Pass Laboratories XP-10 User manual

November 18, 2010 Rev 1.02 1
PASS®
XP-10 Owner’s Manual

November 18, 2010 Rev 1.02 2
For your protection please read the following:
Water and moisture: Electrical devices should not be used near
water (as per example, near a bathtub, washbasin, kitchen sink,
laundry tub, wet basement or swimming pool ). Care should be taken
such that objects do not have the opportunity to fall, and that liquid is
never spilled onto or into the device enclosure through openings.
Power Sources: An electrical device must be connected to a mains
power source in strict accordance with the supplied product owner’s
manual. Please verify that the AC mains voltage specified in the
product manual matches those requirements indicated on the unit and
the AC voltage provided to your location by the power company.
Grounding: Adequate precautions should be taken so that the
grounding provisions built into an electrical product are never defeated.
Power Cords: Pass Laboratories provides a power supply cord that
meets all legislated requirements for the market in which the product
was originally sold. If you choose to substitute an after-market product
we urge you to choose one that is fully safety rated by the necessary
local authority.
Power Cord Protection: Power supply cords should be routed so that
they are not likely to be walked on, abraded, or pinched by items
placed on or against them, paying particular attention to cords where
they enter plugs or exit from a device. Never under any circumstance
insert a cut or damaged power cord into a mains power socket.
Power and Signal: Cables should never be connected / disconnected
with equipment powered up. Failure to heed this warning may damage
or destroy equipment.
Ventilation: Power-amplifiers run hot, but you should be able to place
your hands on them without discomfort. You must allow for this heat in
installation, by providing for free air circulation around the product.
Electronics should not be subjected to sources of excessive radiant
heat. Excessive heat can shorten the life of the product and may cause
the electronics to self-protect and shut down.
Servicing: To reduce the risk of fire, electrical shock or other injuries,
the user should not attempt to service the device beyond that which is
described in the operating instructions. All other servicing must be
referred to qualified service personnel.

November 18, 2010 Rev 1.02 3
Introduction
The XP-10 is an ultra high quality line-stage audio preamplifier
featuring remote control and internal power supply. The XP-10
minimizes the number of components in the signal path, and yet
retains exemplary objective performance specifications. It pushes the
state of the art by exploring how much subjective quality is obtainable
with unique circuit elements applied in innovative ways.
The Pass Laboratories XP-10 along with the XP-20 pre-amplifiers are
the natural descendants to the highly acclaimed and successful X
series of Pass Laboratories line-stages represented by models X0.2,
X1 and X2.5.
The X series pre-amplifiers have received many highly respected and
well-deserved accolades over the past 11 years…. justifiably so. More
importantly they have provided a solid foundation from which the
current and newest product has evolved.
These new pre-amp offerings from Pass Laboratories objectively
sound and measure significantly better than their immediate
predecessors.
The new XP series pre-amplifiers are more true to state of the art
recordings than our previous line level product. Given quality
recordings, these pre-amplifiers sound more dynamic, bass lines are
more clearly, cleanly, and accurately delineated, helping eliminate un-
necessary one note bass; instruments and voice are presented in a
more refined spatial envelope, and with better spectral balance.

November 18, 2010 Rev 1.02 4
Fine nuances and details, which frequently have gone un-noticed, now
become apparent -- even in loud and highly complex musical
passages.
The simple truth is that a decade of knowledge and experience gained,
coupled with new component technology, has enabled both enhanced
performance and listening satisfaction over the building blocks we had
available when the original X series pre-amplifiers came to market.
Pass Laboratories has not been shy about taking advantage of these
circuit innovations and new components in these new pre-amplifiers.
You will hear, and appreciate, these significant sonic improvements as
you experience the XP series product.
Collectively, audiophiles tend to listen quite a bit differently today, than
they did when the original X preamps were created, and the XP line of
product have all been designed to reflect those changes in listening
style.
Pass Laboratories has redesigned the remote control to allow direct
access to the most frequently wanted control functions, thus simplifying
and enhancing product operation. The new remote control codes have
been carefully selected to minimize the impact on other remote
controlled electronic devices, allowing for more carefree product
placement.
Volume control steps on the new pre-amplifiers are more numerous
and generally of smaller increments, giving the listener a wider choice
of listening levels to better accommodate the wildly-fluctuating levels of
current, verses legacy, recordings.

