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565E Dual Compressor/ Limiter/Expander

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1. All too often paging announcements are either sub audible or distorted The problem is the result of changing input levels from different users Timid Tom vs Sam Screamer and unpredictable environmental circumstances To optimize system levels for intelligibility without overload use the compressor section to even out levels and the peak limiter to put a clamp on Sam Screamer CH1 COMPRESSOR 25 15 12 10 8 6 4 2 oOooo0oo0oo0o0o00 l Q Set the compressor threshold for 6 lt KE Vo R dB of gain reduction with normal paging TA levels SZ a 40 20 FAST SLOW 1 10 Q Set the peak limiter threshold for 6 THRESHOLD dBu RELEASE RATIO X 1 dB of gain reduction when Sam Screamer is on the system Q All normal signals will be slightly compressed and really loud signals will activate the peak limiter With these settings a shy person will be audible and the guy who thinks he has to shout won t be too loud or cause distortion 16 Paging with Ducking Many situations involving a talking host and any sort of musical background will require the background music to drop in level whenever the host signal is present By splitting the host signal part of it can be used to tell the 565E when to take action and lower the background source by an amount determined by the threshold control O CH1 EXPANDER CH1 COMPRESSOR CH1 LIMITER CH1 OUTPUT 0000 00000000 0000 0000 565E 2 1
2. BALANCED PUT OUTPUTS 4 1 4 BALANCED D SIDECHAIN Int SLEEVE GROUND J GROUND J RING LOW SIDECHAIN OUT TIP HIGH KEY INPUT MUSIC KEYBOARD a SN LINE OUTPUT na LIVE KEY MIC INPUT DRUM MACHINE LINE OUTPUT BALANCED KEY IN IGNORE GROUND To use the Key INPUT as a sidechain insert point for external processing of the 565 s sidechain signal connect the Key Input jack s tip and sleeve ground to the input of the external pro cessing device and connect the Key Input jack s ring and sleeve ground to the output of the external processing device In the hookup diagram below an equalizer is shown as an example of an external processing device CHANNEL 2 INPUT CHANNEL 1 OUTPUT SIDECHAIN CHANNI E 5 e ANCED BALANCED na BALANCED BALANCED ALANCED INPUTS UNBALANCED UNBALANCED SLEEVE GROUND GROUND 4j RING LOW SIDECHAIN OUT BALANCED TIP HIGH KEY INPUT BALANCED RETURN Lt SEND CARE GROUND from EQ output SEND to EQ input 15 O Symetrix Applications __Chapter 8 Here are a few applications for which the 565E is an optimal processing tool The following applications make one assumption settings for the threshold control s are a function of each individual system s actual operating level Wherever specific threshold settings are mentioned they are referenced to either a particular ga
3. Compressor Limiter Expander offers two channels of simultaneous in line controls for compression limiting and downward expan sion In addition the 565E employs a new circuitry design Dynamics Squared for dramatically reduced distortion during gain reduction Compression limiting and downward expan sion clear up different but related audio problems Whether you work with vocal tracks stage monitors radio signals paging systems or playback systems it s likely that your audio needs more than one of these solutions The compressor and expander sections of the 565E feature newly developed circuitry Dynamics Squared This proprietary design addresses a key problem most analog com pressors use conventional voltage controlled amplifier topography which creates added distortion when compressing mid band frequencies Dynamics Squared resolves this problem by using circuitry that controls gain while reducing distortion As a result the 565E allows you to apply high levels of compression and expansion with much less distortion If background noise tape hiss or pickup hum is a problem eliminate it with the downward expander The 565E uses a true downward expander not a so called soft gate The 565E s downward expander won t chop off the transients and decays like a gate would yet it can work just as effectively for reducing those noises between sounds While the downward expander quiets un wanted noi
4. The fuseholder accepts 5 x 20mm diameter fuses For 1 17VAC operation the correct value is 0 24 250VAC slow blowing For 230VAC operation the correct valueis 0 1A 250VAC slow blowing Operating Location Do not operate this equip ment under any of the following conditions explosive atmospheres in wet locations in inclement weather improper or unknown AC mains voltage or if improperly fused Do not install near any heat source such as radiators heat registers stoves or other apparatus including amplifiers that produce heat Unplug this apparatus during lightning storms or when unused for long periods of time Stay Out of the Box To avoid personal injury or worse do not remove the product covers or panels Do not operate the product without the covers and panels properly installed Only use accessories specified by the manufacturer Clean only with a damp cloth User serviceable parts There are no user serviceable parts inside the 565E In case of failure refer all servicing to the factory Servicing is required when the 565E has been damaged in any way such as when a 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 Chapter 3 Fast First Time Setup Follow these instructions to get your 565E up and running as quickly as possible The intent of this sectio
5. 40 1 4 45 o COMPRESSOR of sms COMPRE 9 5 rae ra HE e 3 EXPANDER di TE aids FAST SLOW 40 20 FAST SLOW 1 10 2 BYPASS gt 20 O THRESHOLD dBu RELEASE THRESHOLD dBu RELEASE RATIO X 1 THRESHOLD dBu GAIN dB A TO SIDECHAIN FROM AUDIO KEY INPUT OUTPUT PREAMP P TO LINE PAGE PR INPUT MICROPHONE MIC INPUT SPLITTER O Q Set the compressor threshold so that all the gain reduction LEDs for the compressor are illuminated when the host speaks Although the display won t show it you can set the threshold control even lower for more ducking action Q Use the release control to vary the speed at which the music returns when the host stops talking Feedback Elimination in P A Systems and Stage Monitors Public address and sound reinforcement situations that require comp limiting are often plagued by feedback problems The overall increase in level that results from compression can cause feedback in the absence of signal when the compressor releases and brings levels back up to normal CH1 EXPANDER CH1 COMPRESSOR 25 15 12 10 8 6 4 2 00000000 10 BYPASS SLOW THRESHOLD dBu RELEASE FAST SLOW 10 THRESHOLD dBu RELEASE RATIO X 1 Q Set the compressor threshold for no more than 9 dB of gain reduction on normal signals Q Setthe expander threshold for 16 dB or more of gain reduction when the signal source is silent and O dB of gain reduction when
6. LOW FROM BALANCED OUT TERMINAL STRIP HIGH v GROUND FROM UNBALANCED OUT v TERMINAL STRIP H HIG HIGH NOT USED wy GROUND FROM NON TRANSFORMER ELECTRONIC BALANCED OUTPUT TYPICAL OF SYMETRIX PRODUCTS FLOATING BALANCED OUTPUT TO BALANCED IN MALE XLR N Li PIN 3 LOW TO UNBALANCED IN FROM TRANSFORMER COUPLED OR MALE TS PLUG TIP HIGH SE LOW TO BALANCED IN TIP MALE TRS PLUG TIP HIGH ane 7 SLEEVE RING LOW TO BALANCED IN TERMINAL STRIP HIGH LOW wy GROUND TO UNBALANCED IN MALE TS PLUG TIP HIGH LD FEMALE XLR PIN 1 GROUND LOW Es PIN 2 HIGH u PIN 3 NOT USED ee REV B SLEEVE GROUND SLEEVE GROUND LOW PIN 1 GROUND PIN 2 HIGH SLEEVE GROUND us is 13 i Sidechain Key Input Connection The 565E s Sidechain Key INPUT connector is a 1 4 inch TRS jack and is both an input and an output on the same connector This jack is wired Tip return input Ring send output and Sleeve ground This connection can be used as a key trigger input or as a sidechain insert point for external processing When using the KEY INPUT as a trigger input the 565E re
