Audioplex AT-6P Installation Manual

SIX SPEAKER SELECTOR WITH AUTOMATIC
Your AT-6P Speaker Selector is designed to operate with up to 6 pairs of loudspeakers of 4, 8, and 16
Ohm impedance in any combination, and two (2) power amplifiers each of which is dedicated to drive 3
speaker pairs. Speaker pairs 1, 2 & 3 are driven by amplifier A, and pairs 4, 5 & 6 by amplifier B. This
unique arrangement permits much more efficient operation because substantially less resistance needs to be
inserted in series with the speakers to maintain a safe amplifier load of 4 Ohms or higher. Thus there is
less power loss, permitting higher power output with cooler amplifier operation.
While primarily intended for use with 8 and 16 Ohm speakers, a 4 Ohm switch is provided for each set
of 3 speaker pairs to insert a small amount of extra resistance in the protection circuit when used with 4
Ohm units. Proper protection with 8 and 16 Ohm speakers is fully automatic.
The amplifier impedance load protection circuit uses a progressive system, inserting no more resistance
in series with the speakers than is needed to insure that the load never falls below 4 Ohms, regardless of
how many speakers are switched "ON" at one time. There will be no resistance inserted and no power loss
when any one or two speaker pairs are turned "ON" in each bank of 3 (1, 2 & 3, or 4, 5 & 6) unless the "4
Ohm" switch is in.
No more loss is inserted than is necessary to maintain the load appearing on the amplifier at 4 Ohms or
higher, assuring safe operation no matter how many speakers are in operation at any one time.
Each 4 Ohm switch must be used when more than one pair of speakers are in operation at the same time
in it's associated bank of 3 (1, 2 & 3, or 4, 5 & 6), and one of them is 4 Ohms. If using only one 4 Ohm
pair with no other speakers switched "ON", the 4 Ohm switch can be left "OUT" to gain maximum power
output to that speaker pair.
Other AT-6P features include power handling capability of up to 90 Watts RMS continuous (180 Watts
audio) at 8 Ohms in any switching mode, and completely separate circuits for the Left and Right channels,
thus assuring safe operation with all types of amplifiers, including those with "bridging" outputs.
Maximum power input is somewhat less when the 4 Ohm protection is switched "IN".
Connections to amplifiers and speakers are illustrated in the back of these instructions. Remember that
the LEFT and RIGHT circuits are separate, so connections must be made correctly or the system will not
operate properly.
Since 2 amplifiers are used, and each is dedicated to a group of 3 speaker pairs, some advantage can be
gained by considering how the speakers are to be used. Some locations, such as bedrooms, bathrooms etc.,
will most likely require lower listening levels than others. If there are 3 such locations , they could be
assigned to group 1, 2 & 3 (AMP A) or 4, 5 & 6, (AMP B) and connected to a lower power amplifier. It is
also possible to feed different musical material to each group, so background music could be sent to 3
locations, and the prime listening material to the other 3.
Output connections can be made directly between the AT-6P speaker output terminals and the
loudspeakers, or through an in-wall speaker volume control (such as the AUDIOPLEX TECHNOLGY(tm)
35W-2 series) in rooms where local control is required.
Connect each of the two amplifiers to the "A" and "B" terminals as shown. Make sure the + and -, and
L and R channel connections are correct to avoid unsatisfactory operation or dead channels.
TECHNOLOGY
IMPEDANCE MATCHING PROTECTION
INSTALLATION: