A-MSystems 1700 User manual
Contents
General Description........................................................................................................... 1
Operating Instructions....................................................................................................... 4
Theory of Operation........................................................................................................... 6
Specifications .................................................................................................................... 8
Warranty and Service ....................................................................................................... 10
Each Differential AC Amplifier is delivered complete with:
Four 3’ Cables
Rack Mount Hardware
NOTE
This instrument is not intended for clinical measurements using human
subjects. A-M Systems does not assume responsibility for injury or
damage due to the misuse of this instrument.
A-M Systems
131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
1
Telephone: 800-426-1306 * 360-683-8300 * FAX: 360-683-3525
General Description
Instrument Features
The Four-Channel Differential AC Amplifier Model 1700 is designed to amplify cellular
neurophysiological signals in applications requiring high gain, high input impedance,
low noise, high common-mode rejection, and powerline interference rejection. Typical
applications include: extracellular nerve recordings using suction or hook electrodes;
electromyographic (EMG) recordings from muscle using wire or needle electrodes;
EEG, ERG and EKG recordings. The instrument is not intended for clinical or
operating room measurements using humans.
The instrument consists of a high input impedance, low-noise differential input stage,
followed by high-frequency, low-frequency, and notch filters. The gain settings are
x100, x1000 or x10 000. It is also possible to connect a stimulator to each amplifier
channel and stimulate through the recording electrodes. The Model 1700 contains
four identical and independent amplifier channels in a single instrument, useful for
making extracellular recordings from several sources being monitored simultaneously.
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
2
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Controls and Connectors
INPUT: This 5-pin connector attaches the electrode cable
to the amplifier channel. The pin and electrode cable
wire designations can be found in the “Operating
Instructions” section in this manual.
STIMULUS: This 5-pin connector allows for external
signals to be applied to the electrode.
MODE (STIM-REC): This switch sets the channel to
Stimulus Mode or Record Mode. In Stimulus Mode,
the INPUT connector is connected to the signal from the STIMULUS connector and the
OUTPUT connector is disabled. In Record Mode, the INPUT connector is connected to
the amplification circuits and the signal is available at the OUTPUT connector.
GAIN: This rotary switch sets the amplifier gain to x100, x1000, or x10 000.
LOW CUT-OFF: This rotary switch selects the cut-off frequency of the Low Frequency
Filter for the amplifier channel. Signals below the cut-off frequency are reduced by a
factor of 100 (40 dB) per decade decrease in the input signal frequency. The Low
Frequency Filter may be used to reduce slow DC level variations in the signal being
recorded (See Bode plot page 3).
HIGH CUT-OFF: This rotary switch selects the cut-off frequency of the High Frequency
Filter for the amplifier channel. Signals above the cut-off frequency are reduced by a
factor of 100 (40dB) per decade increase in the input signal frequency.
NOTCH (IN-OUT): This switch allows the Notch Filter to be included (IN) in or excluded
(OUT) from the signal processing circuitry on a per channel basis. When radiation from
the power lines is present, it is picked up by recording electrodes creating unwanted
interference in the recording signal. This interference can be reduced through proper
grounding and shielding techniques. Occasionally it is impossible to reduce this
interference sufficiently to record relatively noise-free signals. The Notch Filter can
sufficiently reduce the interference. However, this filter causes some distortion in
signals below 100 Hz.
OUTPUT: This BNC connector provides the output signal from the amplifier channel.
POWER: This switch turns on power to all four amplifier channels.
GND: This connector is attached to the circuit ground for all four amplifier channels. To
obtain low-noise recordings, this terminal may be used to make a ground connection
to the recording medium.
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
4
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Operating Instructions
General Notes
Any amplifier channel not currently in use should have its MODE switch in the STIM
position to protect the amplifier inputs. This grounds the inputs to the differential
amplifier circuitry.
Set the GAIN, LOW CUT-OFF filter, HIGH CUT-OFF filter, and NOTCH filter according to the
frequency content of the signal to be recorded.
While recording from biological preparations take care to keep all instrument cables as
far away as possible from the recording situation. This will assist in maintaining proper
grounding and shielding to insure a minimum of electrical interference.
Input cables are available to connect the amplifier to extracellular electrodes and/or
stimulators. These cables will attach to either the INPUT or the STIMULUS connector.
Additional cables can be ordered (catalog #692000, #701700). One end of each cable
is left open to allow for maximum flexibility. The pin assignments for the connectors
and the cables are as follows:
Pin Wire INPUT STIMULUS
A Black Signal + +
B White Signal - -
H Shield Driven Shield* Ground
D not used not used
E not used not used
NOTE: Pin H can be configured to be as a ground, rather than a driven shield. A
driven shield is used with the INPUT connector to minimize the effect of capacitance on
the cable, thus increasing common mode rejection. The shield is driven by a low
impedance source with a differential signal voltage from the amplifier. This driven
shield (the silver braid) should not be connected to ground, as this will cause
noise in the input signal. Instructions on how to convert pin H to a ground or shield
are detailed on the next page. Each channel can be configured independently.