7. The three displays associated with the expander compressor and limiter indicate a parameter called gain reduction Simply stated the gain reduction indication shows how far the gain or amplification was reduced from unity Another way of looking at this is if the gain reduction display says 10 dB of gain reduction switching the unit to bypass will result in a 10 dB increase in the output level The output display indicates output level in dBu For most applications just make certain that you never see the CLIP LED illuminate Using the Sidechain The sidechain is a patch point in the control circuit of a dynamic range processor It provides access to the part of the circuitry that tells the VCA voltage controlled amplifier what to do The 565E s sidechain is routed through a TRS jack labeled KEY INPUT This jack is located on the rear panel and it provides both a send and return via the same jack The sidechain connection affects all three processors in the 565E The 565E s sidechain connections are derived from the balanced input stage and they allow access to the control circuit s input signal The control signal is derived from but kept totally separate from the audio signal path This means that the control signal can be processed outside the 565E without actually processing the signal that s going through the VCA the audio signal itself This presents some very interesting possibilities for changing or improving the ope
8. except that in the real world the device following the expander such as a processor or an amplifier would go into terminal overload The solution is to make soft signals softer a k a downward expansion This is what the 565E s down ward expander does When the signal level falls below the level set by the threshold control the expander reduces its gain by the amount dictated by its expansion ratio Thus for a below threshold signal a 10 dB output change results from a 5 dB change in the input signal if the expansion ratio is 1 2 A gate is similar to an expander except that its ratio is much higher thus the action is more like a switch once the signal falls below threshold Some expander applications for the 565E may be quite similar to a gate like tending a lone announce microphone but downward expanders generally are not well suited to typical gate applications such as removing leakage from drum microphones where very tight control is desired Ratio The compression ratio of the 565E determines how much the output changes for a change in the input A linear amplifier like a simple preamp has a ratio of 1 1 because a change of dB at its input results in a dB change at its output A compressor alters the input output relationship by its compression ratio Thus a 20 1 ratio means that a 20 dB above threshold change at the input results in a 1 dB change at the output In other words a very audible change at the input 20 dB turn
9. jack The balanced inputs shall accommodate 20 dBu signals without distortion and the balanced outputs shall be capable of delivering 22 dBm into a 600 ohm load Overall frequency response shall be 10 Hz to 60 kHz 0 dB 3 dB THD N shall be less than 0 02 measured under the following conditions 4 dBu input 4 dBu output BYPASS switch out 20 Hz to 20 kHz 30 kHz low pass filter 0 dB gain reduction Residual noise output shall be no greater than 90 dBu measured with a 20 kHz noise bandwidth input terminated in 600 ohms Access to each channel s sidechain shall be provided via a single 4 TRS female connector The ring connection shall be the sidechain output and the tip connection shall be the sidechain return The unit shall be capable of operating by means of its own built in power supply connected to 117V nominal AC 105 to 130V 50 60 Hz 230V nominal 207 to253V AC 50 Hz where appli cable The unit shall be a Symetrix Inc model 565E Dual Compressor Limiter Expander Specifications Input Output Limiter Maximum Input Level 20 dBu Balanced Attack Time 100 uS Maximum Output Level 22 dBu Balanced Release Time 100 mS 18 dBu Unbalanced Threshold 12 dBu to 22 dBu Input Impedance 20k Ohms Balanced 10k Ohms Unbalanced Ratio 20 1 Output Impedance 200 Ohms Balanced 100 Ohms Unbalanced Expander CMRR Greater than 40 dB Attack Time 4mS Performance Data Release Time 250 mS to 5 S Frequency Response 10 Hz to 6
10. loading It should be above 600 ohms Is the input of the device following the 565E clipping Is something else clipping Noise hiss Check input signal levels The 565E is intended to operate at or near line level 10 dBu or greater Make sure that the signal you are feeding to the 565E is a line level signal not mic level Check gain settings on downstream equipment The system gain structure should be such that the 565E operates at or near unity gain Is the input signal already noisy No expansion Did you connect the output cable to the Key IN jack instead of the Output jack Is the In Byrass switch set to Bypass Is the In Bypass switch set to IN Check cable connections at Key IN and at the output of any audio source that is being used as a trigger or at the input and output of any external device that is being used to process the sidechain signal i e an EQ Check that any audio source or external device that is connected to the Key IN has power and is turned on Check that any cable that is plugged into the Key IN is also con nected to an audio source or external processing device No LED display Is the unit plugged in and turned on Is the AC outlet OK 19 O Symetrix Specifications _Chapter 10 Architects and Engineers Specifications The Compressor Limiter Expander shall be a dual channel model that controls the dynamic range of wide range wideband audio signals providing compression peak limitin
11. number on the outside of the box 5 Ship the unit to Symetrix freight prepaid We do not accept freight collect shipments Just do these five things and repairs made in warranty will cost you only one way freight charges We ll prepay the return surface freight If you choose to send us your product in some sort of flimsy packaging we ll have to charge you for proper shipping materials If you don t have the factory packaging materials then do yourself a favor by using an oversize carton wrap the unit in a plastic bag and surround it with bubble wrap Pack the box full of Styrofoam peanuts Be sure there is enough clearance in the carton to protect the rack ears you wouldn t believe how many units are returned with bent ears We won t return the unit in anything but Symetrix packaging for which we will have to charge you Of course if the problem turns out to be operator inflicted you ll have to pay for both parts and labor In any event if there are charges for the repair costs you will pay for the return freight All charges will be COD unless you have made other arrangements prepaid Visa or Mastercard Out of warranty repairs If the warranty period has passed you ll be billed for all necessary parts labor packaging materials and freight charges Please remember you must call for an RA number before sending the unit to Symetrix Chapter 12 Declaration of Conformity Declaration of Conformity We Symetrix Inc
12. the threshold level and is usually set by a front panel control The amount by which the compressor lowers the level is the compression ratio and this parameter is usually set via a front panel control as well Compression ratio refers to the ratio of a change at the input versus the change at the output of the device Thus if we apply an above threshold signal that changes 10 dB to the input of a hypothetical compressor and measure a 2 dB change in the output signal that compressor would have a compression ratio of 10 2 or 5 1 reduce the fraction Different compression ratios have different uses Use lower ratios 6 1 or less for level control intermediate ratios 8 1 to 12 1 for leveling making the signal level more or less constant and higher ratios for limiting putting an absolute ceiling on the signal level Limiters are nothing more than compressors but are possessed of much higher compression ratios 20 1 or higher Limiters are typically used to stop occasional peaks which would otherwise cause overload or distortion Typically a limiter is set via its threshold control so that it stays out of the way until a peak comes along Expanders and Gates While a compressor or limiter reduces the dynamic range of a signal by reducing its level once it has exceeded a threshold level an expander does the opposite well almost The easiest way to visualize an expander is to think of it making loud signals louder This is fine
