user`s manual ALC4
Contents
1. 5 amplified loudspeaker controller p WP 2 A a wha a La is af a af a user s manual evolutionary audio solutions Table of contents Introduction Important safety instructions Precautions Installation Overview Connections Operation Safety Service and support 10 Specifications 11 Block diagram oo0o o0o00P BoQNa2 1 Introduction Dear customer Congratulations on your purchase of an Alcons Audio ALC4 professional power amplifier and thank you for your confidence in Alcons products We are very honoured to welcome you to the growing family of Alcons ambassadors For your safety please read the Important safety instructions and the Precautions section before installing and operating the amplifier The ALC4 Amplifier Loudspeaker Controller is a combination of a loudspeaker controller and a high efficiency power amplifier The ALC4 is designed to guarantee the best loudspeaker drive with maximum sound and operating reliability The amplifier stage consists of a 2x 2 kW amplifier in Class G design supplied from a conventional power supply with a torodial transformer and a massive 400 Joule capacitor bank with a large dynamic reserve for sustained high power output even in two ohm loads In order to maintain strict quality standards all Alcons products are burned in and thoroughly tested before shipping The proven combination of advanced2. Damping factor Stereo power 1 kHz 0 5 THD Bridged mono power 1 kHz 0 5 THD Mains supply voltage Current draw Weight Housing Dimensions Uu ALC4 User s Manual Rev 0 040 2 Vrms 8 dBu 21 dBu 20 kOhm balanced 1 kHz gt 55 dB 250 W 8 10 Hz 20kHz 0 1 dB 10 Hz 50 kHz 3 dB 32 dB 40x 1 kHz gt 75 dB 20 kHz gt 50 dB 1 kHz 250W 8 lt 0 007 20 kHz 250 W 8 lt 0 2 2 kHz 10 kHz 8 O lt 0 04 gt 111 dB A wght lt 70 dBu A wght 80 gt 40 V us 1 kHz 80 gt 10 000 1 8 RMS Peak 1150 W 1270 W 4 Q RMS Peak 1720 W 1960 W 2 RMS Peak 2250 W 2760 W 16 O RMS Peak 2300 W 2540 W 8 RMS Peak 3440 W 3920 W 4 RMS Peak 4500 W 5520 W 120 or 230 VAC 50 60 Hz factory configured stated at rear of amplifier idle At power up 230 VAC lt 40A 100 VA 1 8 of full power into 2 2200 VA 33 5 kg 73 Ib 19 inch rack mount 3 HU 457 18 inch deep behind the mounting surface 132x482x500 5 2x19x19 7 inch hxwxd including rack handles 27 11 Block diagram SIGNAL UMT INDICATION INDICATION are INDICATION INDICATION Y RF CLIP DC MONITOR MONITOR MONITOR 2 CHANNEL1 BALANCED INPUT POWER 3 AMPLIFIER O Dc OUTPUT BLOCKING RELA
3. Retain this documentation for future reference Always operate the amplifier with a grounded AC mains supply Ensure that the quality of the mains supply is good enough and that it can supply the required peak currents In addition proper earthing is necessary to prevent hum and safety problems Do not use the amplifier if there is visual damage to the enclosure or cables Inspect the amplifier and wiring before use When in doubt have the amplifier inspected by authorized technical personnel Do not make connections to the amplifier while it is switched on Always shut off the amplifier wnen making connections to it and mute the inputs when making connections to preceding equipment in the chain Do not spill water or any other liquid to or into the amplifier Do not operate the amplifier if suspected or standing in liquid Do not block the air intake for the fan on the front or the exhaust ports on the left side of the amplifier The amplifier can run hot or even go into protect mode if there is insufficient cooling air Do not remove the cover There are no user serviceable parts inside the amplifier Removing the cover exposes you to dangerous voltages inside the amplifier Refer servicing to qualified service personnel Servicing is required when the amplifier has been damaged in any way liquid has been spilled on or into the amplifier does not operate normally or has been dropped Do not series or parallel connect an