The STIMULUS connector shield is connected to the system ground internally. Therefore,
any ground-referenced or isolated stimulator can be used with the STIMULUS connector.
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
5
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Configuring Pin H to be Shield or Ground
1) Determine if the channel is already configured as a ground or a driven shield. Using
a multimeter, set the meter to check for resistance. Measure between pin H and the front
panel ground connector. If the resistance is under 10 ohms, that channel’s pin H is set to
ground.
2) To convert the channel so that the braid is a ground, rather than a shield, remove
the cover, and look for two large capacitors on rear of the channel board. Near the
capacitors is a black jumper (J100). The jumper spans 2 of 3 pins on the connector on the
board. If the jumper is near the side marked GND, it is set to ground. If it is over to the
other side, it is a shield.
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
6
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Theory of Operation
Stimulus Mode
In Stimulus Mode, the INPUT connector is connected internally to the STIMULUS connector
to apply the stimulation signal to the electrode. All amplification circuits are grounded in
this mode, and the OUTPUT connector is disabled.
Record Mode
In Record Mode, the signal from the INPUT connector is coupled directly to the inputs of
a high impedance, low noise differential amplifier stage consisting of two operational
amplifiers with x10 gain. Direct coupling reduces the errors typically associated with
capacity input coupling. The operational amplifiers are in non-inverting mode and their
gain-setting networks connect through a common resistor to preserve high common-
mode rejection.
The common-mode voltage of the input signal at the inverting inputs of the operational
amplifiers is measured, and is used to drive the electrode cable shield. This improves
the common-mode rejection performance of the input amplifier stage. For this reason,
the driven shield should not be grounded.
The output signals are then connected to a second differential operational amplifier
circuit with a gain of x10. At this point, the differential electrode signal has been
amplified by x100 and converted to a single-ended signal with respect to ground. An
internal CMR potentiometer is trimmed at the factory to maximize the common-mode
rejection.
The signal passes through a double-pole low-pass filter, which attenuates frequencies
above the HIGH CUT-OFF switch setting. This stage provides no signal amplification.
If selected, the signal next passes through the Notch Filter. The Notch Filter is tuned
to the power line frequency and consists of a twin-T network in a feedback loop with an
operational amplifier. This stage does not amplify the signal.
The signal then passes through a double-pole high-pass filter, which attenuates
frequencies below the LOW CUT-OFF switch setting. Also included in this stage is
the final amplifier which provides x1, x10 or x100 gain to produce an output signal
according to the total gain specified by the GAIN switch.
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
8
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Specifications
Note: all specifications measured at +25 ° C
Noise
Voltage, fO= 10 Hz
Voltage, fO= 100 Hz
Voltage, fO= 1 Hz
Voltage, f
O
= 10 kHz
40 nV/Hz1/2, typical
15 nV/Hz1/2, typical
8 nV/Hz1/2, typical
6 nV/Hz1/2, typical
Voltage, fB= 10 Hz to 10 kHz 0.7 µV, rms, typical
Voltage, fB= 0.1 Hz to 10 Hz 1.6 µV, p-p, typical
Current, fB= 0.1 Hz to 10 Hz
Current, fB= 0.1 Hz to 20 kHz
Offset Voltage
15 fA, p-p, typical
0.8 fA/ Hz1/2, typical
Input offset voltage ± 0.3 mV, typical; ± 2 mV, maximum
Average drift ± 8 µ V/°C, typical; ± 15 µV/°C, maximum
Supply rejection
Bias Current
110 dB, typical
Initial bias current
Offset Current
± 3 pA, typical; ± 15 pA, maximum
Input offset current
Input Impedance
± 3 pA, typical; ± 12 pA, maximum
Input impedance
Inter-channel Crosstalk
1012Ω|| > 50 pF
Inter-channel Crosstalk
Voltage Range
90 dB @ 1 kHz
x 100 .11 VAC or .11 VDC ± 5%
x 1000 .011 VAC or .11 VDC ± 5%
x 10000 .0011 VAC or .11 VDC ± 5%
Common-mode rejection
(CMR)
Slew Rate
at least 75 dB
Slew Rate
Rated Output
2 V/µs
Voltage Output ± 11 V
Current Output 5 mA
Output Resistance > 5 Ω
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
9
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Low Cut-Off Filter
Cut
-
off frequencies
0.1 Hz,1.0 Hz,10 Hz,100 Hz, 300 Hz
Cut-off rate
High Cut-Off Filter
40 dB/decade
Cut-off frequencies 500 Hz,1 kHz, 5 kHz, 10 kHz, 20 kHz
Cut-off rate
Notch Filter
40 dB/decade
Frequency 60 Hz or 50 Hz, factory preset
Line rejection
Power
30 dB, typical
AC Power source 110 V, 60 Hz or 230 V, 50 Hz, preset
Power usage
Operating Parameters
> 3 W
Temperature 20°C to 40°C
Humidity
Physical Dimensions
20% to 75%
Width 17 inches (43.2 cm)
Height 4.75 inches (12.1 cm)
Depth 11.25 inches (28.6 cm)
Weight
19 pounds
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
10
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
Warranty and Service
LIMITED WARRANTY
What does this warranty cover?