13. 0 kHz 0 3 dB Threshold 10 dBu to 40 dBu true bypass DynamicRange 115 dB difference of max output and noise floor Ratio TAS THD Noise lt 02 4 dBu in 4 dBu out 0 dB gain reduction Connections 20 Hz to 20 kHz 30 kHz low pass filter Input XLR 4 TRS System Gain Control 20 dB center detent Output XLR 4 TRS Output Noise 90 dBu measured at balanced output Sidechain 14 TRS one per channel input terminated in 600 Ohms 20 kHz rolloff in analyzer Polarity pin 2 of XLR is hot tip of TRS jack is hot Crosstalk 95 dB 1k 95 10k 4 dBu in Physical remaining channel terminated in 600 Ohms Size hwd 1 72 x 19x 8 in 4 37 x 48 26 x 20 32 cm 20 kHz rolloff in analyzer Shipping Weight 8 lbs Sidechain 500 Ohms source impedance Electrical 10k Ohms input impedance TRS jack tip is return Power Requirements 120V AC nominal 60 Hz 15 watts Compressor 220V AC nominal 50 Hz 15 watts Type RMS responding Note The maximum operating ambient temperature is Attack Time 2ms 25 degrees C Release Time 180 mS to 2 5 S Threshold 40 dBu to 20 dBu In the interest of continuous product improvement Symetrix Inc Ratio 1 1 to 10 1 reserves the right to alter change or modify these specifications 20 without prior notice 1999 Symetrix Inc All rights reserved Chapter 11 565E Limited Warranty Symetrix Inc expressly warrants that the product will be free from defects in material and workmanship for one 1 year Sym
14. 565E Dual Compressor Limiter Expander User s Guide O Symetrix Table of Contents Chapter 1 Introduction Chapter 2 Operator Safety Summary Chapter 3 Fast Setup Chapter 4 Tutorial Chapter 5 Front Panel Overview Chapter 6 Rear Panel Overview Chapter 7 Connecting to Other Gear Chapter 8 Applications Chapter 9 Troubleshooting Chapter 10 Specifications Chapter 11 Warranty and Service Chapter 12 Declaration of Conformity Rev C 0 10 February 1999 Symetrix part number 53565E0C00 Subject to change without notice 1999 Symetrix Inc All right reserved Symetrix is a registered trademark of Symetrix Inc Mention of third party products is for informational purposes only and constitutes neither an endorsement nor a recommendation Symetrix assumes no responsibility with regard to the performance or use of these products Under copyright laws no part of this manual may be reproduced or transmitted in any form or by any means electronic or mechanical including photo copying scanning recording or by any information storage and retrieval system without permission in writing from Symetrix Inc aon A N 11 16 19 20 21 23 Symetrix 6408 216th St SW Mountlake Terrace WA 98043 USA Tel 425 778 7728 Fax 425 778 7727 Email symetrix symetrixaudio com Chapter 1 Congratulations on your purchase of the Symetrix 565E a one box answer to your dynamics processing needs The 565E Dual
15. AL MONO SWITCH DuaL Mono OUT POSITION CHANNEL 2 REPEAT SETTINGS SHOWN FOR CHANNEL 1 With the 565E s controls and switches now set according to the preceding section the 565E should pass signal Fast setup is complete Refining Your Settings Refine the EXPANDER THRESHOLD setting so that the expander reduces the gain of background noise when the desired input signal is not present but does not reduce the gain when the desired signal is present and does not trigger excessively on short pauses in the program material Adjust the COMPRESSOR THRESHOLD control so that two or three of the compressor gain reduction LEDs light when normal level program material is present Set the LIMITER THRESHOLD control so that the 3 LED just lights on the highest peaks in the audio program material Remember these settings are just guidelines you can use whatever settings work best for you O Symetrix Tutorial Chapter 4 Dynamics Processing Tutorial and 565E Functional Basics Audio signals possess several basic properties amplitude or volume measured in volts or dB frequency or pitch measured in Hertz duration measured in hours minutes seconds and waveform described graphically like sine square triangle or pulse Complex signals like musical sounds are made up of simpler waveforms such as sine waves mixed in the proper proportions Signal processors allow you to manipulate various parameters of an audio signal Equalizers c
16. aries the amount of action higher settings are crisp lower settings merely increase the volume when the kick drum keys the expander Q Use the RELEASE control to make the expander follow the music Sibilance Control Patching an equalizer into the sidechain can cause the 565E to respond more or less to selected frequencies giving it the ability to make sibilance problems less apparent Fine tuning between the compressor threshold ratio and the EQ boost applied in the sidechain will have to be made to arrive at optimum results CHANNEL 2 INPUT CHANNEL 1 OUTPUT SIDECHAIN CHANNI TYPICAL CONNECTIONS BALANOED 2 INPUTS Q To find basic settings start with a fairly high ratio 5 1 or so and a compres sor threshold setting BALANCED between 20 and 5 Cut the GROUND Pr LOW PIN HIGH s PIN NWBALANCED T SIDECHAN TS SLEEVE GROUNO GROUND RING LOW SIDECHAIN OUT TP HIGH s KEY INPUT BALANCED BALANCED OUTPUTS UNBALANCED KEY BALANCED INPUT UNBALANCED O RETURN low frequencies on the SEND equalizer and give a 15 dB CI GROUND broadband boost to the EQ ataround 5 or 6kHz Now carefully tweak the threshold setting as you count four five six What you re looking for is no compression on four five and somewhere around 9 dB of gain reduction on the word six to EQ input Q You can refine the setting by lis
17. d to the Channel 1 controls and the Channel 2 controls have no effect In Dual Mono mode the 565E s two channels operate independently with each Rae channel responding to its own controls Typically the 565E would be switched to DUAL Stereo mode when Channel and Channel 2 are being fed stereo left and right T inputs Set the 565E to Dual Mono mode when Channel 1 and Channel 2 are being STEREO LINK fed signals that you wish to process separately such as a vocal signal being fed to Channel 1 and a bass guitar signal being fed to Channel 2 Duaz Mono LED Indicates that the 565E is switched to Dual Mono mode STEREO LED Indicates that the 565E is switched to Stereo mode O Symetrix Rear Panel Overview Chapter 6 Power Connection Power The power cord plugs into the IEC power receptacle on the rear of the 565E as N Connect the plug end of the power cord to an eael appropriate source of AC power Observe the k ly volt th MAXIMUM ae power supply voltage on the rear CE FABRIQU AUX E U PAR SYMETRIX INC LYNN R F REZ TOUTE R PARATION UN TECHI Audio Output Connections BALANCED UNBALANCED OUTPUT 1 4 inch tip ring sleeve TRS phone jack wired tip high ring low and sleeve ground Use this jack when you need a 1 4 inch balanced or unbalanced output The nominal signal level Trans here is 4 dBu The wiring diagram for the BALANCED UNBALANCED Output connector is reproduced on t
18. e Most dynamics processing equipment has a control marked RELEAsE on the front panel This control refers to release time and it affects the length of time required for the gain to recover to the no signal state when no signal is applied to the input The release time control allows tailoring the expander s or compressor s recovery time to the program material For compressors the no signal state is unity gain passing the signal straight through the compressor with no change in gain Compressors pass any signal whose level is below threshold at unity gain The release time control determines how long it will take for the compressor to return to unity gain once the input signal has fallen below the compression threshold Generally peak limiting is associated with short release times and compression or leveling associated with longer release times For expanders the no signal state is determined by the amount of gain reduction applied when no signal is present at the expander s input The amount of gain reduction is set by the threshold control and by the ratio of the expander and this applies to any signal whose level is below threshold In this case the release time control governs how long it takes for the expander to reduce the gain when the signal disappears Typically smooth expansion of speech or music is associated with longer release times and gating type functions such as feedback suppression are associated with short relea