November 18, 2010 Rev 1.02 5
Changing lifestyles dictate that many audiophiles now share family
space where music may be an adjunct to other activities. To better
serve the needs of these listeners, these new pre-amplifiers allow for
significantly more precise volume steps and greater attenuation at the
very lowest volume levels.
So that these very low-volume listening levels have real world
practicality, the noise floor and very fine detail retrieval of these new
pre-amplifiers is dramatically superior to our previous product.
Frequently, the perception of increased detail comes at the cost of
equally increased grain or edginess in the music. With this new pre-
amplifier, hundreds of hours of thoughtful listening and careful
adjusting have produced a product where the enhanced detail simply
comes through as greater spatial refinement and dynamic accuracy;
without any loss of musicality. Bass definition is better than in
pervious models, highly dynamic passages typically have more weight,
a more accurate leading edge with increased control and the spectral
balance is more finely integrated top to bottom.
We sincerely believe these are simply the best pre-amplifiers Pass
Laboratories has ever built! Thank you for giving us the opportunity to
prove this claim.
ADVISORY
There is an Extremely Small (but Non-zero) Chance That, Through a
Process Know as Tunneling, This Product May Spontaneously
Disappear from Its Present Location and Reappear at Any Random
Place within the Universe, Including Your Neighbor's Domicile.

November 18, 2010 Rev 1.02 6
The Manufacturer Will Not Be Responsible for Any Damages,
Inconvenience or Mental Anguish That May Result From These
Spacetime Perturbations.
There is a much higher probability that when you first plug your new
pre-amp into the wall and listen that you will not be experiencing the
full measure of performance this product is capable of. These are high
bias Class A topology circuits and their performance is largly
temperature dependendt. We expect these circuits to heat up slowly
through normal operation, do not attempt to augment that heating by
any artificial means. Temperature and performance will slowly
stabalize over the first 24 hours of operation and thereafter will be at
their sonic best. Be aware however that if you unplug or otherwise
remove power from the unit that the warm up period starts afresh.
Please give this product at least 24 hours initial warm up time
before attempting any critical listening.
Like virtually all modern digital product, there is no “off” in the
traditional sense. The XP preamps are quite “Green” a typical current
draw for this product is 10 watts; they are designed to be powered up
100% of the time.
SET-UP AND OPERATION
So much for the philosophy, physics and advantages, lets play music.
Please read and understand the operational instructions and safety
issues associated with this product. We go through great effort to
make a soundly engineered, and supurbly performing product of
lasting duribility.

November 18, 2010 Rev 1.02 7
We understand that things infrequently go wrong, if you have any
questions or problems please contact either your dealer or the factory,
we are here to support the product and you, the user.
As with all audio electronics the power cable should be the last thing
attached and the first one removed any time you hook up or remove
equipment from the signal chain.
The preamplifier has five sets of stereo input connections, both single-
ended and balanced output connections and a full function remote
control in addition to the normal complement of front panel control
functions.
The preamplifier's voltage and current rating are indicated by affixed
tag on the rear of the preamplifier. This tag will indicate 240 volts, 220
volts, 120 volts, or 100 volts. A 1.0 amp 3AG slow blow fuse is
provided with 100-120 volt units, and a 0.5 amp slow blow fuse is
provided with 220-240 volt units. The input frequency rating of the
power supply is 50 to 60 Hz. The preamplifier typically draws 10 watts
during operation. Please verify that the indicated voltage requirement
of this preamplifier is consistent with the utility voltage at your location.
We have provided a standard IEC AC power cord that fits into the IEC
320 line receptacle at the rear of the preamplifier chassis. The
preamplifier is equipped for operation with an earth ground provided by
the users AC outlet. Do not defeat this ground. The chassis and
circuit ground of the preamplifier are isolated from one another through
a power thermistor, and bonded to earth through the chassis which
gives a ground connection for safety but helps avoid ground loop
related noise issues.

November 18, 2010 Rev 1.02 8
There are a total of five inputs. Two of the five inputs are balanced
XLR only. The other three inputs are single-ended only. There are
two pairs of outputs available with identical gain structure. One pair
Balanced, one pair single-ended.
Balanced inputs and outputs are via XLR connectors. Single-ended
inputs and outputs are via RCA connectors. On the XLR connectors,
pin 1 is grounded, pin 2 is the positive signal, and pin 3 is the negative
signal. Left channel RCA connectors are marked with "L". Right
channel RCA connectors are marked with "R". In a similar fashion
balanced XLR inputs and outputs are marked with "L" for left and "R"
for right channel.
The main outputs are located at the left-hand side (viewed from the
rear) of the rear panel, two male XLR connectors, and two RCA
connectors, "R" (right) and "L" (left). The RCA connector's ground is in
parallel with pin 1 of the XLR outputs and the RCA hot is fed from an
independent summing junction that maximizes the X circuit benefits.
The RCA, single-ended, outputs are buffered from the balanced
outputs. You may use both the single ended and balanced outputs at
the same time. On the XLR, pin 1 is ground, pin 2 is positive, and pin
3 is negative.
Description of Operation
In application the XP-10s front panel controls and alphanumeric
display are quite straight forward, and intuitive. We encourage you to
become familiar with their operation prior to establishing any input
connections with this unit.

