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POWER AMPLIFIER
Owner’s Manual
POWER
350
POWER AMPLIFIER XS SERIES
ON OFF
POWER SIGNAL CLIP PROTECTION CLIP SIGNAL
CH A CH B
E
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Introduction Thank you for purchasing a Yamaha XS350, XS250 series power amplifier. This series of audio amps was developed from Yamaha's wealth of experience in building PA equipment and its tradition of careful attention to every detail of circuit design. These amps feature high power and superb quality together with superior reliability and stability, guarantee- ing the highest possible audio performance. Main features of the XS350, XS250 series • The unit is equipped with two types of inputs
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Precautions • Connect this unit’s power cord only to an AC outlet of • Hold the power cord plug when disconnecting it from the type stated in this Owner’s Manual or as marked an AC outlet. Never pull the cord. A damaged power on the unit. Failure to do so is a fire and electrical cord is a potential fire and electrical shock hazard. shock hazard. • Do not touch the power plug with wet hands. Doing so • Do not allow water to enter this unit or allow the unit is a potential electrical shock hazard
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Controls and Functions Front Panel POWER 1 2 3 4 ON OFF POWER SIGNAL CLIP PROTECTION CLIP SIGNAL CH A CH B 1 POWER switch and indicator 4 PROTECTION indicator This is the main POWER switch. Press to power ON These LED indicators light up to indicate that the the amplifier. Press again to power OFF. The POWER protection circuit is working. The speaker system is indicator lights up when the amplifier is powered ON. disconnected from the amplifier outputs and no sound is output from the speaker
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Rear Panel 1 234 FILTER CHANNEL B CHANNEL A FREQ. FREQ. 90 90 15 15 20 20 50 50 10 10 25 25 125 125 6 6 30 30 3 3 40 40 25 150 25 150 00 0 00 0 Hz Hz –dB –dB CHANNEL B CHANNEL A SPEAKERS LOW CUT LOW CUT MODE B-1 CHANNEL A-1 SUB WOOFER SUB WOOFER BRIDGE 4-8Ω /CHANNEL (STEREO) OFF OFF STEREO PARALLEL B-2 CHANNEL A-2 – + + – 4-8Ω /CHANNEL (STEREO) – + + – INPUT INPUT CHANNEL B CHANNEL A CHANNEL B CHANNEL A (BRIDGE) (–) (+) (PARALLEL) G G (–) (+) 8-16Ω (BRIDGE) 8-16Ω
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4 SPEAKERS terminals 6 GND terminals Two types of speaker output terminals: This is the grounding screw terminal. If hum or noise Binding post (Channel A-1, B-1) and barrier strip occurs, ground (earth) the unit via this jack, or try (Channel A-2, B-2) are available. connecting it to the chassis of the mixer or preamp, These parallel wirings are internally connected and etc. output identical signals simultaneously. The output impedance varies depending on whether you use either or both types of
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Speaker Impedance In STEREO and PARALLEL modes, the minimum load (i.e., speaker) impedance is 4Ω . In BRIDGE mode it is 8Ω . Make sure that the impedance does not fall below this specified impedance. Using the barrier strip and binding posts simultanuously MODE SPEAKERS BRIDGE STEREO mode connections: STEREO PARALLEL – + + – – + + – Set to STEREO MODE BRIDGE PARALLEL mode connections: STEREO PARALLEL –– ++ –– ++ Set to PARALLEL Each speaker Each speaker min. 8Ω min. 8Ω MODE SPEAKERS BRIDGE BRI