19. ence or otherwise arising out of con nected with or resulting from the manufac ture sale delivery resale repair replace ment or use of any product will not exceed the price allocable to the product or any part thereof which gives rise to the claim In no event will Symetrix be liable for any inciden Warranty and Service expressly disclaims any IMPLIED warran ties including fitness for a particular purpose or merchantability Symetrix s warranty obligation and buyer s remedies hereunder are SOLELY and exclusively as stated herein This Symetrix product is designed and manufactured for use in professional and studio audio systems and is not intended for other usage With respect to products purchased by consumers for personal family or household use Symetrix expressly disclaims all implied warranties including but not limited to warranties of merchant ability and fitness for a particular purpose This limited warranty with all terms condi tions and disclaimers set forth herein shall extend to the original purchaser and anyone who purchases the product within the specified warranty period Warranty Registration must be completed and mailed to Symetrix within thirty 30 days of the date of purchase Symetrix does not authorize any third party including any dealer or sales representative to assume any liability or make any addi tional warranties or representation regarding this product information on beha
20. entioned impedances The 565E s output impedance is 200 ohms balanced 100 ohms unbalanced The output line driver delivers 22 dBm into 600 ohm balanced loads or 18 dBm into 600 ohm unbalanced loads Polarity Convention The 565E inputs and outputs use the international standard polarity convention of pin 2 hot Therefore if your system uses balanced inputs and outputs and uses the 565E this way then the polarity convention is unimportant If your system is both balanced and unbalanced then you must pay attention to this especially when going in and coming out through different connector types like input on an XLR output on a phone jack XLR 1 4 Phone Signal Pin 1 Sleeve Ground Pin2 Tip High Pin3 Ring Low Input and Output Connections The illustration on the next page shows how to connect the 565E to balanced and unbalanced sources and loads To operate the 565E from unbalanced sources run a 2 conductor shielded cable that s two conductors plus the shield from the source to the 565E At the source connect the low minus side to the shield these connect to the source s ground connect the high plus side to the source s signal connection At the 565E the high plus wire connects to pin 2 the low minus wire connects to pin 3 and the shield always connects to pin 1 This is the preferred method as it makes best use of the 565E s balanced input even though the source is unbalanced The other alternative shown in the
21. etrix s obligations under this warranty will be limited to repairing or replacing at Symetrix s option the part or parts of the product which prove defective in material or work manship within one 1 year from date of purchase provided that the Buyer gives Symetrix prompt notice of any defect or failure and satisfactory proof thereof Products may be returned by Buyer only after a Return Authorization number RA has been obtained from Symetrix Buyer will prepay all freight charges to return the product to the Symetrix factory Symetrix reserves the right to inspect any products which may be the subject of any warranty claim before repair or replacement is carried out Symetrix may at its option require proof of the original date of purchase dated copy of original retail dealer s invoice Final determination of warranty coverage lies solely with Symetrix Products repaired under warranty will be returned freight prepaid by Symetrix via United Parcel Service surface to any location within the Continental United States At Buyer s request the shipment may be returned via airfreight at Buyer s expense Outside the Continental United States products will be returned freight collect The foregoing warranties are in lieu of all other warranties whether oral written express implied or statutory Symetrix Inc Limitation of Liability The total liability of Symetrix on any claim whether in contract tort including negli g
22. g and downward expansion simultaneously The unit shall occupy one rack space 1U The threshold of the compressor section shall be adjustable over a range of 40 dBu to 20 dBu via a front panel control The input to output ratio will be adjustable from 1 1 to 10 1 Control ofthe compressor release time shall be set by the front panel release control The compressor section will have a dedicated eight segment LED ladder that will display the gain reduction amount The Compressor Limiter Expander shall contain an integral peak limiter having a 20 1 ratio and adjustable threshold level A four segment LED display shall be provided to indicate the amount ofpeak limiter activity A front panel switch with LED indicator shall select between dual mono and stereo master slave operation Each channel shall have a bypass switch which defeats all front panel controls for that channel The Compressor Limiter Expander shall also contain a downward expander having a 1 1 5 expansion ratio with threshold and release time controls A four segment LED display shall be provided to indicate the amount of downward expansion The inputs shall be active balanced bridging designs terminated with 3 pin XLR AES IEC standard wiring and 1 4 TRS jack The input circuitry shall incorporate RFI filters The outputs shall be active balanced designs having equal source impedances and terminated with 3 pin XLR AES IEC standard wiring and 1 4 TRS
23. ge within the product s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons The exclamation point within an equilateral triangle is intended to alert the user of the presence of important operating and maintenance servicing instructions in the literature accompanying the product i e this manual Caution To prevent electric shock do not use the polarized plug supplied with the unit with any extension cord receptacle or other outlet unless the blades can be fully inserted Terms Several notational conventions are used in this manual Some paragraphs may use Note Caution or Warning as a heading Certain typefaces and capitalization are used to identify certain words These are Note Identifies information that needs extra emphasis A Note generally supplies extra information to help you to better use the 565E Identifies information that ifnot heeded may cause damage to the 565E or other equipment in your system Identifies information that if ignored may be hazardous to your health or that of others Controls switches or other markings on the 565E s chassis Strong emphasis Caution Warning CAPITALS Boldface Important Safety Instructions Please read and keep these instructions Heed and follow all warnings and instructions Install in accordance with the manufacturer s instructions Power Source This product is intended to operate from a power source t
24. hange the amount of amplification given to different frequencies a perfect amplifier increases the gain of all frequencies by the same amount Dynamics processors change the dynamic range of audio signals The dynamic range of an audio signal is the difference between its loudest and softest moments For audio equipment this is the difference between the noise floor residual noise output with no input signal and peak clipping the point at which the output clips or distorts A hypothetical black box having a noise floor of 90 dBu and a maximum peak output level of 24 dBu would have a dynamic range of 114 dB 24 minus 90 Audio storage devices like tape machines have a much narrower dynamic range a typical professional analog two track tape machine may have a dynamic range of 65 to 70dB If you ve used an analog tape recorder before then you are already familiar with the problem of setting recording level Record too hot and you get distortion record too cold and get noise in return Many musical instruments have dynamic ranges that exceed that of most tape recorders So how do we squeeze a 80 or 90 dB signal into a 60 or 70 dB window The answer lies in a common audio signal processor the compressor Compressors and Limiters A compressor or limiter monitors the level or amplitude of a signal and reduces the amplitude according to a rule whenever the signal level exceeds a predetermined level The predetermined level is known as
