Wheelock MX-8 Mixer Specifications

273 Branchport Avenue
Long Branch, N.J. 07740
(908) 222-6880
INSTALLATION INSTRUCTIONS
MODEL PA-250 AND PA-500
BOOSTER AMPLIFIER
GENERAL:
The Series PA-250 and PA-500 Watt Booster Amplifiers are designed to be driven from a line-level preamplifier source, (i.e. Series MX-8 Mixer or the
line output of any Wheelock paging amplifier). The PA-250 and 500 offers a choice of two different inputs, one low impedance balanced 600 Ohm input
and one high impedance unbalanced LINE IN input. Use of the LINE IN will automatically disconnect the balanced input. The input is buffered and
available at the BOOSTER OUT.
The amplifier features a VOLUME control and an OUTPUT PEAK indicator for the amplifier on the front panel. On the rear panel there is a power
ON/OFF switch with a switched auxiliary AC receptacle.
All inputs and outputs are connected at the rear panel. Screw terminals are used for the 600 Ohm input (see Figure 2). Phono jacks are used as input
and output for LINE IN and BOOSTER OUT (see Figure 2). The audio power output is connected via screw terminals (see Figure 3).
The amplifier operates from 115VAC, 60Hz and has a power consumption of 350 Watts and 700 Watts respectively. There is no external fuse or
circuit breaker. IN THE EVENT THE AMPLIFIER DOES NOT POWER UP, HAVE THE TROUBLE INVESTIGATED BY AN AUTHORIZED SERVICE
TECHNICIAN OR RETURN UNIT TO FACTORY.
NOTE: READ THESE INSTRUCTIONS CAREFULLY. FAILURE TO COMPLY WITH ANY OF THE FOLLOWING INSTRUCTIONS, CAUTIONS AND
WARNINGS COULD RESULT IN RISK OF ELECTRICAL SHOCK, IMPROPER APPLICATION OR INSTALLATION.
NOTE: All CAUTIONS and WARNINGS are identified by the symbol. All warnings are printed in bold capital letters.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.
1.
UNPACKING:
The amplifier was carefully checked before leaving the factory. Inspect shipping container and unit carefully for indication of improper handling. If
the unit has been damaged, make an immediate claim to the carrier.
2.
MOUNTING INSTRUCTIONS:
The amplifier is provided with five mounting feet for placement on a shelf and comes equipped with a Rack Mount Kit (PA-RMK) for mounting in
standard EIA 19” racks. Refer to Figure 7 for mounting instructions.
CAUTION: These devices are not intended for use in hazardous locations as defined by the National Electrical Code (NEC).
3.
POWER AND GROUNDING (SEE FIGURE 1):
The 115VAC line cord has a three-prong plug which should be plugged into a three wire grounded electric outlet. It is very important to maintain
the amplifier ground for safe and trouble-free operation. If there is no grounded electric outlet, connect a wire from the GND terminal on the
OUTPUT terminal strip to a water or steam pipe.
4.
POWER SWITCH AND RECEPTACLE (SEE FIGURE 1):
The ON/OFF power switch located on the rear panel, controls both the internal power of the amplifier and the accessory IEC female outlet.
Note: The accessory to be attached and controlled by the ON/OFF switch must not exceed 3 Amps at 115VAC.
Figure 1: Power Connections
Copyright 1996 Wheelock, Inc. All rights reserved.
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5.
SPECIFICATIONS:
Description
1. Power Output
at 1KHz
2. Total Harmonic
Distortion
3. Outputs
PA-250
Table: 1
PA-500
Tolerance
250 Watts RMS
500 Watts RMS
±1dB
Inputs
4. Impedance
5. Sensitivity
6. Frequency
Response
7. Signal to Noise
Ratio
8. Type of Input
9 Booster Out
10. Controls
11. Indicators
12. Regulation
13. RFI Protection
14. Input Power
15. Consumption
16. Environmental
17.
18.
