Audioplex QUADTROL, OPTIMATCH Installation Manual

INSTALLATION MANUAL

TECHNOLOGY

QUADTROL w/OPTIMATCH

TM

TM

SPECIFICATIONS:

Attenuator type: Tapped auto transformer. (4)
Switch: 4-Pole, 12 position rotary, make-before-break contacts, low torque specifications

for smooth feel.

Connector: Screw-tight type, non-removable.
Power rating: 72 Watts RMS continuous 35 Hz-20 KHz, 216 Watts audio.
Frequency response: +0, -1 dB worst case (-6 dB tap), +0, -0.2 dB all other taps, 35 Hz-20 KHz.

Measured at full power, 8 Ohm load. Most controls better these specifications.
Transformers: Tri-filar wound for flat response and minimum phase shift, grain-oriented, high

silicon steel laminations.

Attenuation: -34 dB in 12 steps, 8 steps @ -3 dB each, 1 step @ 4 dB, 1 step @ -6 dB, last step

OFF.

Mounting: Fits in a modified plastic double gang box. Will not fit in a metal box!
OPTIMATCH (TM): Will match impedance for almost any situation. Mechanical index (furnished)

permits presetting load impedance multiplication by X2, X4, X8, X16, X32, X64,

etc. Can be changed at any time.

The AUDIOPLEX TECHNOLOGY. QUADTROL(TM) is a 4-channel (or Quad) tapped
autotransformer type volume control for use with multi-channel systems such as surround, multispeaker
stereo, etc. It incorporates the well-known OPTIMATCH(TM) impedance matching system and wide
band tri-filar wound transformers.

The QUADTROL(TM) Will fit in a modified double gang plastic box (back of box needs to be
removed). Will not fit in a metal box! Screw type connectors are provided to ease installation.

A 4-pole, 12 position switch with shorting type contacts is used to provide a wide range of control.
Attenuation steps are 3 dB each except for the last 3, which are 4 dB, 6 dB and OFF respectively for a
total range of 34dB.

The tri-filar wound transformers combined with premium grade high silicon grain-oriented steel
laminations insure the best frequency response on all attenuation taps to be found anywhere! Worst case
response is +0, -1 dB at 20 KHz with an 8 Ohm load, usually encountered at the -6 dB tap which is at
mid-winding. In most cases, response is better than this.

The OPTIMATCH(TM) feature permits adjustment of the control to reflect whatever impedance is
desired from the controlled loudspeaker to the amplifier. This is accomplished by taking advantage of the
fact that the reflected speaker impedance is doubled for each 3 dB step of attenuation. A lock is provided
so that the reflected impedance can be limited to whatever is desired--it can be used to set the maximum
volume limit for the area controlled by the QUADTROL(TM).

The OPTIMATCH(TM) is a different concept in self-impedance matching controls. It can be used
either as a full range volume control, or as an impedance matching unit that can be adjusted to meet the
requirements of your installation. One simple adjustment can be made when the control is connected, and
can be changed to accommodate additions to the installation at any time. ONE SIZE FITS ALL! It is
easily retrofitted to almost any existing system.

HOW IT WORKS:

HOW IT WORKS:

The first 8 attenuation steps of this control are 3 dB each. For each 3 dB of attenuation, the
impedance of the load (speaker) on the control is doubled as reflected to the driving amplifier. Thus if an
8 Ohm speaker is connected to the control output and the control is moved one position CCW from its
maximum output setting, the attenuation will be 3 dB (X2), and the 8 Ohm speaker will appear to the
amplifier as a 16 Ohm load.

If the speaker was 4 Ohm in the example above, it would appear as 8 Ohms to the amplifier. It is
apparent that if the amplifier were limited to a minimum of 4 Ohms load, TWO 4 Ohms speaker/control
pairs could be operated simultaneously if the OPTIMATCH (TM) controls were operated at the -3 dB
position as a maximum setting. With 8 Ohm speakers, 4 pairs could be operated simultaneously, or 8
pairs of 16 Ohm speakers could be used in the same circumstance. The control can be operated safely
through 11 of its full range of 12 positions with a remaining attenuation range of 31 dB.

Operating the control CCW one more position to -6 dB doubles the impedance once again from the
previous position above, so that the speaker impedance is now multiplied by 4 (X4). Thus if the control is
limited to a setting of 2 positions less than the maximum, a 4 Ohm speaker would appear as a 16 Ohm
load, and 8 Ohm one as 32 Ohms, or a 16 Ohm one as 64 Ohms. This would allow simultaneous safe
operation of up to 4 pairs of 4 Ohm, 8 pairs of 8 Ohm, or 16 pairs of 16 Ohm speakers. The control will
still have 10 positions remaining, with a 28 dB attenuation range.

The above progression repeats for each additional switch position CCW. At 3 positions down (-9 dB)
the impedance is doubled again, multiplying the load impedance (Z) by 8 (X8) with a remaining control
range of 25 dB in 9 steps. The next position would be -12 dB, doubling the load impedance again so that
it will be multiplied by 16 (X16), leaving a control range of 22 dB in 8 steps. This progression can be
continued, although the need to do so is highly unlikely.

The above characteristics can be achieved in a foolproof manner by use of the simple adjustable stop
mechanism furnished with the control. If impedance matching is not a consideration and the full range of
the control is desired, the mechanism need not be used. However if matching is a requirement,
adjustment is accomplished easily observing the following instructions.