25. hat does not apply more than 250V rms between the power supply conductors or between either power supply conductor and ground A protective ground Chapter 2 connection by way of the grounding conductor in the power cord is essential for safe operation Grounding The chassis of this product is grounded through the grounding conductor of the power cord To avoid electric shock plug the power cord into a properly wired receptacle before making any connections to the product A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation Do not defeat the safety purpose of the grounding plug The grounding plug has two blades and a third grounding prong The third prong is provided for your safety When the provided plug does not fit your outlet consult an electrician for replacement of the obsolete outlet Danger from Loss of Ground Ifthe protective ground connection is lost all accessible conduc tive parts including knobs and controls that may appear to be insulated can render an electric shock Proper Power Cord Use only the power cord and connector specified for the product and your operating locale Use only a cord that is in good condition Protect the power cord from being walked on or pinched particularly at plugs convenience receptacles and the point where they exit from the apparatus Proper Fuse The user accessible fuse is a part of the IEC AC inlet connector
26. he back panel of the 565E Note Connecting an unbalanced cable here will result BALANCED in an output level that is 6dB lower than the output level you get if you use a balanced cable CHANNEL 1 OUTPUT BALANCED Output XLR 3 male connector wired Pin 1 ground Pin 2 high and Pin3 low Use this connector when you need a balanced XLR output The nominal signal level here is 4 dBu The wiring diagram for the BALANCED OUTPUT connector is reproduced on the back panel of the 565E Sidechain Key Input Connection Key Input 1 4 inch tip ring sleeve TRS phone jack wired tip return ring send and sleeve ground To trigger the compressor expander or limiter of the 565E from an external audio source use a cord with either a TS or TRS connec tor Connect the tip to the audio signal that you wish to use as a key trigger signal and connect the sleeve to ground if you use the TRS connector make no connection to the ring To externally process the sidechain signal use the ring of this connector to feed the sidechain signal to an external processing device and use the tip as the return form the external processing device The wiring diagram for the Key INPUT connector is reproduced on the rear panel of the 565E Audio Input Connections BALANCED UNBALANCED INPUT 1 4 inch TRS phone jack This connector is wired in parallel with the XLR input connector Connect either balanced or unbalanced sources here Use a tip sleeve
27. ifiers are fussy because an abnormally low load impedance generally means a visit to the amp hospital Thus it s important to know what the total impedance of the pile of speakers connected to the amplifier really is o RF systems are matched because we really are concerned with maximum power transfer and with matching the impedance of the transmission line keeps nasty things from happening Video signals composite baseband or otherwise should be treated like RF Some folks seem to believe that balanced unbalanced lines and impedances are related or even worse that they are associated with a particular type of connector Not so Unbalanced signals are not necessarily high impedance and balanced signals lines are not necessarily low impedance Similarly although 1 4 inch jacks are typically used for things like guitars which are high imped ance and unbalanced this does not predispose them to only this usage After all 1 4 inch jacks are sometimes used for loudspeakers which are anything but high impedance Therefore the presence of 3 pin XLR connectors should not be construed to mean that the input or output is low impedance or high impedance The same applies to 1 4 inch jacks So what is really important Signal level and to a much lesser degree the impedance relation between an output signal source and the input that it connects to signal receiver Signal level is very important Mismatch causes either loss of headroom o
28. illustration converts the 565E s balanced input into an unbalanced input at the input connector This works but is more susceptible to hum and buzz than the preferred method There is no level difference between either method You can drive unbalanced loads with the 565E s outputs by using the XLR connector with pin 3 left open In an emergency the show must go on you can ground pin 3 but if you have the choice leave it open If you must ground pin 3 it is must be grounded at the 565E rather than at the other end of the cable The price regardless of whether or not pin 3 is grounded is 6 dB less output level If your system is wired with pin 3 hot and you are driving an unbalanced load pin 2 must float The 1 4 inch input jack is paralleled with the XLR input In a large installation it is permissible to use one of the connectors as the input connection and to use either or both of the remaining connections for paralleling other inputs with the 565E The 1 4 inch output jack is a TRS tip ring sleeve jack wired for balanced operations This jack may also be used for unbalanced operation The unbalanced output is always 6 dB lower in level than the balanced output FROM BALANCED OUT FEMALE XLR N PIN 1 GROUND v PIN 2 HIGH a PIN 3 LOW FROM BALANCED OUT TIP MALE TRS PLUG TIP HIGH A RING LOW SLEEVE GROUND KE ne A SLEEVE FROM UNBALANCED OUT MALE TS PLUG TIP HIGH E SLEEVE GROUND
29. in reduction level as indicated by the meter or to a 0 dBu input level Vocal Level Smoothing This is one of the main uses for a compressor limiter in recording broad cast and live sound A compressor adds 25 15 12 40 fullness to almost any vocal by gently suppressing the loudest components of the audio signal This allows the listener to hear the quieter subtle sounds more clearly Recording and live sound engineers use this technique to help FAST SLOW 10 position the lead vocal out in front of the THRESHOLD dBu RELEASE RATIO X 1 backing instruments in a stereo mix CH1 COMPRESSOR Use a ratio between 2 1 and 4 1 Adjust the threshold until you see 6 9 dB of gain reduction on the highest peaks Remember that this is just a starting point because all vocalists and speakers have a different delivery Let your ears be the guide Removing Noise from Vocal Tracks It is usually more appropriate to clean up a noisy vocal track with a downward expander rather than a gate which is more abrupt in action The 565E s expander is smooth and can clean up vocals without cutting into phrasing CH1 EXPANDER 18 12 6 2 Q Set the expander threshold for 16 dB or more of gain reduction when the signal source is silent and 0 dB of gain reduction when the signal is present 10 BYPASS FAST SLOW Q Use the release control to make the expander follow the THRESHOLD dBu RELEASE phrasing Constant Level Paging
30. lcome Phone 425 778 7728 Fax 425 778 7727 Email symetrix symetrixaudio com Website www symetrixaudio com NE CEEE IE E D 565E a 00000000 3050 6666 80000000 3050 6666 oo FO O O O O 0 0 0 O 0 06 EXPANDER Symetrix O masses rast ronan o Mm nou ont mo see masses mae non n ons a Toma Front panel ME 5 E ANSER ng corr nf owt AT Symetrix ani au hoon nero usa Sad EN QUALI SDECHAI o C ol0 CHANNEL 2 INPUT CHANNEL 1 OUTPUT CHANNEL 1 INPUT SIDECHAI BALANCED BALANCED UNBALANCED meUr UNBALANCED BALANCI TYPICAL CONNECTIONS BALANCED ED BALANCED Rear panel O Symetrix Operator Safety Summary Equipment Markings CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN TO REDUCE THE RISK OF FIRE OR WARNING ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE AVI a RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR SEE OWNERS MANUAL VOIR CAHIER D INSTRUCTIONS No user serviceable parts inside Refer servicing to qualified service personnel ll ne se trouve a l interieur aucune piece pourvant entre repar e l usager S adresser a un reparateur comp tent The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user of the presence of uninsulated dangerous volta
