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Setup

The amplifier has three sets of connections and one switch:

The first connection and switch is the AC line power system.  The amplifier's voltage and
current rating are indicated on the bottom.  It will be either 240 volts, 120 volts, or 100 volts.
100 and 120 volt units are equipped with a 15 amp 3AG type fuse.  240 volt units have a 10
amp 3AG fuse.  The frequency rating of the AC line source is 50 to 60 Hz.

Your amplifier is provided with a standard AC power cord which fits into the line receptacle
located just below the power switch.  The amplifier is equipped for operation with an earth
ground provided by the AC outlet.  Do not defeat this ground.  The chassis of the amplifier is
connected directly to this earth ground, and the audio circuit ground is connected to the
chassis and earth through a power thermistor, which gives a ground connection but helps
avoid ground loops.

While the amplifier is equipped with an AC inrush suppresser, the turn-on AC draw will peak
(half cycle) at roughly 50 amps.

The second connection is at the input.  If your signal source is balanced, you may use the
XLR input connector.  On this connector, pin 1 is grounded, pin 2 is the positive signal input,
and pin 3 is the negative signal input.  The amplifier is shipped with a shorting plug between
pins 1 and 3, which is used for unbalanced operation.  If you will be using the RCA
unbalanced input, leave this plug in.

If you will be using the balanced input, remove this plug, but save it.  Operating the amplifier
in unbalanced mode without this plug will not cause damage, but will not give the full voltage
gain of the amplifier.

If your signal source is unbalanced, input will occur through the RCA input connector, which is
in parallel with the XLR connections 1 and 2.

The unbalanced input impedance of the amplifier is a nominal 10 Kohm.  In balanced mode,
the input impedance is higher, with a differential impedance of 25 Kohm.

The third connection is the amplifier output connection.  Two sets of 5-way connectors are
provided in parallel for use in bi-wiring your loudspeakers if desired.  The RED connector is
hot (+) and the black is cold (-).  Connect the 5-way output connectors to loudspeaker plus
and minus, using the cable of your choice.

Do not drive the amplifier into a direct short.  If distortion or fuse blowing accompany an
attempt to operate the amplifier, please disconnect the loudspeaker first and check for a
shorted circuit.  As the amplifier does not use a current limiting protection circuit, quite a large
amount of power can flow from the amplifier.  The design has been tested to survive external
short circuits, but the possibility exists for failure under these conditions.  Such failure is
covered by your warranty.

Содержание Aleph 1

Страница 1: ...Pass Laboratories Aleph 1 Owner s Manual ...

Страница 2: ...ps and input stages I feel that in specialized and demanding applications the energy penalty is worth the purity of performance obtainable from single ended Class A operation This purity delivers the most musicality and listening satisfaction per watt of any operating mode The Aleph series of power amplifiers has earned top honors around the world since their introduction in 1992 I have been extre...

Страница 3: ... with a shorting plug between pins 1 and 3 which is used for unbalanced operation If you will be using the RCA unbalanced input leave this plug in If you will be using the balanced input remove this plug but save it Operating the amplifier in unbalanced mode without this plug will not cause damage but will not give the full voltage gain of the amplifier If your signal source is unbalanced input wi...

Страница 4: ...itors will get old Depending on usage you will begin to have semiconductor and other failures between 10 and 50 years after date of manufacture Later the sun will cool to a white dwarf and after that the universe will experience heat death Product Philosophy and Design Theory When I started designing amplifiers 25 years ago solid state amplifiers had just achieved a firm grasp on the market Power ...

Страница 5: ...n achieved The history of what has been done to the music is important and must be considered a part of the result Everything that has been done to the signal is embedded in it however subtly Experience correlating what sounds good to knowledge of component design yields some general guidelines as to what will sound good and what will not 1 Simplicity and a minimum number of components is a key el...

Страница 6: ...mportant 4 Given the assumption that every process that we perform on the signal will be heard the finest amplifiers must employ those processes which are most natural There is one element in the chain which we cannot alter or improve upon and that is the air Air defines sound and serves as a natural benchmark Virtually all the amplifiers on the market are based on a push pull symmetry model The p...

Страница 7: ...iers and D A and A D converters They are not monotonic the distortion increases as the level decreases The usual electrical picture of an audio signal is as an AC waveform without a DC component Audio is represented as alternating voltage and current where positive voltage and current alternates with negative in a reciprocal and symmetric fashion This fiction is convenient because it lends itself ...

Страница 8: ...Class A designs has been at issue in the last few years with pure Class A loosely defined as an idling heat dissipation of more than twice the maximum amplifier output For a 100 watt amplifier this would be 200 watts out of the wall at idle Designs that vary the bias against the musical signal will generally have bias currents at or below the signal level This is certainly an improvement from the ...

Страница 9: ...rge gapped core transformers to avoid core saturation from the high DC current but they suffer the characteristic of such a loosely coupled transformer as well The promise of the transconductance characteristic in power amplifiers in providing the most realistic amplified representation of music is best fulfilled in Mosfet single ended Class A circuitry where it can be used very simply and biased ...

Страница 10: ... 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 For the lowest possible operating noise in any environment the amplifier is equipped with balanced inputs fea...

Страница 11: ...oad impedances do not make much difference to the character of the amplifier The amplifier is indifferent to the reactance of the load As a single ended Class A device the worst dissipation case is idle and current flowing into a reactive load does not particularly alter the dissipation Current flowing into a resistive portion of a load will generally make the amplifier run cooler A reactive load ...

Страница 12: ... peak Output Impedance 001 ohm 1 KHz 8V 8 ohm Balanced Input 25 Kohm nominal differential XLR 10 Kohm single ended RCA Common mode rejection 60 dB 1 KHz 1V input common ground Output Noise 600 microvolt DC offset 50 mV after warm up Power Consumption 500 watts Operating Temperature 50 degrees C Warm up time 1 hour minimum Dimensions 16 6 W x 16 5 D x 10 5 H Shipping Weight 122 lbs PASS PASS Pass L...

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