19.
20.
21.
Weight
Dimensions
FCC
UL
CSA (Pending)
1% at Full Rated Output at 1KHz
250 Watts
500 Watts
8 Ohms, 25V, 70.7V, 100V
Line In
10K Ohms
±1%
±1dB
-----------
1V
Line ±20%
50Hz-20KHz
±2dB
75dB
-3dB
Unbalanced (10K Ohms)
-----Buffered Line In (150 Ohms Zout)
Volume Control
Green LED - Power On
Output Peak Indicator
No Load to Full Output
-----Less than 2dB
RFI Test: Use CB Transmitter Output
in Same Room - Minimum 20 Ft. from
Do Not Operate with
Amplifier - No Pickup.
NO LOAD
90V-132VAC
50/60Hz
Power Factor
Corrected
-----350 Watts
700 Watts
0 Degrees C-49 Degrees C
85% R.H.
Noncondensing
----------21.1
25.2 lbs.
3.5"(H)
17"(W)
14"(D)
----------Part 15
-----813
-----CAN/CSA C22.2 No. 1-M-90
Comments
90-132VAC
50Hz/60Hz
Rated Output
at 1KHz at 8 Ohms
-----Isolated to 1500V
at 1KHz
To Produce
Rated Output
Ref. 1KHz at 1W
-3dB Roll-Off
No "Hum"
Not Weighted
-----Phono Jack
Front Panel
Front Panel
Amp
Stability
Amp
Stability
-----------
-----------
Rack Mount 19"(W)
----------------
INPUT CONNECTIONS:
6.
LINE IN (SEE FIGURE 2):
Connect line level audio source (i.e. MIC/LINE mixer) to the LINE IN phono jack. For balanced line level source, connect to 600 OHM terminal
block. Note: The 600 OHM from the terminal block is disconnected when a phone plug is inserted in the LINE IN phono jack.
7.
BOOSTER OUT (SEE FIGURE 2):
The BOOSTER OUT signal allows for cascading amplifiers. The BOOSTER OUT is the LINE IN signal buffered and available at the BOOSTER
OUT phono jack.
Figure 2: Input Connections for PA-250 and PA-500
OUTPUT CONNECTIONS (FIGURE 3):
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8.
AUDIO OUT (SEE FIGURE 3):
Connect (2) output wires from the speaker load, to the COM screw terminal and the selected constant voltage terminal, (i.e. 25V, 70.7V or 100V).
The constant voltage distribution method facilitates the use of multiple speakers in parallel with a single amplifier. Note that each speaker must
have its own 25V, 70.7V or 100V line-matching transformer. Select the wattage tap on the line matching transformer of each speaker for the
power (volume) desired. An 8 Ohm speaker load may be connected to the COM and the 8 Ohm terminals. The audio output is available at the
rated output of 250 or 500 Watts for an 8 Ohm load, for a 25V, 70.7V or 100V. The GND terminal of the AUDIO OUT terminal block is chassis
ground. The shield of audio output shielded cable should be terminated to this GND (if applicable). The COM and GND of AUDIO OUT terminal
are connected to chassis ground.
Note: The wattage rating of the speaker loads should not exceed total power rating of the amplifier. The following Table 2 below will provide the
appropriate line loss that should be calculated for those expected speaker loads.
CAUTION: Do not operate amplifier without a proper load attached to audio out terminals.
CAUTION: Do not connect, disconnect wiring or cabling with power applied.
9.
AWG
Size
10
12
14
16
18
20
22
PROPER WIRE SIZE/LENGTH:
To minimize power loss in the system cabling, use a wire gauge suitable for the power being distributed and the length of cable. Use the following
table as a guide.