31. lf of Symetrix This limited warranty gives the buyer certain rights You may have additional rights provided by applicable law tal or consequential damages including but not limited to damage for loss of revenue cost of capital claims of customers for service interruptions or failure to supply and costs and expenses incurred in connection with labor overhead transportation installa tion or removal of products or substitute facilities or supply houses 21 O Symetrix Servicing the 565E If you have determined that your 565E requires repair services and you live outside of the United States please contact your local Symetrix dealer or distributor for instructions on how to obtain service If you reside in the U S then proceed as follows At the Symetrix factory Symetrix will perform in warranty or out of warranty service on any product it has manufactured for a period of five years from date of manufacture Before sending anything to Symetrix contact our Customer Service Department for a return authorization RA number The telephone number is 425 778 7728 Monday through Friday 8AM 800 hours though 4 30 PM 1630 hours Pacific Time In warranty repairs To get your 565E repaired under the terms of the warranty 1 Call us for an RA number 2 Pack the unit in its original packaging materials 3 Include your name address daytime telephone number and a brief statement of the problem 4 Write the RA
32. low frequencies from the control signal or to boost the voice range frequencies in the control signal When the offending frequencies are removed or minimized the relative level of the desired frequen cies increases The expander can now tell the difference between the wanted and unwanted signals Use this technique in any situation where levels are nearly the same but the fundamental frequen cies involved are different Note The ability of the expander to discriminate between wanted and unwanted signals is partially determined by mic technique Be particularly careful of high frequency sounds entering the side or rear pattern of a cardioid mic Most cardioid mics exhibit a sharply rising off axis response characteristic at higher frequencies Check the off axis curve the lower one in the manufacturer s literature If there s only a 3dB to 6dB difference between the on axis frontal response and the off axis side or rear response in the 5kHz to 10kHz reason high frequency sounds will be picked up by the side or back of your mic Use the mic s directional pattern to keep other sources as far off axis as possible do everything you can do to extract all the source to source discrimination possible through good mic technique The sounds picked up by individual mics must be primarily the sound of the desired signal or the expander won t be able to tell the difference Hint You can save time and make life easier by listening to the ou
33. miting to make up for the 6dB drop in output level that occurs when you connect an unbalanced cable to the 565E s output or to reduce the 565E s output level to prevent overdriving the input stage of the next device in the signal chain IN JL BYPASS 0 40 O 10 20 20 O GAIN dB Note The unity gain position 0 of the Gain control is referenced to the balanced output connector If you are using the unbalanced output unity gain occurs when the Gain control is set to 6 dB LED display The LED display indicates the final output signal level Generally the first two or three LEDs should light when signal is present but the CLIP LED should never be on solidly It is usually all right if the clip LED flashes occasionally on peaks in the program material If you see the CLIP LED light monitor your final signal destination to be sure that you are not creating distortion by running audio levels that are too hot In Byrass switch The IN Bypass switch engages the 565E s processing circuitry when it is set to the IN position and places the 565E s processing section in bypass when the switch is set to the BYPASS position Note This is not a hard wire bypass the 565E will not pass signal unless the unit is powered and turned on The Stereo Link Control STEREO DuAL Mono switch The STEREO DuAL Mono switch is used to select o either Stereo or Dual Mono mode In Stereo mode both channels of the 565E respon
34. n is fast setup Refer to later chapters for explanation of the 565E s controls and functions O Connect the line level signal source for Channel 1 to either the female XLR input jack pin 2 hot or the 1 4 in TRS tip ring sleeve stereo 3 conductor input jack for Channel 1 Connect the line level signal return to either the male XLR output jack or to the 1 4 in TRS output jack for Channel 1 If you use the 1 4 in jack use a TRS plug for balanced circuits or use a TS plug for unbalanced circuits Additional information on the signal connections may be found on pages 13 14 of this manual If necessary repeat for Channel 2 Ignore the SIDECHAIN KEY INPUT connections for now Connect the AC input to an AC power source of the proper voltage and frequency as marked on the rear of the unit Caution Failure to connect the 565E to the proper AC mains voltage may cause fire and or internal damage Warning Lethal voltages are present inside the chassis There are no user serviceable parts inside the chassis Refer all service to qualified service personnel or to the factory O Make your initial switch and control settings as follows SwircH CoNTROL SETTING CHANNEL 1 EXPANDER THRESHOLD CONTROL Bypass RELEASE CONTROL 12 o CLOCK COMPRESSOR THRESHOLD CONTROL 10 120 cLock RELEASE CONTROL 12 o CLOCK RATIO CONTROL 2 1 APPROX 10 O CLOCK LIMITER THRESHOLD CONTROL Bypass OUTPUT GAIN CONTROL 0 120 cLock STEREO LINK STEREO DU
35. ndicates the amount by which the expander has reduced the level of the input signal The Compressor Controls THRESHOLD control The THRESHOLD control varies the compressor threshold pn HEOURRESSOR from 40 dBu to 20 dBu The compres 25 15 12 10 8 6 4 2 sor threshold is the level that the input oo0oo0oo0o0000 signal must reach before the compressor at 4 becomes active When the input signal 25 5 Ag 25 6 exceeds this threshold the compressor will reduce the output gain by the amount determined by the compressor 40 20 RSR RLON 1 E Ratio control setting THRESHOLD dBu RELEASE RATIO X 1 RELEASE control The RELEASE control allows tailoring of the compressor s recovery time to the program material Generally peak limiting is associated with short release times and compression or leveling is associated with longer release times The 565E s release circuitry has a unique dual release time feature designed to make life easier The dual release feature makes the release time partially program dependent giving you the best of both worlds fast release for short duration peaks and a longer release time for longer duration peaks The RELEASE control adjusts the speed of the longer of the two The compressor release time can be varied from 180 milliseconds to 2 5 seconds Ratio control The Ratio control determines the amount of compression that occurs for a given above threshold change in the input level The ra
36. orporated 6408 216th St SW Mountlake Terrace Washington USA declare under our sole responsibility that the product 565E Dual Compressor Limiter Expander to which this declaration relates is in conformity with the following standards EN 60065 Safety requirements for mains operated electronic and related apparatus for household and similar general use EN 50081 1 Electromagnetic compatibility Generic emission standard Part 1 Residential commercial and light industry EN 50082 1 Electromagnetic compatibility Generic immunity standard Part 1 Residential commercial and light industry The technical construction file is maintained at Symetrix Inc 6408 216th St SW Mountlake Terrace WA 98043 USA The authorized representative located within the European Community is World Marketing Associates P O Box 100 St Austell Cornwall PL26 6YU U K Date of issue April 1 1998 Place of issue Mountlake Terrace Washington USA Authorized signapare Dane Butcher President Symetrix Incorporated O Symetrix 23 O Symetrix Symetrix Inc 6408 216th St SW Mountlake Terrace WA 98043 USA Tel 425 778 7728 Fax 425 778 7727 Website http www symetrixaudio com Email symetrix symetrixaudio com
