pass TM XA100 Owner’s Manual May 18, 2006 Manual XA100 Owner’s 1
Introduction Analog designer Nelson Pass has over the years produced some truly great solid-state amplifiers, each unique in it’s own way. Not surprisingly, the Pass Laboratories ™ XA100 monoblock amplifier is no exception. The XA100’s sleek industrial design is a stunning understatement of artistic form integrated with state of the art function.
The XA100 has a massive toroidal transformer coupled to a high current DC reservoir. Recognizing that the XA100’s ability to resolve microdynamics is best experienced with clean power, the extreme low-level resolution of the XA-series benefits from a specially designed power supply that significantly reduces and rejects power line borne noise. The XA amps open the sonic soundstage to the very limits of the recording format.
Several XA100’s may be easily run in conjunction with other audio products on a single 15-amp circuit. This amplifier is equipped for operation with an earth ground provided by the users AC outlet. Never defeat this ground connection. The signal ground of this amplifier is connected to earth through a power thermistor, which provides a safety ground but provides protection from irritating ground loops.
are charged. 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 to 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 yet. You can go ahead and connect the source and speakers. Make sure you are in standby mode to protect your speakers from transients.
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, make sure the power cord is attached and plugged into mains power; push the front panel button to activate the amplifier. The “Power” LED will come on. You are ready to play music Do everybody a favor and try not to have shorted output cables. It happens accidentally all the time, and the amplifier is designed to survive, but why tempt fate.
More things to know Speaker Interface You may remotely operate the stand-by mode by applying 12 volts DC to the single pair of 5 way connectors on the rear of the amplifier. The positive of the 12 volts DC goes to the red connector, negative to the black. This connection has an actual operating range of about 9 volts to 15 volts. This switching feature will override the front panel button, only when the front panel button is in the standby position. The XA100 is optimized for 8-ohm speaker loads.
Speaker cables should be firmly tightened down at the speaker output terminals, but not with a wrench. Output terminals will not withstand the levels of torque that may be easily applied by wrench. Hand tightening without excessive force is plenty. Cleaning contact surfaces with one of the commercially available electronic contact cleaners should be part of your annual system maintenance.
XA100 Specifications All figures obtained after 1 hour warm-up, with regulated 120 VAC power line. See manual notes about AC power line regulation. Gain Freq. Response Power Output Damping factor Slew rate Output Noise Balanced CMRR DC offset Power Consumption Temperature 26 dB -3 dB at 1.5 Hz, -3 dB at 100 kHz 100 watts max @ 1% THD, 1 kHz, 8 ohms plus, minus approx. 40 volts plus, minus approx.
Warranty Information 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 Laboratories 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, exclusive of subsequent damages.
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.
XA White Paper: Like Peanut Butter and Chocolate © Nelson Pass Sometimes two designs complement each other so well that you are surprised when you learn they weren’t invented together. So it is with the X Supersymmetery™ amplifier and the Aleph single-ended Class A output circuit. The Supersymmetery™ “X” amplifier repeatedly demonstrates the possibilities for very high power, dramatic dynamic contrast, and effortless control by a simple circuit utilizing absolutely minimal feedback.
they vanish at the output, typically by a factor of 10 or so for matched single-ended Class A circuits. Supersymmetry™ extends this concept by using feedback only to make the distortion and noise more identical on each half of a balanced circuit, not to eliminate it as such. This gives as much as a 100:1 reduction in unwanted distortion and noise without requiring the equivalent amount of negative feedback.
The amplifier has only the two stages, an input stage of a balanced pair of input devices, and the output stage, a balanced pair of single-ended Class A power Mosfets. Like the Aleph™, you can trace a path from input to output through only two gain devices. Like the X amps, feedback is used only to set the gain and correct for dissimilarities between the two matched output stages. There are no adjustments. There are no frequency compensation capacitors.