4. The output sections of the ALC4 have a current limiter protecting the output devices from loads lower than two ohms or short circuits Current limiting is dynamic which means that the amplifier does not shut down but dynamically limits its current but keeps working Ground lift switch If hum is audible the cause may be a ground loop in your sound system The ground lift switch lifts the ground from your sound system from the AC mains ground thus opening the ground loop A ALC4 User s Manual Rev 0 5 2 Important safety instructions Warning To reduce the risk of fire or electric shock do not expose this apparatus to rain or moisture Read these instructions Keep these instructions Heed all warnings Follow all instructions Do not use this apparatus near water Clean only with dry cloth Do not block any ventilation openings Install in accordance with the manufacturer s instructions Do not install near any heat sources such as radiators heat registers stoves or other apparatus that produce heat Do not defeat the safety purpose of the polarized or grounding type plug A polarized plug has two blades with one wider than the other A grounding type plug has two blades and a third grounding prong The wide blade or the third prong are provided for your safety If the provided plug does not fit into your outlet consult an electrician for replacement of the obsolete outlet Protect th
5. amplifier output with any other amplifier output Connecting outputs together can cause damage to the amplifiers A ALC4 User s Manual Rev 0 7 4 Installation Unpacking Carefully open the shipping carton and inspect the amplifier Every Alcons amplifier is thoroughly tested and inspected before leaving the factory and should arrive in perfect condition If you find any damage notify the shipping company immediately Only you the consignee may initiate a claim for shipping damage Be sure to save all packing materials for the carrier s inspection Please save the packing material If you ever need to ship the amplifier back to your dealer or the factory you should only use the original packing Mounting The ALC amplifiers mount in standard 19 inch racks Rear mounting ears give additional support Rear support is highly recommended in all mobile and touring systems ALC4s may be stacked directly on top of each other There is no need for spacing between units O 026 Height 5 2 132mm Sec lt q Front width 19 482mm gt 43mm Depth 18 457mm Rear width 17 1 435mm A A e esea em dun ts sages dn keno eris tos whee desta as pas lt M ALC4 User s Manual Rev 0 8 4 Installation Cooling and ventila
6. input When a large amount of RF is detected on the input signal the related channel is muted Removing the signal will automatically reset this condition 2 DC on the output When DC is detected on the output the output relay will open to protect the loudspeakers from DC Usually this indicates a defect in the amplifier and the need for servicing 3 High temperature When it is flashing the output section of the related channel is between 85 and 90 degrees centigrade 185 194 F and the ALC4 has shut down its class G stage The amplifier will continue working but at lower power When it is constantly illuminated the temperature is above 90 degrees centigrade 194 F and the input of that channel is muted until the temperature has dropped to a safe value When the amplifier is in thermal protect mode the fan is running at full speed The protect LEDs will also illuminate during power up of the amplifier to indicate power up muting of the amps When you have installed SDP protection modules these yellow LEDs indicate power or excursion protection limiting of the modules Flashing of these LEDs is normal however the action of the SDP limiters can become audible if the amount of overdrive is too much A ALC4 User s Manual Rev 0 21 7 Operation Inputs in parallel mode switch The parallel switch behind the cover on the front panel toggles the amplifier between stereo and parallel mode Use parallel mode when you want to drive both channels
7. of the cable length A ALC4 User s Manual Rev 0 4 1 Introduction ATCM Advanced Thermal and Clip Management ATCM has a number of sensors within the amplifier that constantly monitor both operating temperature in and output signal For the temperature section of ATCM the class G stage is regulated when dangerous temperature increase is sensed In this way the amplifier stays in operation instead of switching into heat protection The clip limiter section reduces the signal input level to the safest maximum level when continuous clipping is detected In this way your high frequency drivers are protected against damage from harmonics and also the amplifier remains cooler Variable speed DC fan Heat sink and power supply sensing circuits control the intelligent variable speed DC fan Fan speed increases only as required by the measured temperatures thus keeping fan noises to a minimum RF and ultrasonic protection ARF sensing circuit is continuously monitoring the inputs of the ALC4 to detect ultrasonic energy When RF energy is detected the inputs of the ALC4 are muted to prevent damaging your loudspeakers or the amplifier DC and subsonic protection The ALC4 senses DC and very large subsonic waveforms at both amplifier outputs When DC or subsonic energy is detected the corresponding output relay will be opened to protect any connected loudspeakers and the related protect LED will illuminate Short circuit protection
