User Manual - JW Davis & Company
Contents
1. 14 NEW TECHNOLOGY 4 OLD RELIABILITY 20 Davis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com XI SCHEMATIC FOR INPUT MODULES 5 6 XII SCHEMATIC FOR CHASSIS BOARD eH J NEW TECHNOLOGY 4 OLD RELIABILITY 20 Davis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com The Mark of the Professcoudt DA 120M Master Series Amplifier Please Note Thank you for selecting a J W Davis DA 120M Amplifier Since 1933 it has been our goal to produce a complete line of quality products and to offer a FIVE YEAR WARRANTY on most J W Davis items We also promise that you or your customer will not see our products listed in a discount catalog You may sell J W Davis amp Company products with confidence and pride For your next installation please consider the other fine J W Davis products such as power amplifiers pre Amplifiers mixers microphones speakers speaker systems horns lecterns baffles transformers volume controls and accessories Also be sure to check our web site www jwd co2. 1 B L 3a 250 19 eo 120 2400 16 420 30 0 90 30 740 1 500 18 6 39 19 38 76 230 460 920 20 10 1 2 2 48 150 300 600 22 16 2 7 14 28 93 190 380 12 NEW TECHNOLOGY lt gt OLD RELIABILITY f W Davis amp Company e 3030 Canton Street e P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com 5 j 1 R e i a E t 1 t B y 8 11 es Ww 2 gt t Lp ex e INPUTS LM L j dg y cs aa HS FI 4 1 ff Ti y 9 0 m of 44 as a ef 1 an C N x AH rude P T E t 4 d 4 a E e gt 3 aJ I 4 a u 5 1 i A E 1 s i 1 55 t T Lb 5 C 4 zz X SCHEMATIC FOR INPUT MODULES 1 4 f W Davis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com i ASTA 1 1 i33 1 tie Ht OLD RELIABILITY NEW TECHNOLOGY
3. rer A problem arises if one more speaker must be added at some future date as all the connections must be changed This is not a significant problem if only a few speakers are involved But if the network is extensive the problem will magnified Futhermore failure of one speaker can take out a number of associated units HIGH IMPEDANCE OF CONSTANT VOLTAGE 25 AND 70v ai i cse ear ae Lege SYSTEMS 215 8 yr NA The high impedance or constant voltage method of impedance 2 matching uses a high impedance amplifier output which is 58 59 eT transformed down to 8 Ohms by an impedance matching ar qu transformer at each individual speaker The big advantages of this approach as compared to low impedance are 1 Reduced line losses and ability to use smaller wire gauges This is due to the higher voltage and reduced current in the speaker lines 2 Much simpler impedance matching procedures and connections Constant voltage is a misnomer in that the amplifier does not always produce 70V Rather the amplifier output impedance is set at such a level that irrespective of its rated power it will produce70 7 Volts output at full power Thus a 10 Watt amplifier optimum load would have an impedance of 500 Ohms P 70 72 500 a 40 Watt amp would be 126 Ohms and 120 Watt amp 42 Ohms Multiple transformer taps allow the impedance at each speaker to be adjusted individually to give a total matched load Be
4. 6 8 10 12 14 16 INPUT 4 1 Input 4 XLR input jack accepts balanced low impedance signal from microphones mixers wireless micro phone receivers and equipment with compatible signals The input is rated at 1506 1mV 2 Input 4 terminal strip input accepts balanced low Impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 150Q 1mV 3 Input 4 dip switch allows four selections auxillary AUX screw terminal T XLR F J and 17VDC phantom power PHANTOM 4 Input 4 features two RCA jacks that electronically combine stereo or two NOTE Only one input channel audio into a mono signal To input a single mono signal either RCA on the dip switch Micro jack may be used The input is rated at 47kO at 100mV phone XLR Microphone Screw Terminal or Auxil INPUT 3 iary should be selected 5 Input 3 features two RCA jacks that electronically combine stereo or two at any given time Se channel audio for a mono signal To input a single mono signal either RCA lecting more than one jack may be used The input is rated at 47kO at 100mV input will cause a distor 6 Input 3 dip switch allows four selections auxillary AUX screw terminal T tion and a drop in the in XLR F J and 17VDC phantom power PHANTOM put signal 7 Input 3 terminal strip input accepts balanced low impedance signal from microphones mixers wireless microphone