Max
Power
AWG
Per NEC
Per NEC
1,060W
420W
210W
70W
35W
Table 2: 2 Wire Copper Cable Lengths for Speaker Lines at 0.5dB Loss in SPL
(12.5% Power Loss in Watts)
Low Impedance
70 Volt Speaker Line
Speaker Line
Nominal Power in the Load Length in Feet
8 Ohms
10W
15W
20W
40W
60W
100W
125W
200W
240
15,000
9,900
7,500
3,750
2,500
1,500
1,180
730
150
9,100
6,200
4,680
2,340
1,560
940
730
460
95
5,600
3,800
2,880
1,440
960
600
450
280
60
3,600
2,400
1,870
930
620
370
290
180
40
2,300
1,500
1,150
570
380
230
180
110
25
1,400
960
730
360
240
---------15
900
600
460
----------------
AWG
Size
250W
590
370
220
140
----------
400W
370
230
140
90
----------
500W
290
180
110
-------------
10
12
14
16
18
20
22
Notes:
1) For 25V line divide all 70.7V lengths by 8. 2) For 100V line multiply all 70.7V lengths by 2.0. 3) To allow for future expansion and distribution cable
line loss, it is recommended that the total system wattage should not exceed 85% of the amplifier’s rated output. (i.e. 212 and 425 Watts for the PA-250
and PA-500 respectively). 4) The total system wattage requirement is the summation of the wattage tap selections of all system speakers and horns.
Figure 3: Output Connections
WARNING: THE COVER FOR THE 100V AUDIO OUTPUT TERMINAL MUST BE ATTACHED AT ALL TIMES. THE POWER CORD MUST BE
DISCONNECTED BEFORE CONNECTING TO THE 100V TERMINAL. THE COVER MAY BE REMOVED TO CONNECT A WIRE TO THE
TERMINAL, BUT IT MUST BE REATTACHED AFTER CONNECTING THE WIRE(S). FAILURE TO MAINTAIN THE TERMINAL COVER IN PLACE
COULD EXPOSE YOU AND/OR OTHERS TO ELECTRICAL SHOCK WHICH COULD RESULT IN SERIOUS INJURY AND/OR DEATH.
10. CASCADING AMPLIFIERS (SEE FIGURE 4):
The BOOSTER OUT of the PA-250 or PA-500 amplifier, which is the buffered LINE IN audio signal, can be used as a LINE IN input to additional
PA-250’s or PA-500’s to expand existing systems or to distribute large speaker loads.
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Figure 4: Cascading Amplifiers
Note: Use shielded cable for all interconnections.
OPERATION:
WARNING: DO NOT OPEN COVER! NO USER SERVICEABLE INTERNAL COMPONENTS! REFER TO QUALIFIED SERVICE TECHNICIAN. IF
UNIT IS OPENED, WARRANTY IS VOIDED.
Figure 5: PA-250 or PA-500 Front Panel
11.
POWER INDICATOR:
Green LED indicator illuminates when AC power is applied to the amplifier.
12.
VOLUME CONTROL:
Adjusts the total output level of the amplifier.
13.
OUTPUT PEAK INDICATOR:
The indicator, as the amplifier output is increased, illuminates within 2dB of full rated output.
14.
15.
Figure 6: PA-250 or PA-500 Rear Panel
POWER ON/OFF SWITCH AND RECEPTACLE:
The amplifier is designed to operate from a line voltage of 115VAC at 50/60Hz. The IEC 320 receptacle has a male input to connect a grounded
line cord and female output for attaching a switched external auxiliary load. The external auxiliary load is not to exceed 3 Amps at 115VAC.
AUDIO OUT OUTPUTS:
The audio output is available at the rated output of 250 Watts (PA-250) or 500 Watts (PA-500) for an 8 Ohm load, for a 25V, 70.7V or 100V. The
GND and COM terminals of the AUDIO OUT terminal block are chassis ground. The shield of the audio shielded cable is to be terminated to this
GND. Connect (2) output wires from the speaker load, to the COM screw terminal and the selected constant voltage terminal, (i.e. 25V, 70.7V or
100V). The constant voltage distribution method facilitates the use of multiple speakers in parallel with a single amplifier. Note: Each speaker
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must have its own 25V, 70.7V or 100V line-matching transformer. Select the wattage tap on the line matching transformer of each speaker, for the
power (gain) desired. An 8 Ohm speaker load may be connected to the COM and the 8 Ohm terminals.