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Using the barrier strip or terminal posts MODE BRIDGE STEREO mode connections: STEREO PARALLEL Set to STEREO MODE BRIDGE PARALLEL mode connections: STEREO PARALLEL Set to PARALLEL • Using the barrier strip • Using the terminal posts SPEAKERS SPEAKERS – + + – – + + – – + + – – + + – Not used Not used –– ++ –– ++ Each speaker Each speaker min. 4Ω min. 4Ω MODE BRIDGE mode connections: BRIDGE STEREO PARALLEL Set to BRIDGE • Using the barrier strip • Using the terminal posts SPEAKERS SPEAKERS – + + –
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Caution for Speaker Connection 1. Turn off the POWER switch. • Speaker fuse The output capacity of your amplifier is very high: 2. Remove the cover attachment screws and remove the 170 W+170 W (8Ω ), 250 W+250 W (4Ω ) in stereo protective cover from the speaker terminals. and 500 W (8Ω ) in monaural on the XS250; 230 W+230 W (8Ω ), 350 W+350 W (4Ω ) in stereo and 700 W (8Ω ) in monaural on the XS350. Be sure to use a speaker system that has sufficient Screw input capacity. If the input capacity
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Rack Mounting Mounting in an EIA standard rack If multiple high-power amp units are mounted in a rack with poor ventilation, the heat from the amps will cause the interior of the amp to become very hot, causing the performance of the amps to be impaired. In particular, when mounting in a rack whose back can not be left open, mount according to the following instructions. Rack: Leave a gap of 10 cm or more between the rear panel of the rack and the rear panel of the amplifier. 3 Fan: Use a fan
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Portable Rack Mounting This unit uses a forced cooling system in which air comes in through the front opening and goes out from the sides and rear. If you mount a single unit on a portable rack, be sure to maintain vent openings on the rear and sides. (Side View) (Rear View) Completely open Front FILTER CHANNEL B CHANNEL A LOW CUT LOW CUT 40Hz 40Hz 20 15 20 15 OFF 80Hz OFF 80Hz 10 10 25 6 25 6 30 3 30 3 40 40 00 –dB 0 00 –dB 0 CHANNEL B CHANNEL A Air intake Air exhaust HIGH CUT HIGH CUT OUTPUT
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Specifications General Specifications XS250 XS350 Power Output Level (Rated Power) 8Ω /STEREO 170 W + 170 W 230 W + 230 W 20 Hz~20 kHz 4Ω /STEREO 250 W + 250 W 350 W + 350 W THD+N= 0.1% 8Ω /BRIDGE 500 W 700 W 1 kHz 8Ω /STEREO 185 W + 185 W 250 W + 250 W THD+N= 0.1% 4Ω /STEREO 280 W + 280 W 400 W + 400 W 8Ω /BRIDGE 560 W 800 W 1 kHz, 20 ms, no clip 2Ω /STEREO 400 W + 400 W 600 W + 600 W Power Bandwidth Half Power 10 Hz~40 kHz (THD+N= 0.1%) Total Harmonic Distortion (THD + N) 4~8Ω /STEREO 0.05%
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Block Diagram HPF CLIP SIGNAL – INPUT A-1 CHANNEL A + + BA LPF (BRIDGE) CHANNEL + – (PARALLEL) CHANNEL A B-1 PROTECTION – + LOW CUT CHANNEL A – SUB WOOFER (BRIDGE) OFF (PARALLEL) G INV Protector SPEAKERS INPUT + HPF – CHANNEL B – G A-2 + + CHANNEL + – LPF INPUT BA B-2 CHANNEL B CHANNEL B – CLIP SIGNAL LOW CUT SUB WOOFER PARALLEL OFF BRIDGE STEREO MODE Dimensions W:480 Unit: mm 13 FREQ FREQ H:132 D:319
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Troubleshooting The following table lists the main causes of abnormal operation and the corrective measures required, as well as the protective circuit operation in each case. Indicator Probable Cause Remedy Protection Circuit There is a short at a speaker terminal, Locate and correst the amplifier terminal, or cause of the short. wire. The PC limiter circuit CLIP indicator lights. operates to protect the power transistors. Use a speaker system The amplifier load is with an impedance of excessiv
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YAMAHA CORPORATION V352950 R1 1 IP 16 Pro Audio Division, #18/3 P.O. Box 3, Hamamatsu, 430-8651, Japan NP Printed in Taiwan