5. MOH output will remain controlled by the volume control located at the MOH input 21 Input 5 has an additional input for DVD or CD The input is rated at 47kQ 360mV INPUT 6 22 Input 6 features two RCA jacks that electronically combine stereo or two channel audio into a mono signal To input a single mono signal either RCA jack may be used The input is rated at 47kQ at 100mV 23 Input 6 dip switch allows four selections auxillary AUX screw terminal T XLR F J and 17VDC phan tom power PHANTOM 24 Input 6 terminal strip input accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 150Q 1mV 25 Input 6 XLR input jack accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 1509 1mV 6 NEW TECHNOLOGY 4 OLD RELIABILITY UW Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 e Fax 800 388 9106 e Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark ad the Professcoudt 26 Pre Out Power In The two RCA jacks offers an opening between the pre amp and the power section of the amplifier This allows the insertion of an equalizer or other signal conditioning equipment Unbalanced 27 Tape Recording Output Unbalanced 1 Volt 600Q 28 Boo
6. eliminates the need to remove cover Installation expansion requiring greater power is accomplished through a booster output jack which allows the signal from the DA 120M to be connected to the input of an additional amplifier A master volume control is provided for overall control of the microphone and auxiliary outputs Bass and treble controls permit adjustment of voice and music output Paging horn protection from damage against overdriving the lower frequencies is provided by 400Hz high pass filter VOX muting is available for MIC 1 and System OverRide by activation at the board level The DA 120M may be rack or wall mounted using optional accessory kit RAK 120A M or WM 120M NOTE If the Amplifier is frequently moved to different locations or used as a portable system the XLR connectors should be used The action of plugging and unplugging the connector maintains a good connection If the amplifier is installed ina permanet location the phoenix type screw terminals should be used for a better long term connection 4 NEW TECHNOLOGY 4 OLD RELIABILITY UW Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com The Mark of the Professional IV BACK PANEL DETAIL 3 3 a RED OS 220 9 Mit ry 38 7 38 37 38 B4 id f 11 13 15 e 1 4
7. it is important to present the amplifier with the load impedance it is designed to handle Failure to do this can cause overheating and component failure In many cases problems can take months to appear in the form of reduced intelligibility and unnecessary service calls A load impedance that is too low is especially bad Strive to have a load impedance of not less than 80 of the chosen amplifier output impedance Do not connect a 4 ohm speaker to the 8 ohm output Driving a load of higher impedance than rated amplifier output is not as serious but results in a power loss proportional to the mismatch and should be avoided For example driving a 16 ohm load through the 8 ohm output will result in a 50 loss in power The high impedance mismatch should be kept to less than 200 especially if it is anticipated that more than 50 of the rated amplifier power will be required There are two methods of connecting groups of speakers to the amplifier First using low impedance i e 4 8 16 ohm outputs This is preferable where a Runs are short less than 200 ft 70 m b Few horns or speakers are to be used ie typically 4 8 c Same sound levels are required at each speaker d Low impedance also provides slightly better fidelity and frequency response High impedance or constant voltage is the second method and is preferable where a The runs are long and line losses are to be avoided b Many speakers are to be used c Different soun
8. receivers and equipment with compatible signals The input is rated at 15042 1mV 8 Input 3 XLR input jack accepts balanced low impedance signal from microphones mixers wireless micro phone receivers and equipment with compatible signals The input is rated at 1506 1mV INPUT 2 9 Input 2 XLR input jack accepts balanced low impedance signal from microphones mixers wireless micro phone receivers and equipment with compatible signals The input is rated at 1506 1mV 10 Input 2 terminal strip input accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 15042 1mV 11 Input 2 dip switch allows four selections auxillary AUX screw terminal T XLR F J and 17VDC phantom power PHANTOM 12 Input 2 features two RCA jacks that electronically combine stereo or two channel audio into a mono signal To input a single mono signal either RCA jack may be used The input is rated at 47kQ at 100mV 5 NEW TECHNOLOGY 42 OLD RELIABILITY UW Davis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com The Mark ad the Professional INPUT 1 13 Input 1 features two RCA jacks that electronically combine stereo or two channel audio into a mono signal To input a single mono signal either RCA ja