A-M Systems, LLC (hereinafter, “A-M Systems”) warrants to the Purchaser that the Instruments manufactured by
A-M Systems (hereinafter the “hardware”), and sold after January 1, 2020, is free from defects in workmanship or
material under normal use and service for the lifetime of the hardware. Headstages manufactured by A-M Systems
and sold after January 1, 2020, will be repaired under warranty only once per year. This warranty commences on
the date of delivery of the hardware to the Purchaser. “Lifetime” is defined as the time all components in the
instrument can still be purchased from mainstream, common, electronic component distributors such as Digi-Key
Electronics, Newark, or Mouser Electronics.
For hardware sold prior to January 1, 2020, the warranty in effect at time of purchase applies, with the maximum
warranty period of three (3) years for new purchases, and one (1) year for those that have been repaired by A-M
Systems. For headstages manufactured by A-M Systems and sold prior to January 1, 2020, the maximum warranty
period is one (1) year.
What are the obligations of A-M Systems under this warranty?
During the warranty period, A-M Systems agrees to repair or replace, at its sole option, without charge to the
Purchaser, any defective component part of the hardware. To obtain warranty service, the Purchaser must return the
hardware to A-M Systems or an authorized A-M Systems distributor in an adequate shipping container. Any
postage, shipping and insurance charges incurred in shipping the hardware to A-M Systems must be prepaid by the
Purchaser, and all risk for the hardware shall remain with Purchaser until A-M Systems takes receipt of the
hardware. Upon receipt, A-M Systems will promptly repair or replace the defective unit and then return the
hardware (or its replacement) to the Purchaser with postage, shipping, and insurance prepaid by the Purchaser. A-M
Systems may use reconditioned or like-new parts or units at its sole option, when repairing any hardware. Repaired
products shall carry the same amount of outstanding warranty as from original purchase. Any claim under the
warranty must include a dated proof of purchase of the hardware covered by this warranty. In any event, A-M
Systems liability for defective hardware is limited to repairing or replacing the hardware.
What is not covered by this warranty?
This warranty is contingent upon proper use and maintenance of the hardware by the Purchaser and does not cover
batteries. Neglect, misuse whether intentional or otherwise, tampering with or altering the hardware, damage caused
A-M Systems 131 Business Park Loop, P.O. Box 850 Carlsborg, WA 98324
11
Telephone: 800
-
426
-
1306 * 360
-
683
-
8300 * FAX: 360
-
683
-
3525
E-mail: sales@a-msystems.com * Website: http://www.a-msystems.com
LIMITED WARRANTY, cont
by accident, damage caused by unusual physical, electrical, chemical, or electromechanical stress, damage caused
by failure of electrical power, or damage caused during transportation are not covered by this warranty. Further, no
guarantee is made regarding software compatibility with future updated operating systems. Products may not be
returned to A-M Systems for service, whether under warranty or otherwise, which are contaminated by infectious
agents, radioactive compounds or other materials constituting a health hazard to employees of A-M Systems
What are the limits of liability for A-M Systems under this warranty?
A-M Systems shall not be liable for loss of data, lost profits or savings, or any special, incidental, consequential,
indirect or other similar damages, whether arising from breach of contract, negligence, or other legal action, even if
the company or its agent has been advised of the possibility of such damages, or for any claim brought against you by
another party.
THIS EQUIPMENT IS NOT INTENDED FOR CLINICAL MEASUREMENTS USING HUMAN SUBJECTS.
A-M SYSTEMS DOES NOT ASSUME RESPONSIBILITY FOR INJURY OR DAMAGE DUE TO MISUSE OF
THIS EQUIPMENT.
Jurisdictions vary with regard to the enforceability of provisions excluding or limiting liability for incidental or
consequential damages. Check the provision of your local jurisdiction to find out whether the above exclusion
applies to you.
This warranty allocates risks of product failure between the Purchaser and A-M Systems. A-M Systems hardware
pricing reflects this allocation of risk and the limitations of liability contained in this warranty. The agents,
employees, distributors, and dealers of A-M Systems are not authorized to make modifications to this warranty, or
additional warranties binding on the company. Accordingly, additional statements such as dealer advertising or
presentations, whether oral or written, do not constitute warranties by A-M Systems and should not be relied upon.
This warranty gives you specific legal rights. You may also have other rights which vary from one jurisdiction to
another.
THE WARRANTY AND REMEDY PROVIDED ABOVE IS IN LIEU OF ALL OTHER
WARRANTIES AND REMEDIES, WHETHER EXPRESS OR IMPLIED. A-M SYSTEMS
DISCLAIMS THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR USE, WITHOUT LIMITATION.
A-M Systems Model 1700 Manual DRW-5026300 rev 11
Revision History
Rev Date Description
66/30/06 Initial Document Control release
74/28/10 DCR201200. New warranty info, and company name
89/19/16 DCR 202463. Remove calibration instructions.
95/15/18 DCR 203014. Update driven shield information
10 1/18/19 DCR 202615. Review content. Add rev control to content
11 3/19/20 DCR 203316. Update warranty.
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