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PROBLEM: 

 DISTORTED SOUND

INDICATION: CLIP LED FLASHING

• If the red 

CLIP 

indicator flashes before all three signal indicators do, the load impedance is abnormally low or

shorted. Unplug each speaker one-by-one 

at the amplifier. If the 

CLIP 

LED goes out when you disconnect a

cable, that cable or speaker is shorted. Try another cable and speaker to locate the fault.

INDICATION: CLIP INDICATOR NOT FLASHING

• This could be caused by a faulty speaker or loose connection. Check the wiring and try another speaker.

• The signal source may be clipping. Keep the amplifier gain controls at least halfway up so that the source does

not have to be overdriven.

PROBLEM: 

 NO CHANNEL SEPARATION

• Check the yellow 

PARALLEL 

or orange

 BRIDGE MONO

 LEDs on the front panel, which indicate the switch settings

on the back of the amplifier. Neither should be lit in dual-channel, bi-amp, or stereo use where different signals go to
each channel. Make sure the "Parallel Input" and "Bridge Mode" switches are 

OFF.

• Make sure other equipment in the signal path, such as mixers, preamps, etc., is set for stereo, not mono.

PROBLEM: 

 CH 1 IS ALL LOW FREQUENCY MATERIAL & CH 2 IS ALL HIGH FREQUENCY MATERIAL

• Check that the 

BI-AMP

 LED on the front panel is not illuminated. If it is, the 

MODE

 switch on the rear panel is in the

BI-AMP

 position. Move the MODE switch to the 2 CH position. This assumes you do not want to be in BI-AMP mode

and that you are operating in a 2 channel mode.

PROBLEM: 

 HISS

• Unplug the amplifier input to confirm that the hiss is coming from the source or a device upstream; erratic or popping

noises indicate an electronic fault in the offending unit.

• To keep the normal noise floor low, operate the primary signal source at full level, without clipping, and avoid boosting

the signal further between the source and the amplifier.

PROBLEM: 

 SQUEALS AND FEEDBACK

• Microphone feedback should be controlled with mixer controls. If noise continues to build up with zero mic gain, there

is a serious fault in the signal processors or cables. Working in succession from the signal source towards the
amplifier, check each device in the signal path by reducing its gain or unplugging it.

PROBLEM: 

 HUM

• The PowerLight

TM 

supply eliminates internal hum fields, but  transformers in other magnetic devices may cause

hum. Move cabling and signal sources to identify "hot spots" in the system; then avoid those spots. Cables with
faulty shielding are a common entry point for hum. Use top quality cabling.

Magnetic field from power supplies in equipment can
induce hum into cabling that is located in the field. If
hum is a problem, try relocating cabling so that is
away from power supplies, transformers and other
magnetic field producing devices.

TROUBLESHOOTING: 

DISTORTION, NO CHANNEL SEPARATION, HUM, HISS, FEEDBACK

27

Содержание PL218A

Страница 1: ...User Manual Manuel de l utilisateur Bedienhandbuch Manual del Usario PL218A PL224A PL230A PL236A PL2A Audio Power Amplifiers with Analog Signal Processing POWERLIGHT 2A TD 000089 00 Rev B TD 000089 00...

Страница 2: ...interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance to the instructions may cause harmful inter...

Страница 3: ...cy Delay and HF ATTEN 11 HORN BOOST 12 POWER LIMITER 13 CLIP LIMITER 15 Crossover Delay SIP Networks 16 DataPort Front Panel LEDs Gain Controls Basic Overview 18 INSTALLATION Rack mounting Mounting Di...

Страница 4: ...0 and 3 of available power The limiters have a gentle limiting knee which preserves a sense of signal dynamics In bi amplified systems a slower attack release time can be used on the low frequency cha...

Страница 5: ...socket J4 3 Subaudio filter push button switches 1 per channel 4 Subaudio filter on indicator LEDs 1 per channel 5 DIP switch for subaudio filter frequency select low frequency delay enable HF attenua...

Страница 6: ...the front panel clearly indicates when the amplifier in configured for PARALLEL input When to use PARALLEL input configuration Use PARALLEL when you need one signal to drive both channels STEREO Each...

Страница 7: ...s full frequency signals no crossover and is independently controlled gain processing output connection BI AMP This puts the amplifier into a crossover mode CH 1 receives the low frequencies and CH 2...

Страница 8: ...the DataPort input signals will not reach the amplifier PRE PROC This setting will insert the DATAPORT signals ahead of the amplifier s signal processor If you are using external processing on the DA...

Страница 9: ...16 dB of headroom for the rest of the signal processing NOTE The GAIN SENSITIVITY SELECT setting does not effect DataPort gain in any mode FEATURES SETUP REAR PANEL SWITCHES GAIN SENSITIVITY SELECT 1...

Страница 10: ...he speaker s limits The OFF position should be used only for subwoofer systems with rated frequency response below 30 hertz or if low frequency filtering is provided by other devices CH1 SUBAUDIO FREQ...