9. signal The third dip switch designated J activates the microphone XLR input Do not use the phoenix type microphone input at the Figure 1 same time as this will degrade the signal The fourth dip switch designated Phantom activates the phantom power needed for condenser microphones If the phantom power is left on it will not harm the dynamic microphones but should be turned off for safety measures when not in use Three additional dedicated inputs with volume controls are located on the back panel The Master Vol ume Control or the Bass and Treble Controls do not affect the following three inputs 1 Telephone Page input that accepts the signal directly from the page port out on the telephone system 2 Music On Hold built in one watt amplifier that provides music and information to the telephone hold system The same infromation may be routed to the main amplifier for distribution to the entire sound system via input 5 3 System OverRide SOR input default setting is for sound masking This input is not affected by the tone controls or any other function of the amplifier The sound masking may be equalized before using the other amplifier functions However the input also may be changed by a jumper on the circuit board to become a priority input for the system d NEW TECHNOLOGY 4 OLD RELIABILITY Y W Dauis d Company 3030 Canton Street PO Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 80
10. the six MIC AUX inputs ACTIVATION OF MICROPHONE 1 VOX MUTING To give microphone 1 precedence over microphones 2 6 change the jumper JP 205 to the ON posi tion and jumper JP 203 to the OFF Mute MIC One position These jumpers are located on the rear of the lower circuit board for easy access Fig ure 3 This feature is especially useful where a conference chair man a podium speaker a dispatcher or other speaker may require primary access to the system Figure 3 ACTIVATION OF THE SYSTEM OVERRIDE INPUT TO BECOME A PRIORITY INPUT The default setting of the System OverRide is for sound p masking applications Jumper JP 301 Figure 4 will allow the Signal OverRide to become a priority input and mute all inputs except the Music On Hold to the telephone system The jumper is located on the upper circuit board close to the SOR input Figure 4 NEW TECHNOLOGY 4 OLD RELIABILITY f W Davis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark of the Professional VI TECHNICAL SPECIFICATIONS DA 120M 120 Watts Continous 33dB 60Hz 15kHz Frequency Response Tel 3dB 250Hz 15kHz Mic gt 60dB Telephone gt 60dB Aux gt 75dB CD DVD gt 75dB MOH 75dB SOR gt 75dB THD lt 1 Mic XLR 6 150 Ohm 1mV Mic Terminal 6 150 Ohm 1mV Unbal
11. 0 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark of the Professional A separate internal 1 watt amplifier is used to provide the music on hold functions which permits close control of volume levels The music on hold RCA type input shown in Figure 2 allows the signal from music tape messages company advertisements or other sources to feed the music on hold amplifier The output also may be routed to include the main amplifier for general distri bution using the switch in Figure 2 Paging with VOX muting may be accomplished either from microphone one io input or through the telephone input a feature desirable in installations such as 5 Q 77 hospitals airports and auto dealerships where paging may be required from 40 multiple locations Figure 2 A wide range of background music and audio visual programming applications are supported through the CD DVD input and the six AUX inputs For applications requiring recording of program material a special tape out jack is available Applications such as priority signaling and sound masking that must not be interrupted by the regular functions of the amplifier are possible through the dedicated System OverRide input control that is independent of the master bass or treble controls An equalizer or other signal modifying devices may be easily inserted by an external pre amp input output jack An external dip switch for phantom power
12. Positive voltage applied to the terminal will result in a forward or outward movement of the speaker cone If using speakers which are unmarked or using speakers from various manufacturers the following procedure will provide a fast and simple test for polarity 1 Connect one side of a 9 Volt battery to one speaker terminal 2 Momentarily connect the other side fo the battery to the other speaker terminal 3 Note the direction of the cone movement inward or outward If the cone movement is inward backward reverse the battery leads 4 Mark the speaker terminal connected to the positive side fo the battery as positive 5 Repeat the procedure for each successive speaker to ensure that the cone movement is forward outward in each case XIX POWER LOSS IN LONG LINES For long lines the power loss in watts becomes a significant factor The power supplied by the amplifier is effectively reduced by the line loss For a 0 5 dB loss in sound pressure the total wire resistance must be limited to 6 of speaker impedance The table below shows the calculated two wire cable lengths permissible for a number of wire sizes in feet For a 1 dB loss the lengths may be doubled For 2 dB loss multiply by 4 4 High Impedance Systems Low Impedance awg Resistance 100W 70 7V laeso 25W 70 7V Size ohms 1000 4 ohms 8 ohms 16 ohms 12 5W 25V 6 25W 25 3 5W 25 5 Feet 50 ohms 100 ohms 200 ohms
