Guide
to
Electrophysiological
Recording
Headstage
Connection
The
threaded
white
socket
is
the
microelectrode
input.
The
connection
between
the
microelectrode
and
this
socket
should
be
kept
as
short
as
possible.
Ground
Output
Connector
(Gold)
The
gold
ground
socket
of
the
CHANNEL
1
headstage
is
the
signal
ground
and
is
used
for
grounding
the
preparation.
Using
this
connection
as
the
preparation
ground
minimizes
hum.
Interchangeability
Any
unity
‐
gain
headstage
in
the
HS
‐
9A
series
can
be
used
for
CHANNEL
1
or
CHANNEL
2.
The
headstages
should
not
be
exchanged
while
the
Axoclamp
900A
is
switched
on.
Cleaning
To
clean
salt
spills
from
the
input
connectors
wipe
with
a
damp
cloth.
Avoid
spilling
liquids
on
the
headstage.
Input
Leakage
Current
All
DC
‐
connected
systems
suffer
from
the
problem
of
drift.
With
changes
in
temperature
and
the
passage
of
time
the
DC
transfer
functions
of
all
semiconductor
devices
can
drift
by
many
millivolts
away
from
their
initial
values.
The
major
worry
in
a
microelectrode
system
is
that
the
cumulative
effects
of
drift
in
various
parts
of
the
circuit
may
lead
to
the
development
of
a
DC
offset
across
the
resistor
(R
0
)
used
to
set
the
H
value.
As
a
result,
an
undesirable
DC
leakage
current
is
injected
into
the
microelectrode.
Careful
consideration
of
this
problem
has
been
applied
throughout
the
design
of
the
Axoclamp
900A
and
the
overall
DC
offset
has
been
made
as
insensitive
as
possible
to
the
drift
in
the
integrated
circuits.
As
well,
special
low
‐
drift
integrated
circuits
have
been
used
in
all
critical
positions.
The
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