8. the output and sense wires are connected together at the loudspeaker terminal All Alcons loudspeaker cabinets are SIS pre wired If your loudspeakers are not prepared for SIS wiring you can connect the sense wires to the output wires at the loudspeaker input If you do not want to use the SIS feature at all the sense wires should be connected to the output wires at the amplifier output in the Speakon connector WARNING Never connect the sense to the output terminal or vice versa or short circuit both sense wires Since you are disabling the amplifier s feedback network the amplifier can produce a large amount of DC at its output This will severely damage your amplifier or loudspeakers As ALC4 User s Manual Rev 0 14 6 Connections The Speakon connector is wired as follows Speakon male plug viewed from the wiring side 1 Output 1 Output 2 Sense 2 Sense Connection without SIS Normal loudspeaker connection A ALC4 User s Manual Rev 0 1 5 6 Connections For a given loudspeaker impedance the proportional power loss as a function of cable length and cable gauge is given in the next table 8O 40 20 1 5 2 5 4 6 1 5 mm 2 5 4 6 1 5 mm 2 5 4 6 5 meters 14 0 8 0 5 0 4 2 8 90 1 7 1 1 0 7 54 3 3 96 2 1 96 1 4 96 10 meters 2 8 1 7 96 1 1 96 0 7 96 54 3 3 96 2
9. 1 96 1 4 96 10 2 96 6 4 96 4 1 96 2 8 96 15 meters 4 1 96 2 5 96 1 6 96 1 1 96 7 8 96 4 9 96 3 1 96 2 1 96 14 5 96 9 3 96 6 0 4 1 96 20 meters 5 4 96 3 3 96 2 1 96 1 4 96 10 2 96 6 4 96 4 1 96 2 8 96 18 5 96 12 0 96 7 8 96 5 4 96 25 meters 6 6 96 4 1 96 2 6 96 1 7 96 12 4 96 7 8 5 0 96 3 4 96 22 1 96 14 5 96 9 6 6 6 30 meters 7 8 4 9 3 1 2 1 14 5 9 3 6 0 4 1 25 4 96 16 4 96 11 3 96 7 8 96 40 meters 10 2 96 6 4 96 4 1 96 2 8 96 18 5 96 12 0 96 7 8 96 5 4 96 31 2 96 21 4 96 14 5 96 10 2 96 50 meters 12 4 7 8 96 5 0 96 3 4 96 22 1 96 14 5 96 9 6 96 6 6 96 36 2 96 25 4 96 17 5 96 12 4 96 To calculate the SPL losses from these percentages in dB s the following equation may be used dB loss 20 log 1 1055 100 In the next table a few percentages are converted to dBs 96 loss dB loss 1 96 0 1 dB 2 96 0 2 dB 5 0 4 dB 10 96 0 9 dB 15 96 1 4 dB 20 1 9 dB 25 96 2 5 dB 30 3 1 dB 35 3 7 dB 4 ALC4 User s Manual Rev 0 16 6 Connections Stereo mode E d N prevent fre or elacirio shook TE or BUT To reduce the riek electric shook do not remove the cover usar not expose this equipment to rain or moleiure sarviosebia paris Inelde Refer servicing to queiitied service personnel AVERTISSEMENT ATTENTION Pour viisc le de choc lectrique ou d inosndis ATTENTION Pour viter les ris
10. Y CHANNEL 1 OUTPUTS SIGNAL LIMIT PROTECT CLIP INDICATION INDICATION INDICATION INDICATION RF CLIP v MONITOR Y v MONITOR MONITOR 2 CHANNEL2 BALANCED INPUT PARALLEL MODE MUTING POWER SWITCH AMPLIFIER 3 OUTPUT be RELAY BRIDGE MODE BLOCKING CHANNEL2 OUTPUTS ans 4 User s Manual Rev 0 28
11. been damaged because of any misuse accident or negligence Warranty also does not extend to a new Alcons product if the serial number has been defaced altered or removed What we will do Alcons Audio BV will replace defective parts and repair malfunctioning products regardless of the reason for failure except as excluded Warranty work can only be performed at our authorized service centres or at our factory Disclaimer Alcons Audio BV is not liable for any damage to loudspeakers amplifiers or any other equipment that is caused by negligence misuse or improper installation of the ALC amplifiers Alcons Audio BV is not liable for any incidental damages resulting from any defect in the new Alcons product This includes any damage to another product or products resulting from such a defect Alcons Audio BV reserves the right to change specifications without notice A ALC4 User s Manual Rev 0 25 9 Service and support Contact information Mailing address Alcons Audio BV De Corantijn 69 1689 AN ZWAAG The Netherlands Telephone Facsimile Telephone 31 0 229 283090 Fax 31 0 229 283099 World Wide Web http www alconsaudio com E mail info alconsaudio com M ALC4 User s Manual Rev 0 26 10 Specifications Input sensitivity for max RMS power Maximum input level Input impedance Input CMRR Frequency response Gain Channel separation THD N SMPTE IMD S N ratio Noise floor Slew rate