13. The Mark of the Professional USER S MANUAL DA 120M Master Series Amplifier Unpacking Inspection Procedures 2 Vil PA Speaker Layout Il Product Features VIII Polarity Ill Product Description IX Power Loss in Long Lines IV Back Panel Detail X Schematic for Input Modules 1 4 13 V Circuit Board Level Settings XI Schematic for Input Modules 5 6 14 VI Technical Specifications XII Schematic for Chassis Board 090705122 NEW TECHNOLOGY 4 OLD RELIABILITY O W Dauis amp Company 3030 Canton Street PO Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark ad the Professional WARNING DO NOT CUT OR REMOVE THE GROUND PIN ON THE AC POWER h CABLE DO NOT USE AC TWO PIN ADAPTER UNLESS IT IS GROUNDED BY AN EXTERNAL GROUND WIRE CHECK THE AC WALL RECEPTACLE TO CONFIRM THE PROPER GROUND IS PRESENT WARNING TO REDUCE THE RISK OF ELECTRICAL SHOCK DO NOT REMOVE n THE COVER NO USER SERVICEABLE PARTS INSIDE REFER SERVICING TO QUALIFIED SERVICE PERSONNEL 4 WARNING TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE I UNPACKING AND INSPECTION PROCEDURES This unit was carefully checked and packed before leaving the factory However the shipping con tainer and unit should be inspected for indications of improper handling If the unit has b
14. anced Aux 6 Electronically Summed 47k Ohm 100mV Inputs Unbalanced DVD CD Electronically Summed 47k Ohm Unbalanced ERU Unbalanced MOH 47k Ohm 100mV Unbalanced SOR 47k Ohm 100mV Tel Transformer Balanced 600 Ohm 100mV Unbalanced Power In 47k Ohm 1 V Microphone Phantom Power 6 17 VDC Dip Switchable Speaker 8 Ohm or Transformer Speaker 25 V 5 2 Ohm or 70 7 V 42 Ohm MOH 600 Ohm 0 1 V adjustable Unbalanced Tape Out 600 Ohm 1 Volt Unbalanced Booster Out 600 Ohm 1 Volt Unbalanced Pre Out 600 Ohm 1 Volt Telephone VOX 37dB Mute Circuits Mic 1 VOX 37dB Via Jumper 205 203 SOR VOX 37dB Via Jumper 301 Bass 100Hz gt 10dB Treble 10kHz gt 10dB High Pass Filter switchable 400Hz 6dB Octave S N Ratio tone controls flat 115VAC Power Source 24VDC Power Consumption 360VA Thermal Control 3 Thermally Controlled Variable Speed Fan Weight 19 8 Ibs Shipping Weight 23 5 Ibs RAK 120A M Rack Mount Kit WM 120M Wall Mount Kit Power On Multi Colored LED Output Meter NEW TECHNOLOGY OLD RELIABILITY Dauis amp Company 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com P o gt The Mark ad the Professional XII CONSIDERATIONS FOR PA SPEAKER LAYOUT SPEAKER CONNECTIONS In connecting speakers to a public address amplifier
15. cause of the high impedance arrangement the system is easier to impedance match and is also inherently less susceptible to problems caused by mismatching The transformer taps are marked in W watts instead of Ohms usually 4 2 1 2 Again it should be born in mind that these levels of power output are only achieved when the transformer is working at 70 7 Volts The transformers are connected in parallel A good match is obtained by ensuring that the total of all tap settings fits into the range of 40 80 of rated amplifier output 80 is chosen to allow for trans former insertion loss Also It is good practice not to drive the amplifier to 100 of its capacity Examples are shown below For simplicity it is assumed that all tap settings are the same at each speaker For a 120 Watt amplifier the range 40 8096 is equivalent to 48 96 Watts Therefore 18 speakers x 4 Watt taps each 72W Good match 12 speakers x 1 Watt taps each 12W Poor match 60 speakers x 1 Watt taps each 60W Good match 60 speakers x 4 Watt taps each 240W Very poor match overload 90 speakers x 1 Watt taps each 90W Good match NOTE None of the above tap settings guarantee the actual sound levels through each speaker This is a function of the master volume control as well as the tap setting The tap setting simply defines the maximum power consumed by an 8 Ohm speaker if presented with 70 7 Volt input In syste
