Owner's Manual

12
Front Panel Operation
On-Off Button
Push once to turn on the A 21+. When the A 21+ is turned on the dim blue glow around the On-Off button will
become brighter and the two blue channel indicators will illuminate. Push the button again to turn off the A 21+.
The front panel On-Off button will be disabled when the Turn On Options switch is set to Audio or 12 V.
Whenever the A 21+ is turned on, the soft blue glow behind its On-Off button changes to red for a few seconds
until its internal circuits have stabilized. Then the red glow is replaced by a brighter blue glow to indicate
normal operation. If the glow remains red after turn on or while the amp is playing, it indicates activation of the
A 21+’s protection circuits and no sound will be heard from the speakers.
The A 21+ protects itself from external conditions such as excessive heat, load impedance that is too low, or a
short-circuited speaker connection or wire. After you correct the fault, the A 21+ will resume operation. If the A
21+ remains in “protection mode” after it has cooled down and you’ve confirmed there are no external faults, it
could indicate an internal problem. Please contact Parasound’s Technical Service Department.
Channel Indicators
When the two blue channel indicators are lit, the A 21+ is operating normally. If one or both of the indicators
does not light, even though the amp is turned on, there is a fault in your system. In the case of a fault first
check that there is no short circuit with your speaker wire or speakers.
Hi Temp Indicator
This indicator is near the right side of the panel recess. It will glow red if any channel overheats. The On-Off
button will also glow red if the A 21+ overheats. If such a condition occurs you must provide for better
ventilation around the amplifier or check speakers for faulty operation that is causing the A 21+ to overheat.