37. plug for unbalanced sources and a tip ring sleeve stereo plug for balanced sources CHANNEL 1 INPUT Or BALANCED UNBALANCED BALANCED INPUT XLR 3 female connector This connector is wired in parallel with the TRS input connector Use this connector when you need a balanced XLR input BALANCED Chapter 7 __ Connecting to Other Gear Matching Levels vs Matching Impedances In any audio equipment application the question of matching inevitably comes up Without digging a hole any deeper than absolutely necessary we offer the following discussion to hope fully clarify your understanding of the subject Over the years we have all had impedance matching pounded into our heads This is important only for ancient audio systems power amplifiers and RF Technically speaking the reason is power transfer which reaches a maximum when source and load are matched Modern audio systems are voltage transmission systems and source and load matching is not only unnecessary but undesirable as well o Ancient audio systems operate at 600 ohms or some other impedance value and must be matched both at their inputs and at their outputs Generally speaking if you are dealing with equipment that uses vacuum tubes or was designed prior to 1970 you should be concerned about matching These units were designed when audio systems were based on maximum power transfer hence the need for input output matching o Power ampl
38. quires an unbalanced line level audio signal for the key trigger signal not a DC voltage Wire the audio cable coming from the line level output of your trigger signal source Tip hot Ring no connection and Sleeve ground or Tip and Ring hot and Sleeve ground If your cable has TS connectors rather than TRS wire them Tip hot and Sleeve ground Ifyou wish to use a mic level trigger signal such as the output of the kick drum mic the mic level signal must first be boosted up to line level before it is connected to the Key IN jack of the 565E This is accomplished by routing the output of the mic to the input ofa mic preamp such as the Symetrix SX202 You can also use the mic preamp built into any mic input channel ofa standard mixing console In this case connect your microphone to the mic input channel and turn up the aux send control on just that channel Then route the aux send s line level output to the Key INPUT of the 565E Typically signals such as the output signal of a keyboard or a drum machine are already at line level so these outputs could be connected directly to the Key Input of the 565E Below is a hookup diagram for connecting a trigger signal to the 565E s CHANNEL 2 INPUT ANCED ALANCED CHANNEL 1 OUTPUT CHANNI TYPICAL CONNECTIONS GROUND PIN 1 77 LOW J PIN3 HIGH PIN 2 c BALANCED KEY BALANCED UNBALANCED INPUT UNBALANCED BALANCED BALANCED
39. r loss of signal to noise ratio Thus microphone inputs should only see signals originating from a microphone a direct DI box or an output designated microphone level output Electrically this is in the range of approximately 70 to 20 dBm Line inputs should only see signals in the 10 to 24 dBm dBu range Guitars high impedance microphones and many electronic keyboards do not qualify as line level sources The impedance relation between outputs and inputs needs to be considered but only in the following way Always make sure that a device s input impedance is higher than the output source impedance of the device that drives it Some manufacturers state a relatively high impedance figure as the output impedance of their equipment What they really mean is that this is the minimum load impedance that they would like their gear to see In most cases seeing a output impedance figure of 10 000 10K ohms or higher from modern equipment that requires power batteries or AC is an instance of this type of rating If so then the input impedance of the succeeding input must be equal to or greater than the output impedance of the driving device Symetrix equipment inputs are designed to bridge the output of whatever device drives the input i e to be greater than 10 times the actual source impedance Symetrix equipment outputs are designed to drive 600 ohm or higher loads 600 ohm loads are an archaic practice that won t go away You don
40. ration of the dynamic range processor The most common use of the sidechain is to make the action of the 565E s compressor limiter expander frequency dependent that is to make it respond more or less to certain frequencies by inserting an equalizer in the sidechain path Because the audio signal and the control signal remain completely separate even while the control circuit tells the VCA whether to turn the gain up or down you can equalize just the sidechain without changing the EQ in the main audio path This allows you to emphasize a frequency portion of the audio program so that this portion dictates the behavior of the processing for example you can boost the appropriate high frequen cies to make the compressor behave like a de esser or to de emphasize a frequency portion that is controlling the audio more than you would wish for example with beat heavy dance music cutting the low end can prevent the compressor from pumping and breathing with every kick drum beat Keep in mind that the threshold level becomes a function of the amount of overall gain through the equalizer including the boost This technique can be used with any frequency that can be con trolled by the equalizer One occasion for using an EQ in the sidechain is when low frequency signals transmitted through a desk or podium are triggering the 565E s expander unnecessarily You can solve this problem by using an equalizer in the sidechain to remove the
41. s into a barely discernible change at the output 1 dB Compressors are not the only devices to have an input output ratio Any device that is capable of changing the input output relationship can be said to have a ratio Thus expanders gates com pressors and limiters all fit this category An expander magnifies output changes for a given input change Thus once the input signal falls below threshold the expander changes the output by the amount of the ratio The 565E s down ward expander has an expansion ratio of 1 1 5 which means that a below threshold input signal that gets 10 dB quieter turns into an output signal that gets 15 dB quieter A gate can be looked at as an expander with an infinite expansion ratio Thus the slightest peak in the input signal from below threshold to above threshold switches the gate from closed to open Gain versus Output Level The Gain control compensates for signal level lost to compression As an example set the THRESH OLD control counter clockwise and set the Ratio control of the 565E for a 4 1 ratio Now adjust the THRESHOLD control for 10 dB of gain reduction as viewed on the compressor s gain reduction display The output level should be significantly lower than it was when the Threshold control was counter clockwise i e when no compression was being applied You supply the additional gain make up gain by adjusting the Gain control until the input and output signal levels match Release Tim
42. se the 565E s compressor section allows you to apply the right amount of compression without pumping or breathing Introduction The separate limiter section guards against peaks that lead to overload problems freeing the compressor section for settings specific to compression and not protection Trying to set a typical compressor for both compression and peak protection usually results in less than ideal settings The 565E s limiter protects against sharp peak signals while the compres sor smooths out the audio program for a silky pleasing finish The 565E s sidechain allows users to alter all three processing sections for special applica tions Inserting an equalizer at the sidechain can make the action of the 565E s compressor limiter expander frequency dependent Empha size or de emphasize a particular signal range to make the 565E respond more or less to certain frequencies Regardless of what your audio challenges may be the 565E offers a powerful variety of solutions In line compression limiting and expansion produce clean clear audio in any situation Innovative circuitry permits users to choose optimal settings without paying the price of extra distortion We recommend that you read this manual cover to cover You will find the answers to most of your questions inside Should you have any comments or questions please do not hesitate to contact us at the numbers addresses below Your calls are always we
