ExAmp-20KS Extracellular Spike Amplifier
User guide
The ExAmp-20K is an AC-coupled spike amplifier
designed for low-noise extracellular recording from
single- or multiple units. Its unique headstage probe
design puts the first stage of amplification at the
microelectrode interface, resulting in less external
interference noise pickup. The built-in filters are
optimized for solid-conductor microelectrodes such
as carbon fiber, tungsten or stainless steel. The
included 60 Hz (or 50 Hz, selectable) reject filter and
our special electrode holder adapters virtually elimi-
nate the need for Faraday cages. Front and rear panel
controls are intentionally simplified for ease of use
without compromising the quality of recordings.
The positive input of the front amplifier (center pin
of the headstage’s SMA receptacle) is referenced to
the ground (ground socket) providing high-quality,
single-ended (monopolar) recordings. The ExAmp-
20K can be used for research and teaching purposes
only that do not involve human subjects.
Main unit specifications
Input impedance:
10
13
Ω
Input bias current:
2 pA
System gain:
200x to 20,000x in 7 calibrated steps
System noise:
> 2.5
µ
V peak to peak with probe input grounded
Bandpass filter:
300 Hz to 8000 Hz, built-in Butterworth 4-pole
Notch filter:
50/60 Hz, selectable inside the box
Output voltage swing:
±10 V, maximum
Power source:
External, 12 VDC power supply
Power consumption:
200 mA, maximum
Amplifier (Gnd) ground:
Isolated from DC input ground (Case)
Dimensions:
155 x 54 x 175 mm aluminum box
Weight:
1.35 lb (614 grams)
Front panel view
Power:
Turns the unit on or off. Red LED signals
on status
Probe:
Inputs the plug of headstage probe
Gain:
Selects the magnitude of amplification
from 200x to 20,000x in 7-positions
Offset:
Offsets the output signal by +/- 1V, max.
Polarity:
Changes the polarity of output
Output:
BNC jack out-putting amplified signal
Front panel controls
General description
Rear panel view
Color of parts may vary
Kation Scientific, LLC, P.O. Box 14674, Minneapolis, MN 55414 Phone/Fax: (651) 698-5167.
E-mail: [email protected] Web site: www.kationscientific.com
Headstage probe
Signal amplification:
10x, single-ended, AC-coupled
Mounting rod diameter x length:
1/4" (6.35 mm) x 4" (105 mm)
Body diameter x length:
0.75" (19 mm) square x 2.05" (52 mm)
Material:
Nickel-plated brass
Cable length:
52" (132 cm)
Input receptacle:
SMA, spark plug type, gold-plated
Input & ground sockets mate with: 0.0315"-0.0370" (0.80-0.95 mm) diameter
male pins
Power In:
Two identical DC power jacks for
12 VDC input and output,
2.1 mm x 5 mm type
Gnd:
Circuit ground, galvanically isolated
from ‘Power In’ ground (Case),
2.64 mm banana jack
Case:
Ground (0V) of 12 VDC power input
2.64 mm banana jack
Back panel objects
This exceptional headstage probe is an electrode
holder in one. Using appropriate holder adapters, all
Kation-made microelectrodes or third-party standard
metal electrodes can directly be plugged into the
probe. There is no need for additional electrode hold-
ers. See next page for details.
Also, the coaxial arrangement of the mounting rod
and the SMA-type electrode input receptacle allows
an easy yet precise positioning of the recording elec-
trode. The robust, nickel-plated body of the probe
provides and unsurpassed protection from electro-
magnetic interference.
Mounting rod
Cable
Electrode input
Ground
SMA receptacle