November 18, 2010 Rev 1.02 9
Experience indicates that engaging in a few minutes of exploration will
add much to your ultimate enjoyment of this exceptional Pass Labs
product.
The left most button on the front panel is Mute. Pressing this button
toggles between mute on and mute off. Mute on removes signal from
the output of the preamp.
The front panel mode switch cycles the preamplifier display through 2
different levels and off. These two functions are as follows: Bright, Dim
and Off. Using any functions with the display “off” will momentarily
bring the display back up to its dim setting.
The two Select switches (designated by left and right pointing arrows)
then alter the displayed active input, 1 through 5.
Input 5 is unique in that it is linked with the Home Theater (Unity Gain)
function. (The HOME THEATRE FUNCTION is discussed at length
later in this manual.) The two select arrows logically control selections
of the various inputs to the preamplifier.
The theater pass through function bears special attention, this function
is only available as direct access through the hand held remote control.
This function is associated only with input number 5 and has two
positions selected with the “pass thru” button on the 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.

November 18, 2010 Rev 1.02 10
When the right-front and left-front outputs of the processor are routed
through input 5 of the XP-10 (with the gain of the XP-10 set for Unity),
the volume will be under full control of the processor and the XP-10's
action will be totally transparent. When the user chooses this setting
the software sets the XP-10's gain to the unity gain setting, regardless
of how it was previously configured. When at Unity both left and right
level controls on the XP-10 will have a displayed value of 75 (0 dB),
and any previous balance settings will be set-aside into a temporary
registry. 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 selecting low gain and setting
the volume at step 75.
Before selecting the theatre pass through (pass thru) option, it is
imperative that the input device on input number 5 has its gain set to
some minimum level. Failure to follow this precaution could result in a
volume level intolerable to both ears and speakers.
We have designed this product, so that the volume setting of the
preamplifier will always revert to the values in the temporary register as
you exit from Pass Through. With the rarest of exceptions this is a
very safe transition, very infrequently will the normal chosen level be
higher than 0 dB.
The electronic volume control allows greater than 70 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 volume control, assuring precise level steps and high
common mode rejection in balanced circuits.

November 18, 2010 Rev 1.02 11
Wayne Colburn's exceptional volume control in conjunction with the
fluorescent display gives the user ability to replicate volume levels with
absolute accuracy in steps of roughly 1 dB.
The remote control uses 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
your Pass Laboratories XP-10.
The Remote control operation is, or should be very intuitive in
operation; we have attempted to make its operation as familiar as
possible. Where applicable the remote mirrors the front panel controls.
Power, tape and ext. amp on (external amplifier turn-on) have no
reality with the XP-10. These specific control functions have no effect
on this product.
MUTE: pressing mute once will quiet the pre-amplifier outputs;
pressing mute a second time will return you to the previous volume
control setting
INPUT SELECTION: Pressing. 1,2,3,4,5 will immediately move the
input selection to that input selection; volume and balance settings will
not be disturbed.
BALANCE: Pressing balance left (<) or balance right (>) will increase
the level in the left or right speaker, depending upon which button is
pushed.
VOLUME: Pressing the increase (^) button or the decrease (v) button
will shift the volume setting 1dB, holding a button down will increase or
decrease the level until such time as you either release pressure on
the button or reach the limits of the volume control.

November 18, 2010 Rev 1.02 12
PASS THRU: Pushing this button twice, sets the pre-amplifier to it’s 0
dB gain setting, indicating volume step 75 (0 dB) and input 5. We have
intentionally made this command a two-step operation such that you
will not accidentally select this command with its associated high
volume. Pressing the button once will bring up the question of “YES”
on the display. If you are sure that you wish to access the pass
through function, press the button a second time. There is a time out
built into this command sequence. If you do not confirm the “pass thru”
command within 7 seconds then the command sequence aborts and
the XP-10 resorts to its previous status.
DISPLAY: The default setting for the display is “bright”, pressing the
display button once changes the display to its “dim” or “low intensity”
setting, pressing the button a second time selects “off” for the display.
When “off” is selected any other control function will cause the display
to indicate product operational status for approximately 7 seconds and
then the display will once again blank. Pressing the display button a
third time cycles back to a “bright display”
Design Comments
We recommend the use of the balanced output mode where possible.
Balanced input to power-amplifiers will typically retain the character of
the input mode, but offers less distortion, less noise, more gain, and
more voltage swing, without compromising the sound.