12. cated in 2 front accessible slots the characteristics of the connected speaker are loaded into the amplifier With this the amplifier is tailor made to the speaker regardless of the power output specifications of the amplifier Multiple processing functions are operating at the same time protection The speaker is protected against damage from over excursion and power overload dedicated filtering The fixed cross over settings cater for the best system performance optimised power response The SDP module adjusts the RMS and peak values to the speakers capacity giving maximum system power output system equalising This circuit equalises the system response with utilising the maximum component efficiency This results in higher overall system sensitivity and reduces the need for active filtering while offering efficient amplifier usage passive system High efficient Class G power stages The ALC4 is equipped with two class G power amplifiers for increased thermal efficiency while also saving weight on the heat sinks and the power supply SIS Signal Integrity Sensing SIS is a unique feature installed in all Alcons amplifiers that senses the signals arriving at the loudspeaker terminals and so compensating for errors introduced by cable resistance and self induction Doing so SIS maintains low linear and non linear distortion compensation of signal loss and high damping figures thus achieving high signal integrity regardless
13. design quality construction and active protection circuits is your guarantee of fail safe reliability and many years of trouble free operation while enjoying the excellent specifications You can depend on consistent stable performance even in the most demanding fixed or mobile sound reinforcement applications Speakon and PowerCon are trademarks of Neutrik amp AG ALC4 features Dual Power Supply The ALC4 is equipped with separate power supplies for both channels Balanced input stages Balanced XLR inputs make the amplifier less susceptible to noise and AC hum pickup especially when using long cable runs Signal link outputs The XLR link output connectors are internally hardwired to the input connectors and can be used to daisy chain the input signals to another amplifier Dual output connectors Each channel of the ALC4 is equipped with two four pole Speakon outputs for easy installation A ALC4 User s Manual Rev 0 1 Introduction Inputs in parallel mode Inputs in parallel mode can be used if you want to drive both channels with one signal without the need for link or Y cables Bridged mono mode Bridged mono mode combines the output power of the two amplifier channels into one loudspeaker load resulting in twice the voltage swing and four times the power in a specific load SDP Speaker Drive Processor The SDP circuit can be seen as the brain of the amplifier By means of speaker specific modules that are lo
14. e clip limiter cannot be switched off RF protection sensing circuit is continuously monitoring the inputs of the ALC4 to detect ultrasonic energy When RF energy is detected the inputs of the ALC4 are muted to prevent damaging your loudspeakers or the amplifier Temperature protection The ALC4 is cooled by a large 120 mm 4 7 in variable speed fan located behind the grill on the front panel Fan speed increases only as required by measured temperatures keeping fan noise to a minimum Under extreme thermal load the fan will force a very large volume of air through the heat sinks If either one of the heat sinks or the toroidal power transformers surpasses the maximum allowed temperature the ALC4 temperature protection circuits become active When the output section of a channel reaches 85 degrees centigrade 185 F the ALC4 shuts down its class G stage To indicate this the protect LED is flashing This is usually sufficient to prevent the amplifier from shutting down completely When the protect LED is constantly illuminated the temperature is above 90 degrees centigrade 194 F and the input of that channel is muted until the temperature has dropped to a safe value DC protection The ALC4 senses DC and very large subsonic waveforms at both amplifier outputs When DC or subsonic energy is detected the corresponding output relay will be opened to protect any connected loudspeakers and the related protect LED will illuminate S