43. se times O Symetrix Setting the Threshold Control The THRESHOLD control sets the audio signal level where the compressor expander limiter begins working In the case of the compressor or limiter the processor begins working once the signal has exceeded the threshold level For the expander it begins working once the signal has fallen below the threshold level For any of the three processors the THRESHOLD control setting also determines the degree or amount of gain reduction Thus for the compressor rotating the control counter clockwise towards 40 results in increasing amounts of compression For the expander counter clockwise rotation raises the level that the signal must exceed to pass through the expander untouched This has the effect of shutting off the signal once you reach and then pass the threshold level For most compressor applications moderate amounts of gain reduction are all that is required 3 9 dB at the most If you are using the compressor to minimize level changes of a wide range of program material automatic level control then higher amounts of gain reduction are needed In typical compressor applications program material with a very wide dynamic range calls for higher amounts of gain reduction than program material with less dynamic range Note With higher amounts of gain reduction slower release times are recommended Interpreting the Displays The 565E has one display per processing section
44. t need to terminate the output with a 600 ohm resistor if you aren t driving a 600 ohm load If you don t understand the concept of termination you probably don t need to anyway 11 O Symetrix O Symetrix The two facts that you need to derive from this discussion are o Match signal levels for best headroom and signal to noise ratio o For audio impedance matching is only needed for vintage equipment and power amplifier outputs In all other cases ensure that your inputs bridge your outputs meaning the inputs are in the range of 2 to 200 times the output source impedance Signal Levels The 565E is designed around studio professional line levels 4 dBu or 1 23 volts RMS The unit is quiet enough to operate at lower signal levels such as those found in semi pro or musical instru ment MI equipment 10 dBu or 300 millivolts I O Impedances The 565E is designed to interface into almost any recording studio or sound reinforcement applica tion This includes o 600 ohm systems where input and output impedances are matched o Unbalanced semiprofessional equipment applications o Modern bridging systems where inputs bridge and outputs are low source impedances voltage transmission systems The 565E s input impedance is greater than 20 kilohms balanced or 10K unbalanced The inputs may be driven from any source balanced or unbalanced capable of delivering at least 10 dBu into the aforem
45. tening to the equalizer output and adjusting the EQ to emphasize the sibilance in the source Remember that you re equalizing the signal to emphasize the sibilance not to sound groovy Let the 565E do that Do you have a recording where the cymbals drive you nuts Try the same technique on the overall mix Q Set the peak limiter threshold for 6 dB of gain reduction when Sam Screamer is on the system All normal signals will be slightly compressed and really loud signals will activate the peak limiter With these settings a shy person will be audible and the guy who thinks he has to shout won t be too loud or cause distortion 18 Chapter 9 Troubleshooting Troubleshooting Chart SYMPTOM PROBABLECAUSE Nooutput Check cables and connections Are inputs driven by outputs and outputs driving inputs Verify cables source and load by patching input and output connections together at the unit Check for AC power presence Did you connect the input cable to the Key IN jack instead of the Input jack Check input by plugging headphones halfway into the Key IN jack and listening for input signal Check output by plugging headphones into the output connector Hum or buzzin output Check input and output connector wiring refer to page 13 Ground loop check related system equipment grounding Are all system components on the same AC ground Distortion Check input signal Is it too hot or is it already distorted Check the output
46. the signal is present Q Use the release control to make the expander follow momentary pauses Q Since the successful implementation of this technique requires careful setting of the two threshold controls be prepared to fine tune the settings to match the levels of your system and the vocalist s style O Symetrix 17 O Symetrix KeyedBass As a special effect try using the signal from a kick drum to key a downward expanded bass This technique will tighten the signal start relationship between the two instruments Short RELEASE settings will result in a perfectly tight kick bass combination since the bass will not be heard until the kick drum is played To accomplish this feed the line level kick drum signal into the Key INPUT of the 565E while sending the line level bass guitar signal through the 565E CH1 EXPANDER CH1 COMPRESSOR CHI LIMITER CH1 OUTPUT O 48 12 6 2 25 45 41240 8 6 4 2 12 9 6 3 20 10 OdBu CLIP Pre 0000 00000000 0000 0000 En 0 OO O O 005 FROM BASS A EXPANDER X l q 10 BYPASS FAST SLOW 40 20 FAST SLOW 1 10 42 BYPASS 20 20 GUITAR a AUDIO O THRESHOLD dBu RELEASE THRESHOLD dBu RELEASE RATIO X 1 THRESHOLD dBu GAIN dB INPUT TO SIDECHAIN FROM AUDIO KEY INPUT OUTPUT PREAMP LP TO LINE INPUT KICK DRUM p BASS CHANNEL HIGROPEONE TO MIC INPUT S KICK DRUM QX gt EEE l Q RB MIC SPLITTER LS a Q The expander threshold control v
47. tio that is being controlled is the ratio between an above threshold change in the input level and the resulting change in the output level If the Ratio control is set to 10 1 then a 10 dB above threshold change in the input level would result in only a dB change in the output level Higher ratios are used where tighter control is desired such as when you want to control peaks in the audio signal and lower ratios are used for gentle smoothing of levels LED display The LED display indicates the amount by which the output level has been reduced by the compressor The Limiter Controls THRESHOLD control The THRESHOLD control sets the level to which the input signal must rise before limiting occurs Once the audio input signal rises above this threshold the output gain will be reduced by a ratio of 20 1 i e an above threshold signal increase of 20 dB at the input would result in only a 1 dB signal increase at the output CH1 LIMITER 12 9 6 3 O 5 LED display The LED display indicates the amount by which the output level has been reduced by the limiter 12 BYPASS THRESHOLD dBu The Output Controls Gan control The Gain control sets the final output signal level CH1 OUTPUT This control can be used to increase the output level up to 20 dB 20 10 OdBu CLIP or to decrease the output level by as much as 20 dB This control 0000 can be used if needed to restore signal level lost by compression or li
48. tput of the equalizer instead of the 565E s output that you re using in the sidechain Doing this allows you to hear the signal that will control the 565E and perhaps to find the range that you wish to emphasize or de emphasize more easily O Symetrix Front Panel Overview Chapter 5 Expander Section THRESHOLD control The THRESHOLD control varies the downward expander threshold from 10dButo BYPASS 18 12 6 2 The downward expander will engage when the audio OOO signal present at the input of the expander drops below l this threshold or when there is no signal present at the expander s input The downward expander gently lowers below threshold signals at a ratio of 1 1 5 a 1dB below threshold drop in signal at the expander s input results 10 BYPASS FAST SLOW ina 1 5dB drop in signal at the expander s output THRESHOLD dBu RELEASE CH1 EXPANDER 12 RELEASE control The RELEASE control allows the user to vary the downward expander release time from 250 milliseconds to 5 seconds The release time is the amount of time that it takes for the downward expander to push the output signal down to the level determined by the 1 1 5 ratio in response to an instantaneous below threshold drop in the input signal level Shorter release time settings cause the expander to act more quickly and longer release time settings cause the expander to act more slowly and smoothly LED display The LED display i

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