Pass Labs X2.2 Manual Do Utilizador

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X2.2 Owner’s Manual
the total mismatch to about .1%, for a common-mode rejection of  
approximately  -60 dB.
The input system of  the preamplifier 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 use of  a micro-controller allows all of  the preamplifier functions 
to be repeatable and accurately controlled.  The micro-processor 
only controls the functions of  the preamplifier.  At no time does 
any of  the input or output signal come into contact with the digital 
control signals.  The digital circuits are powered by a power supply 
that is completely separate from the analog supply.  Should it ever be 
necessary to update the software that controls the functioning of  the 
preamp only the socketed  micro-processor need be changed.  
The power supply for the X2.2 consists of  a toroidal power 
transformer delivering an unregulated +/- 45 volts which is actively 
regulated before feeding passive filtering and powering the constant 
current sources which bias the gain stages.  Each channel has its own 
regulation.  The power supply noise reaching the circuit is on the 
order of  one microvolt, and the little of  that which gets through the 
circuit is rejected at the output in a balanced system.  The relays and 
control systems are regulated independently, and all digital circuitry is 
isolated from the power supply.
Muting relays, which delay connection during turn-on and shut off  
the output when insufficient power supply is available to maintain 
regulation, guard the output of  the preamplifier.  The preamplifier 
is designed to run constantly, and will exhibit optimum measured 
performance within about 10 hours of  turn-on. 
The X2.2 consists of  a single chassis.