TM
pass
X260.5 Owner’s Manual
Sept 23, 2009
1
Century and the elegance to retrieve the micro dynamics offered by
the most sensitive loudspeakers. The simple but powerful circuitry
moves easily from total silence to explosive transient and back to
silence without a trace and without information loss. Very unlike
conventional high power amplifiers, they provide this level of power
with a subtlety befitting some of the better tube amplifiers. This per-
formance is consistence across the audio spectrum and the amplifiers
are unconditionally stable into all speaker loads.
So relax and enjoy your amplifier. Call us if you ever have a problem
or question. You are welcome to ask questions or offer comments.
Thank you for buying our product.
3
X260.5 Owners Manual
Setup
You can position this amplifier most anywhere you wish, but it re-
quires adequate ventilation. We do not recommend placing it in
enclosed cabinets or small closets without means for air to circulate
freely. Stacking these power amplifiers directly upon each other is not
recommended for the same reason. This amplifier typically idles at
slightly more than 250 watts, most of which dissipates as heat across
the heatsinks. As a point of reference, these heatsinks should never
become too hot to touch for several seconds.
Let’s talk about AC power requirements. This amplifier draws about
2 amps (continuous rms) at 120 volts out of the wall during normal
operation, and this power draw reflects mostly the idle current that
we run through the output stage. If you are driving a low impedance
load, you will draw more power than this, but this will not be typical.
The amplifier’s voltage and current rating are indicated on the rear
panel. It will be 240 volts, 220 volts, 120 volts or 100 volts, all with
an appropriate rear mounted replaceable type 3AG slow blow fuse.
For units rated at either 220 or 240 volts the fuse will be a 2-1/2 amp
type 3AG, 250V slow blow and for units rated at either 100 or 120
volts the fuse will be a 5 amp type 3AG, slow blow. Do not substitute
other types, voltage, amperage or time constant fuses for the specified
replacement.
The frequency rating of the AC line source in all instances will be 50 to
60 Hz. Please verify that the amplifiers indicated voltage requirements
are consistent with the line voltage supplied at your location.
The Pass Laboratories™ X150.5 is provided with a conventional IEC
detachable AC line cord, which is rated at 15 amps. The safety ground
is attached to the chassis in the conventional approved manner. The
AC power input to the amplifier runs through a RF filter, which re-
moves high frequency noise coming into and going out of the ampli-
fier power supply.
Under no circumstances should you defeat the ground connection of
the power cord. For your safety, the chassis of the amplifier should be
earth grounded. Signal ground is isolated from chassis, safety ground,
to reduce the incidence of ground loop noise. The presence of a
safety ground will not degrade the audio signal chain.
You may substitute an aftermarket detachable IEC 320 style power
cord of your choosing; provided it is rated for at least 15 amps and it
meets all legal requirements and has been approved by the local testing
authority for such things.
4
X260.5 Owners Manual
Looking at the rear panel you will see the IEC 320 AC power cord
receptacle, a mains power switch, two pairs of output connectors, a
pair of binding post connectors for remote turn-on, one RCA input
connector and one XLR balanced input connector.
Make sure that the mains power switch is off (down). Plug the AC
cord into the back of the amplifier, and then into the wall. Then turn
the breaker switch on (up). The lights in your house may blink when
the power supply charges the capacitors; this is normal. This mains
power switch is not to be used as a safety disconnect during servicing
and is not a substitute for unplugging the power cord.
On the front panel, the “Standby” LED indicator should be glowing
blue, indicating that the power is on. The “Power” LED should not
be on. If the “Power” LED is on, don’t get excited, just use the front
panel stand-by button to go into stand-by mode, with the “Standby”
LED on and the “Power “ LED off.
OK, so the amplifier is sitting there in stand-by mode with just the
single blue LED lit. No speaker connected, as yet. You can go ahead
and connect the source and speakers. Some speaker cables are very
difficult to work with due to physical size and construction, make sure
the speaker connections do not short together. It is recommended
that you connect the speaker ends of these cables first.
Some powered subwoofers require an audio signal ground reference
and their makers may suggest that a black speaker terminal is where
this voltage reference might be found. On complementary designs,
which would be typical of all power amps produced by Pass Laborato-
ries™, this is an incorrect and unsafe assumption. On all Pass Labo-
ratories™ power amplifiers a reference of 0 volts will be found only at
pin 1 of the XLR input or at the shell of the RCA input.
Reference connections for these devices require special consideration
when used with our product. If you have such a device, and wish to
use it with our product, please contact our Foresthill, California fac-
tory for specific instructions.... you have been warned.
XLR input connector showing
proper placement of jumper pin
for use with single-ended (RCA)
input.
Note: On X260.5 XLRs are
upside down.
5
X260.5 Owners Manual
The amplifier can be driven single-end or balanced, if driving the am-
plifier single-ended, leave the supplied jumper in place (between pins
1 & 3 on the XLR). Your amplifier will operate without the jumper in
place, but performance will be significantly diminished.
Now that the source component is connected, make sure there is no
signal coming from it, probably by turning the volume all the way
down. With the speakers connected, push the front panel button to
activate the amplifier. The “Power” LED will come on.
Do everybody a favor and try not to have shorted output cables. It
happens accidentally all the time, and the amplifier is designed to sur-
vive, mostly.