16. ck may be used The input is rated at 47kQ at 100mV 14 Input 1 dip switch allows four selections auxillary AUX screw terminal T XLR F J and 17VDC phan tom power PHANTOM 15 Input 1 terminal strip input accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 150Q 1mV 16 Input 1 XLR input jack accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 1500 1mV INPUT 5 17 Input 5 XLR input jack accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 15042 1mV 18 Input 5 terminal strip input accepts balanced low impedance signal from microphones mixers wireless microphone receivers and equipment with compatible signals The input is rated at 15042 1mV 19 Input 5 dip switch allows four selections auxillary AUX screw terminal T XLR F J and 17VDC phan tom power PHANTOM 20 Input 5 features two RCA jacks that electronically combine stereo or two channel audio into a mono signal To input a single mono signal either RCA jack may be used The input is rated at 47kQ at 100mV NOTE If the Music On Hold is switched to main amp no other inputs on Aux 5 can be used The controls for Input 5 on the front will apply The
17. d levels are required at different locations for example indoor speakers and outdoor horns d Future expansion possibilities require flexibility in wiring layout The following is a more detailed discussion of these two methods LOW IMPEDANCE CONNECTION The speakers must be connected to present a combined impedance equal to the selected ampli fier output impedance i e 4 8 16 ohms The connections should be arranged in a series parallel combination to achieve this according to the following formula The impedance should be be tween 7096 and 20096 of the output impedance selected If the amplifier is to be driven anywhere near its full rated output the impedance should be well within these tolerances SERIES PARALLEL COMBINATIONS In larger systems it will be necessary to combine series and parallel connections to obtain the necessary impedance The rule for calculating the total effective impedance is to divide the entire circuit into indi vidual small series of parallel sub circuits and apply the foregoing rules to them 10 NEW TECHNOLOGY 4 OLD RELIABILITY f 20 Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com ie Wer of he Passat The following is an example using 16 8 Ohm speakers Each schematic is an impedance equivalent to its predecessor but has been simplified
18. een damaged in transit make an immediate claim to the carrier for their inspection Returning the freight to J W Davis amp Company will void your claim with the carrier ll FEATURES The features and benefits listed below make this a unique amplifier designed with the user s needs in mind to be a product that is universal and fits many applications without modifications or additional equip ment e 7 Major Application Interfaces e 6 Switchable Microphone AUX Inputs e 15 Special Signal Inputs e 7 Signal Outputs e 120 Watts RMS Power e 8 Ohm 25 and 70 Volt System Outputs e 24 VDC Alternate Power Source e Multiple Music On Hold Options e A switch to activate the 400Hz roll off circuit to protect horn drivers e Tape out for recording e Pre out Main In for insertion of signal conditioning equipment such as equalization e Booster out provides a signal for power amplifiers to expand the system e FIVE YEAR WARRANTY 2 NEW TECHNOLOGY 4 OLD RELIABILITY Y W Dauis d Company 3030 Canton Street PO Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark ad the Professional lil DESCRIPTION The JWD Master Series of monaural amplifiers provide the combination of interface signal control and extended mixer capacity required by professional audio system integration In addition to traditional commercial sound applica
19. m for additional manufacturers products that we distribute PURCHASE INFORMATION FOR YOUR RECORDS DA 120M SERIAL PURCHASE DATE INSTALLATION DATE PURCHASED FROM ADDRESS CITY amp STATE TELEPHONE NAME NEW TECHNOLOGY 4 OLD RELIABILITY 20 Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com
20. ms with a small number of speakers it is always preferable to use a high tap setting and reduce the sound level by turning down the master volume control In calculating the amplifier rating needed for a typical music paging system using speakers distributed to an office environment a good rule of thumb is to allow about one watt per speaker and space speakers at 177 x ceiling height For noisy areas or where the volume level required is higher more power is required 11 NEW TECHNOLOGY 4 OLD RELIABILITY W Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales jwd com www jwd com The Mark of the Professional Vill POLARITY When using multiple speakers in a sound system installation one must observe proper polarity of the speakers in order to prevent the cancellation effects caused by adjacent speakers being in reverse polarity Speakers in reverse polarity will lose much of their normal volume and produce poor tonal quality For speakers facing in the same general direction all soeaker cones should move in unison in the same direction When two speakers face each other the cone of one speaker should more inward when the other speaker cone moves outward All JWD speakers have the hot terminal marked with a or a red dot The common terminal is either unmarked or marked with a
