Preface
Please take the time to carefully read this instruction
manual prior to installation or use of your PH5 phono
preamplifier. Because it is a highly advanced electronic
instrument, there are several facts and procedures you
should know before you place it in operation.
Just as you would not purchase and attempt to operate an
expensive camera, computer system or high-performance
automobile without first learning something about perfor-
mance parameters and correct operating procedures, so too
your phono preamplifier requires some familiarization
before you make it part of your music reproduction system.
Your reward, in terms of maximum performance and a long
service life, will be well worth the effort.
Warnings
1.
To prevent fire, or shock hazard, do not expose your PH5
to rain or moisture.
2.
This unit contains voltages which can cause serious
injury or death. Do not operate with cover removed.
Refer servicing to your authorized Audio Research dealer
or other qualified personnel.
3.
The power cord on your PH5 is equipped with a stan-
dard three-prong grounding plug. For absolute protec-
t i o n ,
do not defeat the ground power plug.
This pro-
vides powerline grounding of the PH5 chassis to provide
absolute protection from electrical shock.
4.
For continued protection against fire hazard,
replace the fuse only with the same type and
rating as specified at the fuse holder.
DO NOT ATTEMPT TO OPERATE THIS
EQUIPMENT BEFORE INSTALLING THE VACUUM
TUBES IN THEIR PROPER SOCKETS.
Packaging
Save all packaging in a dry place away from fire
hazard. Your PH5 phono preamplifier is a precision elec-
tronic instrument and should be properly cartoned any
time shipment is made. You may not have occasion to
return your unit to the factory for service, but if that should
prove necessary, or other occasion requiring shipment
occurs, the original packaging will protect your PH5 from
unnecessary damage or delay.
Note that your PH5 has been shipped with the vacuum
tubes installed in a protective foam block under the top
cover. With the PH5 unplugged, use a phillips-head screw-
driver to loosen the fastening screws, remove the top cover
and set aside. Install the numbered tubes in their respective
sockets, refasten the top cover and store the foam block
with your carton.
Front Panel Controls
POWER ON / O F F :
The unit is off when no front panel
LEDs are lit; unit defaults to “off” whenever it is unplugged
and then plugged in. Press the Power switch to turn unit
on; after approximately 30 seconds the mute LED will stop
flashing and stay on continuously (along with the power
LED and chosen cartridge loading LED) indicating unit is
ready to play.
MUTE:
After unit is on and warmed up for at least 30
seconds, the unit defaults to mute position indicated by
continuously lit mute LED. Pressing the Mute switch once
so the mute LED is unlit unmutes the PH5 for play; press-
ing the Mute switch again lights the mute LED and mutes
the PH5.
MONO:
Pressing the Mono switch selects between stereo
and mono operation; when mono LED is lit, the PH5 is in
mono, when unlit it is in stereo.
L O A D :
Pressing the load switch allows the user to step
through five pre-set cartridge loading options (47K, 1000,
500, 200, and 100 ohms) with the LED lit above the cur-
rently selected load value for listening. It is suggested that
you select the loading value option nearest the cartridge
manufacturers loading recommendation to begin with and
then listen to alternate loading if desired.
Because all four PH5 front panel functions are duplicated on
the remote, you may listen to loading sonic changes from
the listening position by repeatedly pressing the Load
button to scroll through the values. (Note that volume level
will decrease as lower loading values are selected.)
Model PH5
1
1
TUBE LOCATIONS
TOP VIEW
REAR
FRONT
V 1
V 2
V 3
V 4