15. e power cord from being walked on or pinched particularly at plugs convenience receptacles and the point where they exit from the apparatus Only use attachments accessories specified by the manufacturer Use only with the cart stand tripod bracket or table specified by the manufacturer or sold with the apparatus When a cart is used use caution when moving the cart apparatus combination to avoid injury from tip over Unplug this apparatus during lightning storms or when unused for long periods of time Refer all servicing to qualified service personnel Servicing is required when the apparatus has been damaged in any way such as the power supply cord or plug is damaged liquid has been spilled or objects have fallen into the apparatus the apparatus has been exposed to rain or moisture does not operate normally or has been dropped A The lightning flash with arrowhead symbol within a triangle is intended to alert the user to the presence of uninsulated dangerous voltage within the enclosure that may be a risk of electric shock to humans A The exclamation point within a triangle is intended to alert the user to the presence of important operating instructions in the literature accompanying the product alcons ALC4 User s Manual Rev 0 6 3 Precautions Save the packing material Should you ever need to ship the amplifier use only the original packing Read this manual carefully before installing and operating your amplifier
16. ed All SDP modules can be used in normal mode or in bridge mode The ALC4 automatically recalculates the limit thresholds to compensate for the extra gain of the amplifier Once the modules are installed put the cover back on Installing the SDP module cards A ALC4 User s Manual Rev 0 1 0 5 Overview Front panel 1 3 7 8 9 0 17 42 13 14 1 Power LED Blue power indicators indicate that the amplifier is switched on 2 Signal LED A yellow LED illuminates when signal is present on the amplifier s inputs independent of the gain settings 3 Clip LED A red LED flashes when the amplifier reaches its maximum output voltage Continuous clipping will trigger the amplifiers active clip limiter circuits 4 Protect LED These LEDs indicate a number of fault conditions Flashing indicates high internal temperatures and level limiting of the input signal When these LEDs are constantly illuminated the amplifier is in protect mode and the signal to the amplifier is muted This indicates either High temperatures in the amplifier s output section or power supply RF on the input DC on the output These LEDs also illuminate during power up M ALC4 User s Manual Rev 0 11 5 Overview 5 Gain CH1 bridge This control adjusts the amplifier s gain for channel 1 or the entire amplifier in mono bridge mode operation 6 Gain CH2 This control adjusts the ampl
17. hort circuit protection The ALC4 output section features a dynamic current sensing and limiting circuit When the currents sourced or sinked by the output section exceed the programmed limits the dynamic current limiter starts conducting drive current away from the output transistors and thus limiting output current This circuit prevents the output devices from very low lt 2 Q impedances or short circuits A ALC4 User s Manual Rev 0 23 8 Safety AC inrush limiter The AC inrush limiter is active when the ALC4 is switched on The AC mains inrush current is limited to a safe value The second power supply is switched on with a two second delay However take care not to switch on too many amplifiers at the same time or you may risk that the main fuses of your AC distribution will blow M ALC4 User s Manual Rev 0 24 9 Service and support Warranty Summary Alcons Audio BV warrants the original purchaser and any subsequent owner of each new Alcons product for a period of three years from the date of the original purchase by the original purchaser that the new Alcons product is free of defects in materials and workmanship Alcons Audio BV warrants the new Alcons product regardless of the reason for failure except as excluded in this warranty In order to obtain warranty you must keep the original sales receipt to establish the exact date of purchase Items excluded from warranty Warranty does not cover any product which has