21. ster Out Unbalanced 1 Volt 600Q 29 Telephone Page Volume Control Controls the page volume and is unaffected by the other controls 30 Telephone Page Input The transformer coupled telephone input terminals will accept a balanced 3 Wire or unbalanced 2 Wire line direct from the telephone page port out talk battery without ring VOX muting of inputs 1 6 during page G Sleeve COM Ring HOT Tip Transformer Balanced 600Q 31 Music On Hold Output Music commercials or other information may be fed to the telephone system and to the main amplifier if desired 60042 1 Volt adjustable 32 Music On Hold Volume Control Controls the volume of the MOH output and is unaffected by the other controls 33 Switch Music On Hold to Main Amp The switch allows the same information on the MOH input to be used by the Main Amplifier NOTE No other inputs on Aux 5 can be used The controls for Input 5 on the front will apply The MOH output will remain controlled by the volume control located at the MOH input 34 Music On Hold Input RCA Connector Input for music commercials or other information 47kO 100mV 35 System OverRide SOR Connector Input for sound masking The input may be changed by a jumper on the circuit board to become a priority input for the system The SOR input is not affected by the tone con trols master volume control or any other function of the amplifier The sound masking may be set up and equalized before
22. the other functions of the amplifier are used Unbalanced 47k 100mV 36 System OverRide Volume Control Controls the volume of System OverRide output of the amplifier 37 High Pass Filter Switch When the switch is in the ON position the output signal will roll off frequencies of 400Hz and below Eliminating the lower frequencies will help prevent damage to the voice coil diaphram of horns 38 Receptacle for 115V Power Cable Built in 5A 250V Replaceable Fuse 39 Chassis Ground Terminal 40 24VDC Power Input The 24 VDC allows the amplifier to be used with emergency backup power supplies portable use or where 115VAC is not available 41 Speaker Output Terminals The available screw terminal outputs are 8G 25V or 70V Only one output should be used at a time 7 NEW TECHNOLOGY 4 OLD RELIABILITY UW Davis amp Company e 3030 Canton Street P O Box 710219 Dallas Texas 75371 0219 Sales 800 527 5705 e Fax 800 388 9106 Corp 214 651 7341 Fax 214 939 0328 sales 9 jwd com www jwd com ia Mane of te Profesional VI CIRCUIT BOARD LEVEL SETTINGS FOR ADDITIONAL FEATURES WARNING The following changes should be made only by a qualified AN technician to avoid the risk of electrical shock and of voiding the warranty due to improper circuit wiring ACTIVATION OF TELEPHONE VOX MUTING The default setting of the DA 120M is shipped from the factory with the telephone VOX mute activated and will mute
23. tions such as paging and background music the Master Series extends the scope of capabilities to include integration with telephone communications audio visual security sound masking and digital devices that previously have been available only in more complex modular amplifiers All features are inclusive without requiring additional accessories or modifications The front panel has nine controls Six front panel volume controls to individually control dip switchable microphone or auxiliary inputs located on the back panel a bass and a treble control plus a master volume control In addition the power switch and LED signal overload indicators are located on the front panel for easy access The back panel contains the six microphone auxiliary input modules matching the six front panel volume controls All are similar to Figure 1 except for input module 5 which has two additional RCA jack inputs for CD or DVD The first dip switch shown in Figure 1 designated AUX activates the auxiliary input This aux input consists of two RCA jacks marked AUX with an input number and unbalanced that electronically combine stereo or two channel audio for a mono signal To input LI A 2 single mono signal either RCA jack may be used CAUTION SELECT ONE MHPUT ONLY G COM HOT The second dip switch designated T activates the phoenix type microphone input Do not use the XLR connector at the same time as this will degrade the
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