USE
WITH
A
PSX
‐
R
©
Cyrus
Audio
Ltd
Jun
2014
16
Cyrus
6
DAC,
Cyrus
8
DAC
service
manual
Issue
1
Use
with
a
PSX
‐
R
When
a
PSX
‐
R
power
supply
is
connected
to
a
Cyrus
8
DAC,
the
presence
of
power
as
the
PSX
‐
R
is
switched
from
standby
automatically
disconnects
the
feed
from
the
internal
power
supply
to
the
preamplifier
regulators
(via
switch
transistors
T406/T402).
The
power
from
the
PSX
‐
R
is
then
fed
to
the
preamplifier
regulators
via
D451/D454.
No
modification
is
necessary
to
the
amplifier
for
use
with
a
PSX
‐
R,
it
may
be
connected
without
any
changes
to
the
amplifier.
The
connections
between
the
amplifier
and
PSX
‐
R
function
as
follows
‐
Pin
1
(Standby)
This
is
an
output
from
the
amplifier
to
send
a
standby
control
message
(logic
1,
+5V)
to
the
PSX
‐
R,
enabling
the
regulated
power
supplies
of
the
PSX
‐
R.
Note
that
this
pin
will
not
change
state
if
the
amplifier
detects
a
fault
(See
pin
5).
Pin
2
(Positive
supply)
In
Cyrus
8
DAC
amplifiers,
this
pin
delivers
+18V
from
the
PSX
‐
R
to
the
amplifier,
switched
by
the
Standby
control
system.
Pin
3
(GND)
This
pin
is
the
system
ground
return
between
the
amplifier
and
PSX
‐
R.
Pin
4
(Negative
supply)
In
Cyrus
8
DAC
amplifiers,
this
pin
delivers
‐
18V
from
the
PSX
‐
R
to
the
amplifier,
switched
by
the
Standby
control
system.
Pin
5
(PSX
‐
R
detect)
This
pin
is
an
input
to
the
amplifier
to
detect
the
presence
of
a
working
PSX
‐
R.
The
pin
also
sets
the
working
mode
of
the
PSX
‐
R.
T408
and
associated
components
act
on
the
line
to
set
a
reference
voltage
that
switches
the
PSX
‐
R
to
variable
mode,
set
for
18V
supply.
This
diagram
shows
the
pin
numbers
of
the
power
supply
input
connector
on
the
amplifier.
View
is
of
the
connector
pins
from
the
rear
of
the
amplifier
