Pass Laboratories XP-10 User manual

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XP-10 Owner’s Manual
passTM
XP-10 Owner’s Manual
Dec 4, 2009

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XP-10 Owner’s Manual
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 edge 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.
The new XP series pre-amplifiers are more true to state of the art
recordings than our previous 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. Fine nuances and
details, which frequently go 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 in 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.
Introduction

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XP-10 Owner’s Manual
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.
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 the finest pre-amplifiers Pass
Laboratories has built to date, without question!
Thank you for your purchase of the XP- 10.

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XP-10 Owner’s Manual
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.
The Manufacturer Will Not Be Responsible for Any Damages,
Inconvenience or Mental Anguish That May Result.
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 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.
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. 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’s voltage and current rating are indicated by affixed
tag on the rear of the preamplifier. It will indicate either 240 volts,
220 volts, 120 volts, or 100 volts. A 0.5 amp 3AG slow blow fuse
is provided with 100-120 volt units, and a 0.25 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
ADVISORY
Set-up

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XP-10 Owner’s Manual
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 is connected to earth through a
power thermistor, which gives a ground connection for safety but
helps avoid ground loop related noise issues.
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.
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. 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.
Description of Operation

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XP-10 Owner’s Manual
The front panel mode switch cycles the preamplifier’s display
through 3 different brightness levels.
The left right arrows select inputs 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 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-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 at Unity both
left and right level controls on the XP-10 will have a displayed value
of 73, and any previous balance settings will be lost. 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 by setting the volume at step 73.
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
minimum. Failure to follow this precaution could result in a volume
level intolerable to both ears and speakers. To further protect
your hearing and valuable audio equipment, we have designed this
product, so that the volume setting of the preamplifier will always
revert to zero as you change inputs from Pass Through to any other
input.
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 volume control, assuring precise level steps and
high common mode 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.

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XP-10 Owner’s Manual
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 your Pass Laboratories XP-10.
The Remote control operation is, or should be very intuitive in
operation; we have attempted to make it’s 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.
PASS THRU: Pushing this button twice, sets the pre-amplifier
to volume step 73 and input 5. We have intentionally made this
command a two step operation such that you will not accidentally
select this command with it’s 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 it’s previous status.
DISPLAY: The default setting for the display is “bright”, pressing
the display button once changes the display to it’s “dim” or “low
intensity” setting, pressing the button a second time selects “off ”
for the display. When “off ” is selected any other control function

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XP-10 Owner’s Manual
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”
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.
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.
Design Comments

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XP-10 Owner’s Manual
For more information please contact:
Pass Laboratories Inc.
P.O. Box 219,
24449 Foresthill Rd.,
Foresthill, CA 95631
Tel: [phone]
Fax: [phone]
www.passlabs.com
© 2008 Pass Laboratories Inc.

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XP-10 Owner’s Manual
“Pass”, “pass”, “Pass Labs”, “Pass Laboratories”, Supersymmetery”,
“Aleph”, and “Zen” and are all registered trademarks of Pass
Laboratories, Inc., and all rights thereto are protected by law.

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XP-10 Owner’s Manual
Please check with the factory-authorized distributor in the country you are
purchasing this product for specific warranty information.
All Pass Laboratories products purchased from an authorized Pass Labora-
tories dealer in North America are covered by a transferable, limited 3-year
warranty. This warrantee includes all parts and labor charges incurred at the
repair facility in addition to return shipping to the domestic customer, exclu-
sive of subsequent damages. Damage due to physical abuse is specifically
not covered under this warranty.
For this warranty to apply the customer is responsible for returning the
product unmodified to the factory within the warranty period. The customer
assumes all responsibility for shipping and insurance to the factory or a fac-
tory specified repair facility. The conditions and stipulations of this Pass
Laboratories warranty only applies to units sold new in North America.
Non-North America customers should consult with their original Pass Labs
dealer or distributor for warrantee repair instruction prior to contacting the
factory or shipping product for repair.
Non-North American product must be returned to the country of origin for
warrantee service. Foreign distributors are only required to offer warranty
service on Pass Laboratories product that they have imported.
Please note: Conditions of warranty service and customer rights for product
purchased outside the United States may vary depending upon the distribu-
tor and local laws. Please check with your local distributor for specific rights
and details.
Any modifications to Pass Laboratories products that have not received
written factory approval nullify all claims and void the warrantee. Should a
modified product be returned to the factory for repair the owner will be re-
quired 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 suspected
as counterfeit 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 inter-
national markets either to authorized Pass Labs dealers or to third parties
located in the United States or Canada.
Warranty Information

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XP-10 Owner’s Manual
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.
For your protection please
read the following:

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XP-10 Owner’s Manual