Pass Labs XA200 - Manual (Page 2)

2 XA200 Owner’s Manual
Analog designer Nelson Pass has over the years produced some truly
great solid-state amplifiers, each unique in it’s own way. Not surpris-
ingly, the Pass Laboratories ™ XA200 monoblock amplifier is no ex-
ception. The XA200’s sleek industrial design is a stunning understate-
ment of artistic form integrated with state of the art function.
Since the introduction in 1997, the X amplifier series using the pat-
ented Supersymmetry™ circuit topology have been the mainstay of
amplifier offerings from Pass Laboratories™. These amplifiers are
heavily biased Class A/B designs with only two gain stages and an ab-
solutely minimal component count in the signal path. In spite of this
simplicity and thanks to the unique characteristic of the X topology,
these amplifiers achieve very high power with outstanding subjective
and objective performance.
With the introduction of the XA200 Pass Laboratories™ significantly
raises the performance standard of excellence by introducing an en-
tirely new series of power amplifiers. The new “XA” series of ampli-
fiers feature a refined and elegantly simple, very highly biased, pure
Class A mode of operation. This is a new and unique circuit topology
that we descriptively characterize as being Single-ended Class A. This
new topology combines the very best characteristics of Pass Labora-
tories™ “X” series amplifiers and the highly rated “Pass Laboratories
Aleph™”. The XA series is the marriage of a highly refined Aleph™
output stage with the patented Supersymmetry™ “X” front end.
The emphasis of the XA series is to accentuate performance over
power. The XA series has the characteristic warm midrange and sweet
top end of the Aleph™ product conjoined with the extreme dynamic
range and definitive bass control of the X series amplifiers.
The XA 200 is packaged in an artistically refined variant of the mas-
sive chassis previously reserved for the 1000 watt X-1000.5 monob-
lock amplifier, but running more than twice the Class A bias current
of our other amplifiers.
The Pass Labratories™ XA200 will deliver 200 watts rms into 8 ohms
of impedance. This is the amplifiers class A limit, driving the XA200
harder or reducing the impedance of the load will not convey any
additional power. Driving into a short will not convey any additional
power. These are not design oversights or flaws in the XA200, but
rather a condition of the very highly biased Class A operation. How-
ever; as an interesting point of reference, 200 watts driving a 87dB/
1W/1m speaker will deliver a 112 dB (very loud) average acoustic sig-
nal in a 100 cubic meter room, peaks will be somewhat higher.
Introduction