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with the resistive impedances found in the circuit, and the simplicity of the circuit allows for
what is largely a single pole rolloff characteristic.
The slew rate of the amplifier is about 40 Volts/uS under load , which is about 10 times faster
than the fastest signal you will ever see, and about 100 times faster than what you will be
listening to. In and of itself, the slew rate is an unimportant factor when evaluating tube and
simple Mosfet designs. It becomes more important with complex circuit topologies where
there is heavy dependence on feedback correction, but even then its importance has been
overstated.
On the other end of the spectrum, the amplifier has full DC response, and is perfectly usable
as a DC power supply. There are no capacitors in the gain path of the circuit. After warm-up,
the DC offset in the amplifier is about .05 volts. While warming up, the amplifier will have
higher DC offset, but not so much as to present a performance problem.
It is important to note that full DC response brings with it the potential that DC can be fed to
the loudspeaker if the source has a DC component to it. Exercise caution in this regard to
prevent damage to the loudspeaker. The warranty coverage for this amplifier does not include
damage to loudspeakers. If there is any question that DC might be present at the output of
the amplifier, an inexpensive voltmeter will prove a wise investment. You can check for DC
offset with the source connected and on and the amplifier on, but with the loudspeaker
disconnected. If there is any question, contact your dealer or the factory.
For the lowest possible operating noise in any environment, the amplifier is equipped with
balanced inputs featuring a common mode noise rejection of greater than 60 dB. Balanced
operation is accomplished through a passive network tied directly into the input stage of the
amplifier, not with additional active input circuitry as in other products. This assures that the
noise benefits of balanced operation are not accompanied by the degradation of more
semiconductors in the gain path.
The input of the amplifier is flexible and can also be operated with unbalanced sources. The
input system 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 amplifier is powered by a toroidal transformer which charges .125 Farad capacitance to
150 Joules. This unregulated supply feeds the output transistors only with a full power ripple
of about .25 volt.
The chassis of the Aleph 0 is made entirely of machined aluminum; no sheet metal is
employed. We mill the chassis components ourselves from aluminum stock on four computer
controlled vertical milling machines. We also do the chassis engraving on the milling
machines, which we built ourselves. The pieces are grained and anodized at the finest plating
house on the West Coast.
The Aleph 0 is warranted by Pass Laboratories to meet performance specifications for 3 years
from date of manufacture. During that time, Pass Laboratories will provide free labor and
parts at the manufacturing site. The warranty does not include damage due to misuse, abuse,
or modification to the amplifier and also does not include consequential damage.
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