You are ready to play music
Of course it’s always possible that something could go wrong. If so,
don’t get excited, just relax. It’s really aggravating when something like
this doesn’t work, we understand, but it will get fixed. We go to a lot
of trouble to make products reliable, and the failure rate of our ampli-
fiers is very low. This is small comfort to the few, but take it easy and
give us a call if you have problems.
People are often interested in how long it takes for these amplifiers
to break in. Perhaps a more salient question is how long does it take
them to reach their sonic best after turn on. It takes about an hour for
them to fully warm up, and this is where we adjust them first. Then
we adjust them again and again over a couple of days, keeping the bias
and offset in the sweet spot. Our environment is about 23 degrees
Centigrade and the heat sinks will rise approximately 25 degrees C.
above that, for an average on heat sink temperature of 48 degrees C.
Sonically they are at their best when the heatsinks are approximately
50 degrees C.
In your setup the temperature may vary a bit due to line voltage varia-
tions and ventilation, but this is not a big deal. You should be able to
put your hands on the heat sinks without discomfort for 10 seconds
or so. It is normal for the heasink temperature to vary side-to-side and
front to back.
The amplifier has a thermal cutout that will disconnect AC power if
the temperature exceeds 75 degrees Centigrade. This should never
occur in real life.
More things to know
You can remotely operate the stand-by mode by applying 12 volts DC
to the single pair of binding post connectors on the rear of the ampli-
6
X260.5 Owners Manual
fier. The positive of the 12 volts DC goes to the red connector. This
connection has an actual operating range of about 9 volts to 15 volts
at a current draw of approximately 5.0mA. This switching will over-
ride the front panel button, so if you want the front panel button to
operate, leave the rear connection open.
So much for the most essential information.
Speaker Interface
The Pass Laboratories™ X260.5 is optimized for loads nominally rated
at 4 ohms and above. You can run the amplifiers into a lower nominal
impedance without difficulty, and we are not aware of a speaker on the
market that presents unusual difficulty with these amplifiers.
The X.5 series amplifiers do not care particularly about the reactivity of
the load. Reactive loads typically will have slightly less distortion at a
given voltage/current level than resistive loads, but will make the ampli-
fier run a little hotter. The X.5 circuit was designed to be quite happy
driving electrostatic and other difficult speakers.
When driving transformer-coupled loads directly, as in some electrostat-
ic and ribbon designs, some attention must be paid to the DC character
of the situation. If the transformer primary is being driven raw with no
protection from DC and your source has DC voltage, or in cases where
the small offset of the power amplifier is still too much, you may cre-
ate distortion in the transformer and get less than optimal performance
from it. Generally this is not the case with transformer-coupled loud-
speakers, but it does occasionally surface. In these cases, take special
care that the source does not contain a differential DC component, and
confirm the differential DC offset of the pre-amplifier is sufficiently
low. This differential voltage is easily adjusted by a qualified technician
armed with the appropriate service documents.
Interconnects and Speaker
Cables
We have a general recommendation about interconnects, which is that
they should cost less than the amplifier, and be flexible enough to work
with. We have tried a lot of products and most of them work well, but
as a practical matter we cannot make blanket recommendations.
The amplifier is not sensitive to source interconnects or ground loops.
It is also not sensitive to radio frequency pickup, which allows some flex-
ibility in choosing source interconnects without shields, though shields
are always in good taste.
We prefer speaker cables that are thick and short. Silver and copper are
the preferred metals. If you find any cable made of gold, please gift us
a couple hundred meters.
7
X260.5 Owners Manual
Fortunately the amplifier is not sensitive to the capacitive/inductive
character of some of the specialty speaker cables, so feel free to experi-
ment.
We have found that about 90 per cent of bad sounding cables are in
reality bad sounding connections, and we recommend that special at-
tention be paid to cleanliness of contact surfaces and proper fit.
Speaker cables should be firmly tightened down at the speaker output
terminals, but do not use a wrench. These connectors will not with-
stand unrealistic foot-lbs of torque. Hand tightening without exces-
sive force is plenty.
Hardware Facts
So how long will this hardware last? It is our experience that, barring
abuse or the odd failure of a component, the first things to go will be
the power supply capacitors, and from experience, they will last 15 to
20 years before needing replacement. Fortunately these components
die gracefully; typically with years of warning and are easily replaced.
After that, the longevity will depend on the number of operating ther-
mal cycles, but we can attest to having had amplifiers operating in the
field in excess of 20 years with no particular mortality except capaci-
tors. We don’t have good information beyond that. More to the point,
we would suggest that you not worry about it. This is a conservatively
built industrial design, not a tweaky tube circuit run on the brink of
failure. If it breaks, we will simply get it fixed, so sleep well.
8
X260.5 Owners Manual
For more information please contact:
Pass Laboratories Inc.
P.O. Box 219,
24449 Foresthill Rd.,
Foresthill, CA 95631
Tel: 530.367.3690
Fax: 530.369.2193
www.passlabs.com
© 2009, Pass Laboratories Inc.
“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.
9
X260.5 Owners Manual
Please check with the factory-authorized distributor in the country you are
purchasing this product for specific warranty information.
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.
10
X260.5 Owners Manual
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.
For Units With Externally Accessible Fuse Receptacle: Unplug
the device from all sources of power before changing or inspecting any
fuse. Replace fuse with one of same physical size, type and rating as that
specified by the manufacturer for that product.
11
X260.5 Owners Manual
|