switch selects whether the amplifier output is in single ended or differential mode.

J. Output BNC: This is the output connector for the amplifier. In single output mode the output signal is applied to the center pin of the BNC connector and the shell of the BNC connector is grounded. In differential output mode the non-inverting output is the center pin of the BNC connector and the inverting output is the shell of the BNC connector. When this switch is in differential mode the gain of the amplifier is automatically adjusted to correct the output gain.

Model 960
& 960B

Location of Rear Panel
Terminals, Controls and Labels

K. IDENTIFICATION LABEL: This label identifies the Model number, filter type, serial number, date of manufacture, operating power limits and fuse requirements of the instrument.

L. AC POWER CONNECTION: Denotes plug and fuse location.

M. POWER ON/OFF Switch: Is a twoposition toggle switch on the back panel that interrupts/completes the power circuit. discrete increments of 10.

N. VOLTAGE Selector Module: For 230 Vac operation, use a screwdriver blade to pry open the module door (entry point next to window), remove the red fuse cartridge, replace the 0.2 Amp, 250 V fuse with a 0.1 Amp, 250 Volt fuse, remove the shorting clip in the other leg and replace it with a second 0.1 Amp fuse. Turn the module 180 degrees, re-insert and close the module door. The numerals 230V will now show in the module window. Reverse procedure to change back to 115V.

General Specifications

(@ 25°C and rated power Input)

Input Characteristics

Input Impedance

  • Differential: 2 M shunted by 47pF
  • Single Ended: 1 M Shunted by 47pF

Coupling                       DC

Input Voltage

  • Linear Differential*: 20V p-p
    (Gain Set at 0 dB)
  • Max Safe Differential Voltage:
    Any Continuous Value between ±40V
  • Bias Current: 1nA typ.; 2nA max.
  • Common Mode Rejection Ratio (0 dB Gain)
  • > 80dB @ 1kHz
  • > 70dB @ 10kHz
  • > 55dB @ 100kHz
  • Noise Voltage Density @70 dB Gain
    1 MHz Bandwidth:12 uVrms/ typ.

Minimum Discernable Signal

  • @ 1 kHz with 1 MHz Bandwidth
    1 mV @ 0 dB Gain
    20 uV @ 40 dB Gain
    13 uV @ 70 dB Gain

  • @ 1 kHz with 10 kHz Bandwidth
    1 mV @ 0 dB Gain
    10 uV @ 40 dB Gain
    2 uV @ 70 dB Gain

Output Characteristics

  • Small signal bandwidth: >1MHz @ 3 dB down
  • Maximum Output Voltage:
    10V p-p for RL = 50
    20V p-p for RL = 2k
    (DC to 500 kHz)

    5V p-p for RL = 50
    10V p-p for RL = 2k
    (500kHz to 1 MHz)
  • Output Max Power 0.25 Watt for RL= 50
  • Output Protection: Short Circuit to Ground
  • Output Impedance: 50 Single
    100 Differential
  • Gain Settings 0 to 80 dB in 1 dB steps
  • Gain Accuracy ±0.2 dB
  • Distortion @ 3.5 Vrms
    > 90 dB 1 kHz-10 kHz (at 0 dB Gain)
  • Overload Light Ligths at 24 V p-p
  • Transfer Functon of Filters
    Bessel with Constant Delay in Pass-Band
  • Offset Voltage: Adjustable to Zero
    Range 0-60 dB Gain ±0.5 VDC
    Range 70 dB Gain ±1.5 VDC

Power Supply
(AC Line Power Operation)
  • 960       10 Watts max.
  • 960B      15 Watts max.

Voltage Frequency Range-Rear Panel:

  • 115 V: 105 to 125Vac @ 50/60Hz
  • 230 V: 210 to 250Vac @ 50Hz
  • Fuse: 115 V=0.2 Amp., 230 V = 2X-0.1 Amp.

Battery Operation (960B)

  • Time for full Charge:
    10 to 12 Hrs. @ 20 ºC
  • Battery Life:
    Approx. 500 Charge-Discharge Cycles
  • Battery Charger:
    Automatic Uninterruptible
  • Charge Status Indicator-Front Panel: 3 Status Levels
  • Battery Operation:
    8 hours typ.


  • Operating Temperature:
    0 ºC to +50 ºC
  • Storage Temperature:
    -25 ºC to +70 ºC


  • Dimensions:
    3.7"H x 8.66"W x 10.6"D,
    9.4cmH x 22.0cmW x 27.0cmD
  • Weight
    960      3.5 Ibs; 1.58 kgs.
    960B     5.4 Ibs; 2.45 kgs.
  • Case Material: ABS plastic
  • Color: Light Gray

Ordering Information


Standard AC Powered Model

960B* AC powered with battery power option

*Please specify if you want the internal notch filter at 60 Hz or 50 Hz.


  1. See Item "Q" - Voltage selector Module. At time of shipment, Voltage is pre-selected in the 115 VAC position.
    For 230 VAC operation, this module must be rotated 180 degrees and an additional fuse must be added.

We hope the information given here will be helpful. The information is based on data and our best knowledge, and we consider the information to be true and accurate. Please read all statements, recommendations or suggestions herein in conjunction with our conditions of sale which apply to all goods supplied by us. We assume no responsibility for the use of these statements, recommendations or suggestions, nor do we intend them as a recommendation for any use which would infringe any patent or copyright.

Frequency Devices, Inc.
Your engineering partner for signal conditioning
  927 Fosse Rd
Ottawa, IL 61350



Phone: (815) 434-7800

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