Mono/Stereo/Bridge Switch; Subsonic Filter Switch; Limiter Switch; Protect Led - YORKVILLE AudioPro AP1200 Owner's Manual

AP1200 OWNER MANUAL / GUIDE D'OPERATION
MONO/STEREO/BRIDGE
SWITCH

SUBSONIC FILTER SWITCH:

LIMITER SWITCH:

PROTECT LED:

SHORT CIRCUIT
PROTECTION:

DC PROTECTION:

Yorkville Sound LTD. 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 carefully before you choose to
run your AP1200 in bridged mode!
The AP1200 features a specially designed subsonic filter which effectively blocks potentially destructive energy
in the band below 30-Hz while enhancing the band between 35 and 70 Hz. Engaging this filter immediately
produces the perception of a better "bottom end", while excessive and possibly damaging excursions of the
speaker cone are restrained. The filter provides an 18 dB/Oct skirt below 40 Hz and a 3.6 dB boost at 50 Hz.
It is implemented with a five 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 AP1200 is flat down to 20 Hz, and rolls off at 18 dB/Oct below that.
With the internal limiters activated, the AP1200's gain is continuously 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 "OUT" position completely disables both limiters.
In the event of a shorted load or a load which is of too low an impedance for the amplifier to handle, (less than
2 ohms), the PROTECT LED will flash alternately on and off at about one second intervals. The sound may
come on and off at the same rate. In this case, the fault is in the speakers or the speaker cables and should be
located and remedied. No reset of the AP1200 is required to restore proper operation.
The AP1200 is fully protected against all possible passive load conditions. It can operate with a "dead" short
continuously without damage. (However, we don't recommend that you short your AP1200 "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 60 Amperes and phase angles
of more than 45 degrees, yet is capable of protecting the output stage from damage due to accidental short circuits
and improper loads.
In the unlikely event of the AP1200's outputs "going DC", a thyristor circuit will short the output terminals and
divert all potentially harmful currents away from your speakers.
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