Страница 11: ...efer to the SIP network value selection chart for more information HF ATTEN These switches are active only when the amplifier is in BI AMP mode These four switches section 3 4 5 and 6 of the left most...

Страница 12: ...de These switches work in combination to control the amount of high frequency horn boost The horn boost is adjustable from 0 to 14dB in 2dB steps as measured at 20 kHz Add the values of the selected s...

Страница 13: ...etermine the desired percentage of power and consult the table at right to convert this to the nearest dB setting Then combine switch settings to obtain the desired setting EXAMPLE You want limiting t...

Страница 14: ...to OFF This tracking mode is not often used but is applied to paging environments with high ambient noise levels Limiting on channel 2 will cause limiting to occur on channel 1 Channel 2 is set up fo...

Страница 15: ...eakers Clip limiter switches are at the bottom of each LIMITER ADJUSTMENT DIP switch 1 per channel 15 POWER LIMITER TRACKING continued The high frequency driver requires a lower power threshold and fa...

Страница 16: ...ter choosing the desired values from the selection chart locate the plastic bag containing the SIP networks and locate the desired value DECODING SIP NETWORK RESISTANCE VALUES see note below decoding...

Страница 17: ...install the side cover plate after installing the SIPs Before installing the SIP as shown right ensure that the pins are straight This will ease insertion into the jack and help to avoid damaging the...

Страница 18: ...or which connects to accessory products to enhance your amplifier application The CM16a Amplifier Network Monitor can remotely control and monitor your PL2A amplifier The DSP 3 digital signal processo...

Страница 19: ...rear is important especially for mobile and touring use Rear rack mounting ear kits are an accessory item and are available from QSC s Technical Services Department or from your dealer or distributor...

Страница 20: ...GE AC mains The correct AC line voltage is shown on the serial number label Connecting to the wrong line voltage is dangerous and may damage the amplifier The power cord attaches to the IEC connector...

Страница 21: ...frequency loss in long cables Balanced inputs Use the XLR or the detachable terminal blocks Proper connection for balanced input options are shown at right Unbalanced inputs Connect the unused side o...

Страница 22: ...Monobr ckenbetrieb Mono puente SPEAKER CABLING Always use the largest wire size and shortest length of wire practical for any given installation Larger wire sizes and shorter lengths minimize power lo...

Страница 23: ...from the side then the knurled retaining nut is tightened banana plug inserted into the post Banana plug capability is provided on non European models ONLY Bridged mono Mono pont Monobr ckenbetrieb M...

Страница 24: ...h security panel installed A droite le panneau avant avec plaquette protectrice install e Rechts ein POWERLIGHT 2A Verst rker mit Sicherheitsabdeckung Derecha un amplificador PL2 Acon el panel de segu...

Страница 25: ...LED indicates that the amplifier is operating Half brightness indicates the amp is in its start up sequence or STANDBY mode As the input signal strength increases the green SIGNAL 20dB and amber 10dB...

Страница 26: ...LED is at full brightness yet the signal LEDs indicate no signal check the input Make sure the signal source is operating and try another input cable Connect the source to another channel or amplifie...

Страница 27: ...sition Move the MODE switch to the 2 CH position This assumes you do not want to be in BI AMP mode and that you are operating in a 2 channel mode PROBLEM HISS Unplug the amplifier input to confirm tha...

Страница 28: ...upply provides power to start up the main supply After three seconds a relay bypasses the inrush limiting and full power operation is enabled The audio circuitry mutes for one second to eliminate star...

Страница 29: ...he DataPort for remote monitoring with QSC s CM16a Processor The output circuitry is actively clamped during clipping for smooth and very fast recovery The clamp also feeds a proportional clip limiter...

Страница 30: ...itch INPUT SENSITIVITY V RMS switch position 26dB 1 2Vrms 32dB 26dB 1 2Vrms 32dB 26dB 1 2Vrms 32dB 26dB 1 2Vrms 32dB for rated power into 8 ohms 2 57 1 28 1 28 3 05 1 20 1 53 3 84 1 22 1 93 3 95 1 24...

Страница 31: ...or CH 1 can be used for one or both channels and for bridged mono COOLING all models Continuously variable speed fan back to front air flow provision for optional air filter AMPLIFIER PROTECTION all m...

Страница 32: ...ift Direcci n postal QSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa CA 92626 1468 USA Telephone Numbers Num ros de t l phone Telefonnummern N meros de tel fono Main Number Num ro principal...

Страница 33: ...______________________ ___________________________ ___________________________ ___________________________ ____________________________ ___________________________ ___________________________ ________...

Страница 34: ...______________________ ___________________________ ___________________________ ___________________________ ____________________________ ___________________________ ___________________________ ________...

Страница 35: ...QSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa California 92626 USA QSC and the QSC logo are registered with the U S Patent and Trademark Office 2000 2007 QSC Audio Products Inc...

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