Home Theater System User Manual

8
XP-20 Owner’s Manual
remote; those two positions, on and off. This function is useful in
that it allows the preamplifier to function as a unity buffer (0dB gain
at volume step 75) for use with components that best function with
their own volume controls, such as surround processors. When
the right-front and left-front outputs of the processor are routed
through input 5 of the XP-20 (with the gain of the XP-20 set for
step 75), the volume will be under full control of the processor and
the XP-20’s action will be totally transparent.
When the user chooses this setting the software sets the XP-20’s
gain to step 75 and displays the setting as 75P for both right and left
channel, regardless of how it was previously configured. When at
unity gain in the home theater mode (Pass Thru) both left and right
level controls on the XP-20 will have a displayed value of 75P (0
dB), and any previous balance settings will be over written, allowing
total control by the processor. Both of these default conditions are
intentional, and intended to make the most advantageous use of your
source electronics.
You may also set any input to unity (0 dB) by setting the volume at
step 75 from the remote or front panel control.
When “Pass Thru” is de-selected the XP-20 reverts back to the
previous input, volume and balance settings.
Input 5 may be manually selected and used without the “pass thru”
function, in which case its behavior will be identical to inputs 1-4.
The electronic volume control allows greater than 80 dB range and is
driven by a micro-controller that reads the optical encoder serving as
a front panel volume control.
In this manner tracking of the volume of the two balanced channels
is possible with accuracy unavailable on any ordinary analog volume
control, assuring precise level steps and high common mode noise
rejection in balanced circuits. Wayne Colburn’s exceptional volume
control in conjunction with the fluorescent display give the user
ability to replicate volume levels with absolute accuracy in steps of
roughly 1 dB or less.
The remote control uses a multi-button direct access architecture.
This remote is designed to operate several pieces of Pass Labs
electronics, not all of the functions available on this remote will be
applicable to all of your Pass Laboratories electronics. Specifically
the uppermost left hand button marked “power” does not work with
the XP-20. The XP-20 is designed to be powered continuously and
therefore this button will not affect the pre amplifiers operation.