18. ifier is in parallel input or bridged mono mode this connector is the input for both channels This three pole male XLR connector is internally hardwired to the channel 1 input connector You can use this connector to daisy chain the channel one input signal to the next amplifier 13 6 Connections Inputs The ALC4 has female XLR connectors for the signal inputs and male XLR connectors for the input links These connectors are wired with pin 2 hot XLR connectors viewed the rear of the amplifier 1 Ground 2 Signal 3 Signal The link connectors are internally hardwired to the input connectors and can be used to daisy chain the input signals to another amplifier If you want to drive the amplifier from an unbalanced source preferably connect pin 3 to pin 1 in the source connector If this is not possible connect pin 3 to pin 1 at the amplifier s connector Remember that balanced connections are less susceptible to AC hum however unbalanced signals can be used for short cable runs Outputs Loudspeakers are connected using Speakon connectors For each channel two Speakon connectors are available which are connected in parallel Due to the SIS Signal Integrity Sensing feature on the ALC4 there are four connections per channel instead of two The two extra wires are used for voltage sensing at the loudspeaker terminals The output and sense wires are connected together at the loudspeaker terminal and
19. ifier s gain for channel 2 7 SDP slot CH1 bridge Insert SDP modules for channel 1 or bridge mode operation in this connector 8 SDP slot CH2 Insert SDP modules for channel 2 in this connector 9 Parallel mode switch When this switch is set to the right hand or ON position the signal on the channel 1 input connector is also fed to the channel 2 input circuitry In this mode each channel uses its own SDP module and gain control 10 Bridge mode switch When this switch is set to the right hand or ON position the amplifier operates in bridge mode 11 SDP limit CH1 This LED indicates limiting of the channel 1 SDP module 12 SDP limit CH2 This LED indicates limiting of the channel 2 SDP module 13 Air inlet grill Cooling air inlet grill Make sure this inlet remains clear to allow unrestricted air intake 14 AC power switch This control switches the mains supply for the amplifier on or off Rear panel CAUTION ONTON a provoni wa erence ME A To reduce the of electric shock do not remove the cover No user not expose this equipment to rain or moisture DO MOT OPER eerviosable parte Inside Refer servicing to quaiivied asrvios personnel comports aucuns pl os pouvant Sire Oster tni ee teaches qe am AVERTISSEMENT ATTENTION Pour le rleque de choo lsc rique ou d inosndis ATTENTION m Wenpoesz 5 ni eux projections QC dn PUTS ad
20. n above Connect your signal source to the channel 1 input In this mode only the channel 1 SDP module can be used The channel 1 gain control sets the gain for the entire amplifier Remember that in bridge mode the amplifier cannot cope with loads lower than 4 M ALC4 User s Manual Rev 0 1 9 6 Connections Data port The Data port located on the rear panel of the ALC4 is the connection for remote controlling the amplifier Through the 15 pin high density D connector signals indicating the status of the ALC4 are available for the remote control unit The input signals to the amplifier can also be supplied through this connector For cinema applications the Data port is compatible with existing D connector connected cinema monitors In that application in addition to the data port connection only the AC mains and loudspeakers need to be connected and so the Data port caters for reduced set up and installation time and standardised in and output levels Data port pinout alcons Channel 1 audio input Not used Channel 1 voltage monitor plus parallel bridge mode information Channel 1 current monitor plus channel 1 temperature information Channel 1 clip and protect information Ground Channel 1 audio input Channel 2 audio input 15V output max 200 mA Reference ground Channel 2 audio input Model ID Channel 2 voltage monitor plus power supply monitor Channel 2 current monitor plus chan
