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MODES
The AAPP66002200can be configured for Bridge, dual-MONO or
STEREO operation via the rear panel MODE switch. The following is a
description of each mode:
MONO MODE
• Channel A& Binputs are paralleled.
• Each gain control adjusts the signal level for its respective
channel,
• Output signals are of equal phase.
• Two loads are driven.
• Loads are connected between the BLACK and RED post on
each channel.
STEREO MODE
• Two independent amplifiers, Amp Aand Amp B.
• Two loads are driven.
• Loads are connected between the BLACK and RED posts on
each channel.
BRIDGE MODE
• Channel A&Binputs are paralleled. GAIN B has no effect.
• Output signals are equal in amplitude but opposite in phase.
• One load is driven.
• The load is connected between the two RED binding posts.
The BLACK posts are not used.
SUBSONIC FILTER SWITCH
The AAPP66002200features a specially designed subsonic filter that
effectively blocks potentially destructive energy in the band below 40
Hz. The filter provides a 12 dB/octave. skirt below 40 Hz. It is imple-
mented with a two-pole network designed to minimize phase shift
down to 40 Hz. We recommend using this filter in conjunction with
some subwoofers and with all high power full range cabinets. With
the filter disabled, the AAPP66002200is flat down to 20 Hz, and rolls off at
12dB/Oct below that.
LIMITER SWITCH
With the internal limiters activated, the AAPP66002200’s gain is continu-
ously adjusted to fit the signal within the available dynamic range.
Occasional clipping is permitted. The limiters will not only help to
protect your system’s horns and tweeters, but will automatically make
the best use of the available dynamic headroom. With the limiters
activated, all you need to do is turn up the signal level until you start
to see some clipping. The limiters will make sure that you are getting
the maximum clean power output at all times. Setting the switch to
the IN position completely disables both limiters.
PROTECT LED
In the event of a shorted load or a load which is of too low an
impedance for the amplifier to handle the PROTECT LED will flash
alternately on and off at about 3 second intervals. The sound may
come on and off at ½ second intervals. In this case, the fault is in the
speakers or the speaker cables and should be located and remedied.
No reset of the AAPP66002200is required to restore proper operation. The
PROTECT LED will stay on if the amplifier has overheated. Check the
speaker load impedance and any restrictions to air flow at the air
intake or exhaust vents of the amplifier.
SHORT CIRCUIT PROTECTION
The AAPP66002200is fully protected against all possible passive load
conditions. It can operate into a dead short continuously without
damage. (However, we don’t recommend that you short your
AAPP66002200“just for fun.” Shorts do create a lot of stress on the output
devices). The output stage uses a unique triple slope VI-limiting
scheme which is sophisticated enough to remain inert during transient
currents in excess of 150 Amperes and phase angles of more than 45
degrees. It is capable of protecting the output stage from damage due
to accidental short circuits and improper loads.
DC PROTECTION
In the unlikely event of the AAPP66002200’s outputs going DC, a thyris-
tor circuit will short the output terminals and divert all potentially
harmful currents away from your speakers.
THERMAL PROTECTION
In the unlikely event that the AAPP66002200overheats, the signal will be
sporadically cut off and the PROTECT LED will stay on. The AAPP66002200
is designed and tested to operate under “worst case” conditions with-
out shutting down, so if you experience a thermal shut down you
should check for blocked air flow.
COOLING
The fan draws air in from the front and expels hot air through the
rear vents. This is compatible with most installations. Since hot air
rises, the heated air forcibly expelled from the back tends to rise away
from the equipment rack. This draws cool air from the floor upwards
into the front of the rack. In some cases where the rear of the rack is
obstructed, it may be necessary to install rack fans to aid cooling. If
there are no obstructions, no secondary cooling is required.
CLIP LEDS
The CLIP LEDS on the front panel will visibly indicate any signal
excursion beyond the dynamic headroom of the amplifier.
RELIABILITY
The AAPP66002200is designed and manufactured by Yorkville Sound.
Each unit undergoes a thorough, temperature cycled burn-in period,
and each circuit is tested by both manual and sophisticated computer
controlled equipment which is capable of identifying any deviation
from the design center parameters. The design of the AAPP66002200is con-
servative with respect to the power handling capabilities of the output
devices. The topology guarantees that thermal stress not secondary
breakdown will set the limits of operation, while the computer opti-
mized heat dissipation system insures that excessive thermal stress will
not occur. Yorkville’s reputation as a manufacturer of reliable equip-
ment will be further enhanced by the AAPP66002200.
The AAPP66002200is not only suitable for use in both heavy duty touring
sound reinforcement systems but also when high headroom and low
distortion are needed to fully reproduce the dynamic range and clarity
of today’s CD recordings. It is built to survive grueling road conditions
and constant 2-Ohm operation. Its reliability in a fixed installation
running 4 or 8-ohm studio monitors is without parallel.
FAN FILTER MAINTENANCE
The AAPP66002200is factory equipped with fan filters mounted on the
air-intake grills located on the amplifier’s front panel. Regular cleaning
of this filter will increase the amplifier’s long term reliability. The fil-
ters should be removed and washed at the first sign of visible clog-
ging. This will typically occur every four to six weeks depending on
use and environment. Replacement filters are inexpensive and can be
ordered through Yorkville dealers. The foam filters should be removed
if a regular inspection schedule is not going to be followed. The
amplifier can operate without the filters in place, but the amplifier
CAUTION: The AAPP66002200can deliver over 2000 Watts of power into a speaker load.
Yorkville
’s own high power speaker systems have circuit-breaker
protection built in. Although these speakers will protect themselves, they are unlikely to be damaged by a AAPP66002200. However, many other speaker manu-
facturers make “high power cabinets” with no protection features at all.
Yorkville
Sound is not responsible for any damage which may result as a consequence of exceeding such a speaker’s power handling capability.
Yorkville
’s two year unconditional warranty does not cover any consequential damages to non-
Yorkville
equipment. Please consider these facts careful-
ly before you choose to run your AAPP66002200!