16.
LINE LEVEL IN/OUT:
LINE IN is a high impedance line level input into phono jack; 600 Ohm is a balanced screw terminal input. When a phono plug is inserted into the
LINE IN phono jack the balanced input is disconnected. The BOOSTER OUT is the LINE IN signal buffered and available at a phono jack.
17.
RACK MOUNT ATTACHMENT:
1. Mounting hardware for the PA-RMK is supplied.
(2) Handle Brackets
(8) #10-16 1/2” Screws
2. Using a #2 Phillips head screwdriver, remove (4) screws located on each side of the cover.
3. Attach mounting bracket with screws supplied as shown in Figure 7.
Figure 7: Rack Mount Attachment
CAUTION: Do not block air flow, stack units or operate vertically. When rack mounting, it is necessary to have a minimum of 1.75” above and 1.75”
below unit to allow for adequate air flow. Failure to do so could result in excessive heat which could damage the amplifier.
18.
TROUBLESHOOTING:
Symptom
No Output
Low, High, or Distorted Level
Possible Solution
- Verify unit is receiving AC power.
- Check input source functionality and level.
- Output may not be connected or connected incorrectly.
- Input signal may be too high or too low.
- Check gain control on unit.
- Input or output impedance may be mismatched.
NOTE: This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of FCC Rules. These limits
are designed to provide reasonable protection against harmful interference when this equipment is operated in a commercial environment. This
equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his/her own expense.
This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus set out in the Radio Interference Regulations of
the Canadian Department of Communications.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites applicables aux appareils numériques de la class A
prescrites dans le Règlement sur le brouillage radioélectrique édicté par le ministère des Communications du Canada.
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Limited Warranty
Wheelock products must be used within their published specifications and must be PROPERLY specified, applied, installed, operated, maintained and
operationally tested in accordance with these instructions at the time of installation and at least twice a year or more often and in accordance with local,
state and federal codes, regulations and laws. Specification, application, installation, operation, maintenance and testing must be performed by qualified
personnel for proper operation in accordance with all of the latest National Fire Protection Association (NFPA), Underwriters' Laboratories (UL),
Underwriters’ Laboratories of Canada (ULC), National Electrical Code (NEC), Occupational Safety and Health Administration (OSHA), local, state,
county, province, district, federal and other applicable building and fire standards, guidelines, regulations, laws and codes including, but not limited to, all
appendices and amendments and the requirements of the local authority having jurisdiction (AHJ). Wheelock products when properly specified, applied,
installed, operated, maintained and operationally tested as provided above are warranted against mechanical and electrical defects for a period of three
years from date of manufacture (as determined by date code). Correction of defects by repair or replacement shall be at Wheelock's sole discretion and
shall constitute fulfillment of all obligations under this warranty. THE FOREGOING LIMITED WARRANTY SHALL IMMEDIATELY TERMINATE IN THE
EVENT ANY PART NOT FURNISHED BY WHEELOCK IS INSTALLED IN THE PRODUCT. THE FOREGOING LIMITED WARRANTY SPECIFICALLY
EXCLUDES ANY SOFTWARE REQUIRED FOR THE OPERATION OF OR INCLUDED IN A PRODUCT.
WHEELOCK MAKES NO
REPRESENTATION OR WARRANTY OF ANY OTHER KIND, EXPRESS, IMPLIED OR STATUTORY WHETHER AS TO MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE OR ANY OTHER MATTER.