21. nel 2 temperature information Channel 2 clip and protect information ALC4 User s Manual Rev 0 20 7 Operation Power On Off switch This control switches the mains AC power of the amplifier Gain controls Two gain controls adjust level for their respective channels The controls are calibrated in dB s gain for the entire amplifier In bridged mono mode the channel 1 control controls the signal level Remember that in bridged mono mode the voltage gain of the amplifier is multiplied by two so you must add 6 dB to the control scale Indicators Each channel of the ALCA is equipped with five LED indicators Power Signal Clip Protect SDP Limit These blue LEDs will illuminate when the amplifier is switched on These yellow LEDs will illuminate when an input level of more than 40 dBu is present at the input of that channel The signal LEDs work independently of the setting of the input gain controls The red clip LEDs will illuminate when the output of that channel has reached its maximum output voltage The indication works for both positive and negative peaks of the signal and is correct for every connected impedance When the signal is distorted more than 0 5 due to clipping the clip limiter quickly reduces the gain to minimize the amount of overdrive When a clip LED is flashing it is recommended to decrease the signal level to the amplifier The red protect LEDs indicate a number of conditions 1 RF on the
22. ques de choc lecivique ne pas enlever le axosesive ni eux projections PARALLEL MODE i Signal channel 1 Signal channel 2 BRIDGE MODE For stereo mode set both DIP switches behind the cover on the front panel to the left hand position In stereo mode connect your loudspeakers with or without SIS to the channel 1 and channel 2 outputs and your signals to the channel 1 and channel 2 inputs In this mode each channel can have its own SDP module and uses its own gain control M ALC4 User s Manual Rev 0 17 6 Connections Inputs in parallel mode CAUTION CAUTION WEGE NS urement diti RS OF ELECTRO SHOCK To reduce the of electric shook do not remove the cover No uaar not expose this equipment to rain or moleiure esrviosabis peris inside Refer servicing to qualified esrvios personnel AVERTISSEMENT ATTENTION Pour viter rieque de ohoc leciriqus ou Pour viter les rieques de choc lectrique ne pas enlever le ni eux projections PARALLEL MODE c Signal BRIDGE MODE For inputs in parallel mode set the upper DIP switch behind the cover on the front panel to the right hand or ON position Use parallel mode when you want to dri
23. r matches that of the amplifier Connecting the ALC4 to the wrong voltage is dangerous and may damage the amplifier For safety reasons you also must ensure that the AC supply is properly grounded The AC current draw is measured according to the IEC 65 safety standard The normal operating power is measured using pink noise with an average power equal to 1 8 of full power This corresponds to normal music being played to the clip level of the amplifier The table below shows the AC current draw for different loudspeaker loads Make sure your AC power distribution can handle the currents demanded by the amplifiers Peak output power per channel AC power draw Idle 80 1270W 1000 VA 100 VA 40 1960 1400 100 20 2760 2200 100 The AC mains power may not deviate more than 10 from the nominal value alcons ALC4 User s Manual Rev 0 4 Installation Installation of SDP module cards If you are using SDP Speaker Drive Processor modules you can install them behind the cover on the front panel To do this switch off the amplifier and unscrew the cover on the front panel Place the SDP modules with the component side up in the SDP connectors The upper connector is for channel 1 or mono bridge mode operation the lower one is for channel 2 The modules lock into position and do not need to be secured The ALC4 automatically routes the signals through the modules once they have been insert
24. rule 4 ALC4 User s Manual Rev 0 12 5 Overview 1 Outputs CH2 2 Outputs CH1 3 Mains fuses 4 AC power input 5 Ground lift switch 6 Data port 7 Link CH2 output 8 2 input 9 CH1 input 10 Link CH1 output M ALC4 User s Manual Rev 0 Two four pole Speakon connectors are installed to connect your loudspeakers to the channel 2 amplifier Two four pole Speakon connectors are installed to connect your loudspeakers to the channel 1 amplifier These are the primary fuses for the power supply Replace these fuses only after disconnecting the mains power cord Replace only with fuses of the same type and rating Connect the supplied AC mains cable to this connector Make sure your mains supply matches the specifications stated on the label next to this connector This switch can be used to lift the amplifier s ground from the mains ground If there is any hum audible this switch may interrupt a ground loop and solve your problem Through this 15 pin high density D connector a remote control processor or cinema booth monitor can be connected This three pole male XLR connector is internally hardwired to the channel 2 input connector You can use this connector to daisy chain the channel two input signal to the next amplifier Connect your signal source for channel 2 to this three pole female XLR connector Connect your signal source for channel 1 to this three pole female XLR connector When the ampl
