Short Circuit Protection; Rack Mounting - YORKVILLE CR5 Owner's Manual

Limiter
The limiter switch located on the back panel of the amplifier changes the mode of the limiter. When the limiter
switch is in the "peak" position, the limiter acts as a peak limiter with a short decay time. This allows the bass
thumps in music to drive the output of the amplifier into clipping for the duration of the thump, but will not
heavily clip a continuous signal like someone screaming into a microphone. When the limiter switch is in the
"average" position the release time of the limiter is extended and the limiter acts more like a leveler. This
mode is useful for public address applications where the full headroom of the amplifier is utilized and the
quality of the voice is maintained by using the soft clipping feature of the limiter.

Short Circuit Protection

The CR5 is fully protected against all possible passive loudspeaker load conditions. It can operate with a
"dead" short continuously without damage (however, we don't recommend that you short your CR5 "just for
fun"). Shorts create a lot of stress on the output devices. If a short is present on the output of the amplifier
with a signal passing through the amplifier then the protect LED will illuminate and the amplifier will go into
"sleep mode" turning off the audio signal passing through the amplifier. After 8 seconds, the amplifier will
allow the signal to pass through the amplifier and check to see if the short has been removed. If the short is
still present the amplifier will go through the sleep mode cycle again. If the short has been removed, the
amplifier will continue to drive the speaker. The output protection will allow the output of the amplifier to
drive up to 35 degrees of phase shift at 4-ohms or a load impedance of 3-ohms with no phase shift.
Cooling & Thermal Protection
Passive cooling (this means that there isn't any fan in the amplifier) was chosen for this design to provide years
of mantainence free operation. In dusty locations dirt may settle on the heatsinks. If the amplifier is permantly
installed in a location the heatsinks must be cleaned regularly.
When operating the CR5 care should be taken to allow adequate cooling around the heatsink fins along the
sides of the chassis and not to block the ventilation holes in the top and bottom covers of the chassis. The CR5
was designed to run cool under normal operating conditions, but restricting the airflow around or through the
amplifier could cause the amplifier to thermally shutdown.
If the temperature on the heatsinks of the CR5 exceeds the safe operation temperature, then the amplifier
will shutdown illuminating both protection LED's and turn off the audio signal to the speaker output jacks
until the heatsink temperature drops to a safe level.

Rack Mounting

The CR5 was designed to mount into a standard 19 inch rack. Care must be taken to provide adequate ventla-
tion around the amplifier. Here are some tips to ensure that the CR5 will have adequate cooling when mount-
ed into a rack:
• Leave a blank rackspace above and below the amplifier when stacking equipment into the rack.
• If several CR5s are stacked in a rack, in addition to the tip above, provide fan forced cooling from the bot-
tom of the rack up through the amplifier stack.
The rack itself should have adequate ventilation to the outside air. Leave the front and back of the rack as
open as possible. If fans are used, draw the air in through the bottom front of the rack, drive the air up
through the amplifiers, allowing the air to vent out through the top back section of the rack.
Clip / Protection LED's
The clip/protection LEDs on the front panel will blink to visibly indicate any signal excursion beyond the
dynamic headroom of the amplifier. The clip/protection LEDs will remain on when the amplifier goes into its
protection mode. The CR5 will go into protection for one of three reasons:
• The power switch of the amplifier has just been turned on or off.
• The amplifier has a shorted speaker load on the output of the amplifier.
• The temperature on the heatsinks of the CR5 exceeds the safe operation temperature.
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