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16

Audio connections

9.4 Ground loop

control

Strict adherence to the wiring conventions noted above within a fully balanced
signal system will give the best possible results with none of the problems
normally associated with interconnected audio equipment. Wherever possible,
cable screens should not be connected to any signal pin, but rather left to
perform a cable shielding function only.

Where it is not possible to control all of the external cabling, it might become
necessary to have internal electronic ground of your unit separated from the
case safety ground. Provision is made internally within the 

FDS-318

 to separate

these two grounds at a convenient point, and 

reference to section 12.1 

will

explain the procedure.

Under no circumstances should the safety ground wire be removed from the
mains AC power connector as an interim measure to achieve similar results.

Содержание FDS-318

Страница 1: ...1 FDS 318 User Manual...

Страница 2: ...CERTIFICATION VOID For continued compliance with international EMC legislation ensure that all input and output cables are wired with the cable screen connected to Pin 1 of the XLR connectors and or t...

Страница 3: ...wer 13 8 2 Voltage Setting 13 8 3 AC Power Fusing 14 8 4 Powering up 14 9 0 Audio Connections 15 9 1 Wiring convention 15 9 2 Balanced wiring 15 9 3 Unbalanced wiring 15 9 4 Ground loop control 16 10...

Страница 4: ...1 2 Crossover frequency adjustment 25 11 3 Output level alignment 25 11 4 Output MUTE selector 25 11 5 Output polarity reverse selector 25 11 6 Output signal level indicators 26 11 7 CD Horn equalisat...

Страница 5: ...e units work best when they are driven over a limited band of frequencies for example Low Mid and High Any crossover aims to provide the division of the audio band necessary so each drive unit receive...

Страница 6: ...the same job as a passive crossover but with more precision flexibility efficiency and quality Fig 2 1 Active and Passive Crossovers Some advantages of active crossovers are Crossover frequencies can...

Страница 7: ...slopes in excess of 12dB OCT are rarely achieved and power rolloff is 4 times less rapid per octave If one frequency range is driven into clip drive units and horns in other frequency ranges are prot...

Страница 8: ...f frequencies around the crossover point which is where the units from two adjacent frequency ranges are contributing near equal amounts of sound pressure More predictable sound dispersion By providin...

Страница 9: ...e summation and minimal lobing for non coincidental drivers These filters are fully sweepable by accurate front panel controls which are also automatically reconfigured depedant upon the mode of opera...

Страница 10: ...10 Getting to know the FDS 318 Fig 6 1 Front Panel Fig 6 2 Rear Panel...

Страница 11: ...11 All numbers in bubbles refer to Section numbers...

Страница 12: ...ort the unit at the rear and or sides to lessen the stress on the front mounting flange The necessary support can generally be bought ready built as a rack tray As with any low level signal processing...

Страница 13: ...integral moulded 3 pin connector which is provided to satisfy required local standards The FDS 318 must always be connected to a 3 wire grounded earthed AC outlet The rack framework is assumed to be c...

Страница 14: ...voltages when using a 3 phase power connection In either case the transient suppressors can become damaged and constantly blow replacement fuses You can rest assured that your unit has been protected...

Страница 15: ...It is recommended that you use high quality audio cable with 2 cores and a screen for low noise and reliability 9 3 Unbalanced wiring If the equipment driving the FDS 318 has only unbalanced outputs t...

Страница 16: ...rather left to perform a cable shielding function only Where it is not possible to control all of the external cabling it might become necessary to have internal electronic ground of your unit separat...

Страница 17: ...d or divided by 10 for the correct value The control of this is determined by the SELECT MODE switch on the rear panel Individual output control adjustable from 6dB of gain to OFF To ensure adequate r...

Страница 18: ...d system is being driven very hard For a more detailed explanation of this refer to section 11 6 10 6 Select mode LED These LEDs show which mode of operation has been selected by the rear panel SELECT...

Страница 19: ...nd floating Maximum output is 20dBu into 600 ohms or greater Transformer balancing is NOT available as an internally fitted option and so the BSS AR 204 balancing unit should be specified if required...

Страница 20: ...frequency modes 4 way HF Two channels of 3 non overlapping frequency bands with an extra high pass parallel band running at a different selectable frequency This allows a sound system to utilise two...

Страница 21: ...ing frequency bands with the frequency control configured to operate over a 200Hz to 2kHz sweep range 2 way LO Four channels of 2 non overlapping frequency bands with the frequency control configured...

Страница 22: ...mode Use this mode when two high outputs are required such as when an additional long throw driver is needed to augment an existing 3 way system The crossover frequency of the extra output is independ...

Страница 23: ...systems in ancillary areas or act as line drivers with level and mute controls to drive a tape machine recording a show 2 way HI 2 way MID 2 way LO Use these modes for a conventional stereo or multich...

Страница 24: ...24 Fig 11 1 Mode functions...

Страница 25: ...made to balance the system If attenuation greater than dB is required on any individual output you should suspect an imbalance somewhere else in the system and rectify the fault there rather than cont...

Страница 26: ...witch CD EQ will insert a correcting equalisation to all relevant MID and HIGH outputs This is confirmed on the front panel by the appropriate LED The amplifier response of the equalisation is shown i...

Страница 27: ...from the internal chassis connection as an alternative to this procedure Disconnect the mains power cord and remove the units top cover Locate the long green wire positioned at the rear of the unit w...

Страница 28: ...strated by repeated mains fuse failure when powering up the unit Even in this case of extreme overvoltage the unit is protected against failure and the simple removal of these suppressors will allow t...

Страница 29: ...rs Signal overload LED 10dBu at output connectors Modes Stereo 4 way stereo 3 way four channels 2 way Stereo 4 way includes options for extra overlapping high pass and extra overlapping low pass outpu...

Страница 30: ...epaid You should include a statement listing the faults found The unit s serial number must be quoted in all correspondence relating to a claim We recommend that you record your purchase information h...

Страница 31: ...16 I Input connections 19 Installation 12 Invisible slopes 8 L LED rear panel switch 18 select mode 18 Linkwitz Riley 8 M Main power switch 19 Mains fuse 18 Mains power requirements 13 Modes 22 2 way...

Страница 32: ...ty reverse 25 select mode 20 Voltage selector 19 T Transient Suppressor Replacement 28 U Unbalanced wiring 15 Unpacking 9 User Notes 33 V Voltage selector switch 19 Voltage settings 13 W Warranty Info...

Страница 33: ...33 User Notes...

Страница 34: ...34 User Notes...

Страница 35: ...35 User Notes...

Страница 36: ...36 User Notes...

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