25. tion The ALC4 amplifier uses forced air cooling in order to maintain a low operating temperature In the ALC4 the cooling air enters at the front and the hot air leaves the amplifier at the left and right side The reason for this is that the air outside the rack is usually cooler than inside and therefore the amplifiers can run at higher continuous power levels without thermal problems Should the amplifier get too hot the related channel will be protected When the output devices of the amplifier reach a temperature of 85 degrees centigrade 185 F the ALC4 will prevent further temperature rise by shutting down the class G amplifier stages This is indicated by the protect LED blinking Usually this will reduce the amount of heat produced in the amplifier enough to stop it from overheating If this is not the case when the amplifier reaches 90 degrees centigrade 194 F the related channel will be muted and the protect LED will be illuminated constantly When the amplifier cools down to a safe value normal operation is resumed Make sure that there is an adequate supply of fresh air in front of the amplifier and that there is sufficient space in the rack for the exhaust to escape In order to let the warm air leave the rack unobstructed the rack must have openings in it of at least 150 cm per ALC4 Mains Power The AC mains voltage for the ALC4 amplifier is stated at the rear of the amplifier near the PowerCon input Make sure your local powe
26. ve both channels with one signal while keeping separate control of both channels SDP processing and gain In parallel mode connect your loudspeakers with or without SIS to the channel 1 and channel 2 outputs and your signal source to the channel 1 input In this mode each channel can have its own SDP module and uses its own gain control M ALC4 User s Manual Rev 0 1 8 6 Connections Bridged mono mode mn CAUTION A prevent fire or RISK OF ELECTRIC SHOCK To the of shook do not the not expose this equipment to rain or moleiure DO OPEN esrvioseble paris Inside Refer servicing to qualified service personnel AVERTISSEMENT ATTENTION Pour le rleque de choc isoiriqus ou d inosndis Pour viter les rleques de choc lectrique pee enlever le Wexposez couvercle Cet apperell ne comporis aucune pi os pouvant sre projections par fuilllleateur Confler Fenirsiien un technioien qualii 120VAC MA 50 80 Hz 230VAC 12A 50 00 Hz PARALLEL MODE EH BRIDGE Signal MODE For bridged mono mode set the lower DIP switch behind the cover on the front panel to the right hand or ON position Use bridge mode when you want to combine the power of two amplifier channels into one loudspeaker load In bridge mode connect your loudspeaker with or without SIS to the channel 1 and channel 2 outputs as show
27. with one signal while keeping separate control of both channels SDP processing and gain Mono bridge mode switch The bridge mode DIP switch behind the cover on the front panel toggles the amplifier between stereo and mono bridge mode In bridge mode the channel 1 input feeds the entire amplifier Gain is controlled by the channel 1 gain potentiometer In this mode only the channel 1 SDP module can be used You can use standard SDP protection modules in bridge mode The ALC4 automatically recalculates the limit thresholds to compensate for the extra gain of the amplifier Remember that in bridge mode the amplifier cannot cope with loads lower than 4 Q Ground lift switch If hum is audible the cause may be a ground loop in your sound system The ground lift switch lifts the ground from your sound system from the AC mains ground thus opening the ground loop M ALC4 User s Manual Rev 0 22 8 Safety Protection circuits Clip limiter When the output signal is distorted more than 0 5 due to clipping the clip limiter quickly reduces the gain to minimize the amount of overdrive The clip limiter reduces high frequency harmonics caused by clipping It also protects high frequency drivers from excess overdrive and clipping harmonics The clip limiter reduces overdrive peaks allowing a higher average output level without audible distortion Increasing the gain until the limiter becomes audible will degrade your sound quality Th
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