Pass Labs XA200 - Manual (Page 6)

6 XA200 Owner’s Manual
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.
Do everybody a favor and try not to have shorted output cables. It
happens accidentally all the time, and the amplifier is designed to sur-
vive, but why tempt fate. If you accidentally cause the breaker to trip,
it can be reset by first cycling the breaker handle to the off position
(down) and then on (up). The fault, which caused the “trip”, will need
to be corrected prior to resetting this breaker.
Of course it’s always possible that something may go wrong. If so,
don’t get excited. It’s really aggravating when a product doesn’t work,
we understand, but it will get fixed. We go to a lot of trouble to make
products reliable, and the failure rate of our amplifiers is very low.
This is small comfort to the few, but take it easy and give us a call if
you have problems.
People are interested in how long it takes for these amplifiers to break
in. Depending on the resolution of the rest of your audio chain, you
may or may not notice any break in of the XA200 beyond the first 50
hours of operation. You will likely notice the difference in sonic char-
acter between cold and normal operating temperature, so we recom-
mend letting these amplifiers warm up before any serious listening.
It takes about an hour for them to warm up, and this is where we ad-
just them first. Then we adjust them again and again over a couple of
days, keeping the bias and offset in the sweet spot. Our environment
is about 23 degrees Centigrade, room temperature, and the heat sinks
will rise to about 25 degrees C. above that, for a heat sink temperature
of about 48 degrees C. This is where they operate best.
In your setup the heatsink temperature may vary a bit due to line volt-
age and ventilation, but it is not a big deal. You should be able to put
your hands on the heat sinks without discomfort for 10 seconds or
so.
The amplifier has a thermal cutout that will disconnect AC power if
the temperature exceeds 75 degrees Centigrade. This thermal cutout
should never occur in real life.
You are ready to play music