November 18, 2010 Rev 1.02 13
With balanced operation, the common mode rejection of the preamp
reflects the intrinsic common mode rejection of the topology, the
matching of the gain devices, and the matching of the attenuator
channels. In this case we have been able to keep the total mismatch
to about .1%, for a common mode rejection of approximately -60 dB.
The input system of the preamplifier will exhibit full common mode
noise rejection with passive balanced sources, where the negative
input is connected to ground at the source through the appropriate
source impedance. This allows adaptation of unbalanced sources to
balanced operation with passive cable connections in a manner that
achieves the noise rejection of active balanced sources.
The use of a micro-controller allows all of the preamplifier functions to
be repeatable and accurately controlled. The micro processor only
controls the functions of the preamplifier. At no time does any of the
input or output signal come into contact with the digital control signals.
The digital circuits are powered by a power supply that is isolated from
the analog supply. Should it ever be necessary to update the software
that controls the functioning of the preamp only the socketed micro
processor need be changed.
Muting relays, which delay connection during turn-on and shut off the
output when insufficient power supply is available to maintain
regulation, guard the output of the preamplifier and offer protection to
the power-amplifier and loudspeakers.
The XP-10 consists of a single chassis.

November 18, 2010 Rev 1.02 14
SPECIFICATIONS
Gain selection 83 steps
Overall Gain -73 dB to +10 dB
Frequency Response -3dB @ 2 Hz and 60 kHz
Input Impedance 96 k ohm balanced
48 k ohm single ended
Output Impedance 1000 Ohm balanced
150 ohm, single ended
CMRR -60 dB, 1 kHz
Cross-talk -90 dB, 1kHz Ref 1V
Signal to Noise Ratio < -110 dB, Ref 5V
Power Consumption 10 watts
Dimensions, Chassis 17”W x 12”D x 4”H
Shipping Weight 32 pounds in packing carton

November 18, 2010 Rev 1.02 15
Pass Warranty
Rev 1 of
August 11, 2008
Please check with the factory authorized distributor in the country
where you are purchasing this product for specific warranty
information.
All Pass Laboratories products purchased new from an authorized
Pass Laboratories dealer in North America are covered by a
transferable, limited 3-year warranty. This warranty includes all parts
and labor charges incurred at the factory or factory specified repair
facility, exclusive of any subsequent or consequential damages.
Damage due to physical abuse is specifically excluded under this
warranty.
For this warranty to apply the customer is responsible for returning the
product unmodified to the factory within the specified warranty period.
The customer assumes all responsibility for shipping and insurance to
and from the factory or a factory specified repair facility. The conditions
and stipulations of this Pass Laboratories warranty only applies to units
originally sold new through an authorized dealer. Warranty on factory
repair is 60 days and covers only the scope of the original repair.
Non-North America customers should consult with their original Pass
Labs dealer or distributor for warranty repair instruction prior to
contacting the factory or shipping product to the factory for repair.
Non-North American product must be returned to the country of origin
for warranty service. Foreign distributors are only required to offer
warranty service on Pass Laboratories product that they have
imported, verifiable by serial number.
Please note: Conditions of warranty service and customer rights for
product purchased outside the United States may vary depending
upon the distributor and local laws. Please check with your local
distributor for specific rights and details.

November 18, 2010 Rev 1.02 16
Any modifications to Pass Laboratories products that have not
received written factory approval nullify all claims and void all
provisions of the warranty and liability by the maker or authorized
distributor. Should a modified product be returned to the factory for
repair the owner will be required to pay all necessary charges for the
repair in addition to those charges required to return the product to it’s
original configuration.
In the case of safety issues, no product shall be returned to the
customer without those safety issues being corrected to the most
recent accepted standards.
Removal or alteration of original Pass Labs serial numbers voids the
factory warranty. Product with altered or missing serial numbers will be
suspect as counterfeit or stolen product.
Pass Laboratories will not repair or in any way indemnify any
counterfeit or cloned product.
Pass Laboratories does not offer products in voltages intended for
international markets either to authorized Pass Labs dealers or to third
parties located in the United States or Canada.
For more information please contact: Pass Laboratories Inc.
© 2008 Pass Laboratories Inc..
“Pass ”,“pass ”,“Pass Labs ”,“Pass Laboratories ”, Supersymmetery
”,“Aleph ”,and “Zen ” are all registered trademarks of Pass
Laboratories, Inc., and law thereto protects all rights.

November 18, 2010 Rev 1.02 17

November 18, 2010 Rev 1.02 18
PASS
PASSPASS
PASS
Pass Laboratories
P.O. Box 219, Foresthill, CA 95631
Voice: 530.367.3690 – Fax: [phone]
www.passlabs.com
“Pass”, “PASS”, ”Pass Labs”, ”Pass Laboratories”, “Supersymmetery”, “Aleph”, and “Zen” are
all registered trademarks of Pass Laboratories, Inc., and law thereto protects all rights.