Power Amplifier - General; Speaker Connections - YORKVILLE AP812 Owner's Manual

User tip: If you have an electronic-crossover or processor/crossover, you can drive
subwoofers and full-range cabinets in a biamped system with the AP812/818. The
hookup goes as follows:
1) With the EQ/AMP ASSIGN button down in the MAIN/MON position, run a patch
cable from the POST EQ MAIN (L) LINE OUTPUT to the input on an electronic
crossover/processor.
2) Now run a second patch cable from the low-frequency or subwoofer output on the
crossover to the AP812/818's AMP 1 INPUT and a third patch cable from the
crossover's high-frequency or full-range output to the AP812/818's AMP 2 INPUT.
3) Now connect two 8 Ohm sub-
woofers or one 4 Ohm subwoofer
to the AMP 1 SPEAKER connector/s
and two 8 Ohm full-range cabinets
to the AMP2 SPEAKER connector/s.
4) The complete system is now func-
tional, not including monitors.
How-ever, if you need to vary the
comparative volume levels of the
subwoofer/s relative to the full-
range cabinets, another setup will be required with an external power amp for
the subwoofers or employing powered subwoofers. In that system, AMP 1 would
be for full-range speakers and AMP 2 would be for monitors. In other words, this
is a standard setup but with the MAIN (L) LINE OUTPUT going to the input of
the processor/crossover and then to an external amp driving the subwoofer/s, or
simply direct to the input of a powered subwoofer (ours have crossovers built in).

POWER AMPLIFIER - GENERAL

The AP812/818 has a built-in 800 watt stereo power amplifier. Each channel has an
input sensitivity of +4dBv (1.4 volts RMS) for full-power output and each can deliver
over 400 watts into a 4 Ohm speaker load. These amplifiers incorporate computer
designed internal heatsinks and a variable-speed fan which automatically provides
quiet operation consistent with cooling requirements. Cool air is drawn into the front
of the mixer, and heated air is expelled along the bottom of the back. Even at maxi-
mum power, this arrangement results in quiet, dependable performance.
PLEASE NOTE: THE AIR VENTS AT THE FRONT AND BOTTOM REAR OF THE
MIXER ARE ESSENTIAL FOR PROPER OPERATION. BLOCKING THE FREE FLOW
OF AIR THROUGH THE MIXER WILL RESULT IN SYSTEM SHUT-DOWN DUE TO
OVERHEATING. REPEATED OVERHEATING MAY EVENTUALLY CAUSE DAMAGE.
PLEASE KEEP THE VENTS FREE OF OBSTRUCTIONS.

SPEAKER CONNECTIONS

Two 1/4-inch jacks and one Speakon ® connector are in parallel with each amp-
channel output stage. This allows the use of speaker cables equipped with either type
of connector. For full-power applications we recommend 14-gauge cables equipped
with the Speakon ® connectors. This will reduce risk of resistance buildup. The
Speakon ® system, developed in recent years by Neutrik in Switzerland, features
block-style contacts capable of handling large amounts of power and the connectors
lock down to prevent accidental kick-outs.
Connect one or two 8 Ohm speakers or one (only) 4 Ohm speaker to each chan-
nel. When connecting the Speakon's ® , push them in firmly and twist in a clockwise
motion. Push the tab and twist counter-clockwise to disconnect.
User tip: To connect two (8 Ohm) speakers to one or both of the AP812's powered
output channels via the Speakon ® connectors, run a single Speakon ® -equipped
cable, e.g. Yorkville model SP2-25SS or SP2-50SS with Speakons ® at both ends (most
higher-powered speaker enclosures now feature Speakons ® as well) from the
AP812/818 to one of the enclosures. Now run a second cable from one cabinet to
the next via their dual, parallel inputs.
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