USERS ARE SOLELY RESPONSIBLE FOR DETERMINING WHETHER A PRODUCT IS SUITABLE FOR THE USER'S PURPOSES, OR WHETHER
IT WILL ACHIEVE THE USER'S INTENDED RESULTS. THERE IS NO WARRANTY AGAINST DAMAGE RESULTING FROM MISAPPLICATION,
IMPROPER SPECIFICATION, ABUSE, ACCIDENT OR OTHER OPERATING CONDITIONS BEYOND WHEELOCK'S CONTROL.
SOME WHEELOCK PRODUCTS CONTAIN SOFTWARE. WITH RESPECT TO THOSE PRODUCTS, WHEELOCK DOES NOT WARRANTY THAT
THE OPERATION OF THE SOFTWARE WILL BE UNINTERRUPTED OR ERROR-FREE OR THAT THE SOFTWARE WILL MEET ANY OTHER
STANDARD OF PERFORMANCE, OR THAT THE FUNCTIONS OR PERFORMANCE OF THE SOFTWARE WILL MEET THE USER'S
REQUIREMENTS. WHEELOCK SHALL NOT BE LIABLE FOR ANY DELAYS, BREAKDOWNS, INTERRUPTIONS, LOSS, DESTRUCTION,
ALTERATION, OR OTHER PROBLEMS IN THE USE OF A PRODUCT ARISING OUT OF OR CAUSED BY THE SOFTWARE.
THE LIABILITY OF WHEELOCK ARISING OUT OF THE SUPPLYING OF A PRODUCT, OR ITS USE, WHETHER ON WARRANTIES, NEGLIGENCE,
OR OTHERWISE, SHALL NOT IN ANY CASE EXCEED THE COST OF CORRECTING DEFECTS AS STATED IN THE LIMITED WARRANTY AND
UPON EXPIRATION OF THE WARRANTY PERIOD ALL SUCH LIABILITY SHALL TERMINATE. WHEELOCK IS NOT LIABLE FOR LABOR COSTS
INCURRED IN REMOVAL, REINSTALLATION OR REPAIR OF THE PRODUCT BY ANYONE OTHER THAN WHEELOCK OR FOR DAMAGE OF ANY
TYPE WHATSOEVER, INCLUDING BUT NOT LIMITED TO, LOSS OF PROFIT OR INCIDENTAL OR CONSEQUENTIAL DAMAGES. THE
FOREGOING SHALL CONSTITUTE THE SOLE REMEDY OF THE PURCHASER AND THE EXCLUSIVE LIABILITY OF WHEELOCK.
IN NO CASE WILL WHEELOCK'S LIABILITY EXCEED THE PURCHASE PRICE PAID FOR A PRODUCT.
Limitation of Liability
WHEELOCK'S LIABILITY ON ANY CLAIM OF ANY KIND, INCLUDING NEGLIGENCE AND BREACH OF WARRANTY, FOR ANY LOSS OR DAMAGE
RESULTING FROM, ARISING OUT OF, OR CONNECTED WITH THIS CONTRACT, OR FROM THE MANUFACTURE, SALE, DELIVERY, RESALE,
REPAIR OR USE OF ANY PRODUCT COVERED BY THIS ORDER SHALL BE LIMITED TO THE PRICE APPLICABLE TO THE PRODUCT OR PART
THEREOF WHICH GIVES RISE TO THE CLAIM. WHEELOCK'S LIABILITY ON ANY CLAIM OF ANY KIND SHALL CEASE IMMEDIATELY UPON THE
INSTALLATION IN THE PRODUCT OF ANY PART NOT FURNISHED BY WHEELOCK. IN NO EVENT SHALL WHEELOCK BE LIABLE FOR ANY
CLAIM OF ANY KIND UNLESS IT IS PROVEN THAT OUR PRODUCT WAS A DIRECT CAUSE OF SUCH CLAIM. FURTHER, IN NO EVENT,
INCLUDING IN THE CASE OF A CLAIM OF NEGLIGENCE, SHALL WHEELOCK BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE PRECEDING
LIMITATION MAY NOT APPLY TO ALL PURCHASERS.
7/96
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