The mechanical stop provides an additional function, it may be used to set a maximum volume limit in
a room or location were low level sound is desired to protect either the ears or the speakers. If this is
done, be sure to set the stop at a point where the maximum setting is lower than that required for a safe
impedance match.

INSTALLATION:

Wiring the system is done identically to the manner of hooking up standard attenuators. The controls
are installed ONE PER SPEAKER PAIR and in parallel. Wiring may be such that one wire pair from the
amplifier feeds the system with each control connected across like lamp sockets in a 120 volt AC house
wiring system. Another common approach is the "home run", where the wires from each control are
individually brought to the amplifier, or a junction box (such as the MJ-1 Terminator ) and then to the
amplifier. Either method works well, although line losses may be slightly less with the "home run"
system. DO NOT CONNECT CONTROLS IN SERIES! They will not operate properly.

Note that the Left and Right attenuator circuits are completely isolated from each other to prevent
instability when used with certain types of amplifiers which have floating grounds. If the amplifier to be
used has common grounds between channels, a 3 wire system can be used between the amplifier and
control, but it will be necessary to connect a jumper between the control ground returns (L- & R-). If one
ground is open, there will be no output on the ungrounded channel at any attenuator setting.

1. Make connections by stripping wire insulation back about 3/16". Twist any loose strands
tightly.

2. Insert the wires from the amplifier into the INPUT openings of the connector, L+ to L+, L- to L-,
etc. and tighten screws. Check for stray wire strands that might cause a short circuit. Make sure
the metal part of the screw connector engages the bare wire, NOT the insulation!

3. Similarly, connect speaker wires to the control OUTPUT openings and tighten screws.

4. Install the control in its operating location. SUGGESTION: Leave control 3 or 4 positions CCW
from maximum before firing up the system for the first time to avoid "blasting" the speakers, while
still having enough sound to observe operation.

5. SETTING THE IMPEDANCE MATCHING INDEX: Your OPTIMATCH (TM) Quadtrol (TM)
is furnished with the index system pre-set for full range operation. (no impedance multiplying
factor).

If an impedance matching setting is required, determine the impedance multiplying factor required for
the installation following the information below. EXAMPLE: The system calls for 8 pairs of 4 Ohm
speakers. This requires a control setting of X8, which is -9 dB, or 3 positions CCW from the maximum
volume (full clockwise (CW) setting). To accomplish this, the index must be set to limit the maximum
clockwise rotation of the control knob 3 positions back from full position.

Remove the knob by pulling it straight away from the panel, and loosen the nut slightly. Rotate the
index finger so that the finger is at about 120 degrees counterclockwise from its original position. Turn
the control shaft fully CCW to the OFF position. Install the knob so that it is fully on the shaft. (HINT:
The knob must be removed and re-installed, a little wax or soap on the shaft will make the job easier.)
Rotate the knob clockwise slowly, counting the switch index positions as you go. Note that the fully
CCW OFF position must count as position #1!

There are 12 positions on the switch. Count up the number that is 12 minus the number of steps down
you wish to set the control. Example: You wish to set the control to X8, which is -9 dB or 3 positions
down from the maximum setting (the pre-set X4 is -6 dB, 2 positions down). In this case you would
count 9 positions (12-3) and stop. (You will probably notice some increased resistance when the stop
inside the knob picks up the index finger.) Holding the control-plate assembly steady, remove the knob
and tighten the index nut. Replace the knob. Check the rotation to make sure you have obtained the
proper number of steps. MAKE SURE THAT THE SWITCH IS IN AN INDEXED POSITION AT THE
MAXIMUM SETTING! an in-between position can cause an excessive load on the system amplifier. If
necessary, repeat the above procedure to achieve satisfactory operation.

OPTIMATCH (TM) INDEX SETTING INFORMATION:
X2- 1 Position CCW from max.- use 2-4 Ohm or 4-8 Ohm speakers simultaneously.
X4- 2 Positions CCW from max.-use 4-4 Ohm or 8-8 Ohm speakers.
X8- 3 Positions CCW from max.-use 8-4 Ohm or 16-8 Ohm speakers.
X16-4 positions CCW from max.-use 16-4 Ohm or 32-8 Ohm speakers.

WARRANTY

Your AUDIOPLEX TECHNOLOGY Quadtrol(TM) is covered by a Lifetime warranty against any defects in
workmanship and materials. Any defects will be remedied without charge for labor or parts.

Damage incurred by shipping or accident is not considered to be a defect, and not covered by this warranty.

AUDIOPLEX TECHNOLOGY, is not responsible for defective operation caused by abuse or by modification or
service by any unauthorized person or agency.

The unit must be properly installed and operated according to instructions for the warranty to apply. Any
necessary servicing must be done by AUDIOPLEX TECHNOLOGY. The unit must be returned expenses prepaid,
with written authorization from the company. The product must be shipped with the proof of purchase and in the
original carton and packing material to avoid damage.

This warranty gives you specific legal rights. You may have other rights which vary from state to state.

WIRING DIAGRAM

AMPLIFIER 1AMPLIFIER 2

OUTPUT

INPUT

- R +- R + - L +- L +

OUTPUT

- +

- 4 +

- 4 +

- +

- 1 +

- 2 +

- 3 +

- 1 +

- 2 +

- 3 +

- +- +

2000 - 6/26/00

#3#4

#1#2

AUDIOPLEX TECHNOLOGY

1-800-257-2077 IN N.H. 1-603-544-8601

404 GWH P.O. BOX 440

MELVIN VILLAGE, N.H. 03850

FAX: [phone]

E-mail: [e-mail]