Supplied loading values:
• 100 ohms
• 200 ohms
• 1k ohms
• 47k ohms
Supplied gain values:
• 45 dB
• 50 dB
• 55 dB
• 60 dB
CONFIGURATION
INDICATORS
Front panel indicators
show the status of the power
management circuit. When a music signal is detected,
both green lights will illuminate, indicating that the unit
is operating properly. Within a fraction of a second,
the Ph.D. is powered-up and stable.
Every 30 minutes, the yellow light will briefly illuminate,
indicating that the unit is checking for a continuing musical
signal. If a signal is detected, power is extended for an
additional 30 minutes.
The red lights indicate that the batteries are running low.
If you want loading or gain values that are not included
in these stock values, blank configuration boards and
custom configured boards are available.
Conventional designs use inexpensive, low-quality
computer rocker switches. Their design is inadequate
for configuring the low-level signal from a phono
car tridge. To offer the user a wide range of
configurations while maintaining signal integrity,
the Ph.D. incorporates a unique plug-in configuration
circuit board.
Each channel of the Ph.D. has two configuration
boards:
One to select cartridge loading and a second
to select gain. Each board is square, and each side
of the square has an associated configuration value.
Settings are easily adjusted by unplugging the board
and rotating it to the desired value. This approach
gives the highest-quality connections with the
shortest and most direct signal path. The correct
orientation that the configuration board is set
at is indicated by reading the board when you
are facing the front of the Ph.D. unit. It will
be the only number that is readable or
right-side-up.
The Sensitivity Control
sets the threshold of the
signal monitor. It is set at the midpoint when shipped.
Since there is quite a variance in the output voltage of
phono car tridges, some adjustment may be necessar y.
If the Ph.D. sometimes turns itself on when there is
no musical signal, reduce the monitor sensitivity by
turning the control clockwise. If the Yellow light stays
on while music is playing, increase the monitor
sensitivity by turning the control counterclockwise.
NOTE:
This control does not affect the audio circuit.
Location of two configuration boards and sensitivity control.
sensitivity
control
The Ph.D. is built within a 12-gauge steel case for extreme
levels of rigidity and magnetic shielding. To maintain signal
integrity, the Ph.D. uses a gold-plated printed circuit board
that provides a lifetime of undiminished performance.
The physical component design uses a dual mono layout
so that each channel sees the same signal path, thus
enabling subtle gain and phase balance between channels.
The Ph.D.’s signal path is built upon experience derived
from the Sutherland PH-2000 and the AcousTech PH-1P
(both Stereophile Class A components). Refinements
were made to reduce the noise level in the established
musicality of those designs.
CONSTRUCTION
The rear panel includes inputs, outputs and a ground
lug, as well as the LED indicator guide and instructions
for removing the Ph.D.'s cover.
