240 Owner`s Manual
Contents
1. CH2 OFF ON POWER THRESHOLD ATTACK RELEASE OUTPUT SWITCH Determines Determines Determines Sets the limit Sets the Sets the base Controls the Turns power the signal the rate at the rate at of how deep signal level line release final pro on and off level that will which the which the the gate will that drives rate of the cessed output cause the gate opens gate closes attenuate the the compres compressor level gate to open lets signals attenuates or signal when sor More or close through after cuts off the closed Drive gives attenuation sound more com pression Page 4 Aphex Systems Ltd Model 240 DULL LOGIC GATEDO SSY RID ER COMPRESSOR sively compressed and you will hear the sound becoming busier and fatter Regardless of the Speed setting the automatic time constants are working just faster or slower FEATURE COMPRESSION GATE Many other products combine a compressor and gate but there are problems making them work together Usually you have to just use one function That s because the compressor s release occurs during the gate s closure The gate is trying to reduce the signal level while the compressor is trying to raise it The compressor s gain release counter effects fights against the gate The Model 240 features a new design first introduced in the Aphex Model 230 Master Voice Channel The Easyrider Compressor is gain locked whenever the Logic Assisted Gate activates This2. i oO Solution Delivery Series Oa uAL LOGIC lS S Teo E SeSs4 Ri vpveR Caon PRESSOR Instruction Manual P N 999 4400 Revision 2 Released 03 04 2006 Manufactured by Aphex Systems Ltd 11068 Randall St Sun Valley CA 91352 USA APHEX S YSTEMS Copyright 2006 Aphex Systems Ltd All rights reserved Produced by Donn Werrbach Creation tool Adobe InDesign 2 0 Printed by Stuart F Cooper Co Los Angeles _ CJ INSTRUCTION MANUAL A MESSAGE FROM THE PRESIDENT Dear Aphex Customer Congratulations on your purchase of the Model 240 Dual Logic Gated Compressor We have combined two of our patented technologies the Logic Assisted Gate and the Easyrider Compressor in an innovative interactive way In an era of endless choices of low cost outboard processors processors built into mixing desks and software plug ins that all leave something to be desired we decided to introduce a product that cannot be duplicated in function or performance at any price In addition to the exclusive processing technologies we decided to bring these technologies together in an attractive easy to use package And we decided to bring it to market at a very attractive price As with all our products we are extremely proud of the ingenuity of design and the manufacturing quality of the Model 240 We love to hear from you our customers about your experiences with any of our products Our customer support is unmatched in
3. Balanced Outputs T EA SIMPLIFIED SCHEMATIC CD 39 Unbalancing loses no output level You retain full gain Ground Pin 3 Directly to Pin 1 Female XLR Do Not Carry Pin 3 Through Cable and Ground at Other End 1 2 39 Mono Phone Plug Page 20 Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED A SYRIDER COMPRESSOR PART 3 UNBALANCED to UNBALANCED Standard Cable Guitar Cord Mono TS Phone Plug Mono TS Phone Plug cle eT b PART 4 UNBALANCED OUT to BALANCED IN Standard Method Enhanced Method Pseudo Balanced Advantage Reduced Hum and Noise Pickup Mono TS Phone Plug Stereo TRS Phone Plug Mono TS Phone Plug Stereo TRS Phone Plug cir SS ip ira Sl _1D Guitar cord of Part 3 above usualy works just as well aw Not Used Male XLR Male XLR Mono TS Phone Plug Not Used Corsi Mono TS Phone Plug ira PART 5 Y INSERT CABLES Some equipment reverses the role of tip and ring Check your manuals Male XLR To Equipment Input ye Ground Shield This End Only Stereo Plug i gt ja Insert Jack Sleeve Tip Female XLR 20 i 3 From Equipment Output E EE Ground Shield This End Only Mono TS Phone Plug To Equipment Input CI ma Ground Shield This End gay a ie To TRS Insert Jack From Equipment Output CI ae Mono TS Phone Plug Ground Shield This End Only Aphex Systems Ltd Model 240 Page 2
4. COMPRESSOR Attack Release Ratio Threshold Knee GATE Attack Hold Release Threshold Depth GATE INSERT Connector Type Send Connector Type Return Nominal Operating Level Point of Insertion ANALOG AUDIO THD IMD Freq Resp FLAT OTHER SPECS Power requirements Power Consumption maximum Dimensions Depth Behind Front Panel Net Weight Shipping Weight INSTRUCTION MAnNnuA L 5 0 Specifications XLR 3F amp 1 4 in TRS phone Jack each channel Balanced may be used unbalanced 10KQ nominal 24dBu Greater than 70dB 60Hz OdB Switched between 10dBV and 4dBu channels independent XLR 3M and TRS 1 4 in phone jack XLR is Impedance Balanced may be used unbalanced TRS is unbalanced XLR amp TRS 660 XLR amp TRS 33Q Same as input determined by operating level switch 25dBu Unloaded Program dependent user variable release baseline 3 1 Fixed Medium Hard Variable 4 uSec to 100 mSec Variable 5 mSec to 500 mSec Variable 100mSec to 1Sec Variable 20 to 60dB Variable 0 to 80dB 1 4 TRS Phone Jack Balanced 1 4 TRS Phone Jack Balanced OdBu Between input stage and gate detector lt 01 4dBu Out lt 01 4dBu Out 5Hz to 65KHz 1dB 85 to 260V 50 60Hz 12 Watts 19 W x 1 75 H x 8 25 overall depth 482 6mm W x 445mm H x 209 6mm overall depth 7 5 190 5mm Rack mounted 6lbs 2 73kg lbs 4 1kg All specifications are subject
5. an Input Stereo Phone Plug Na No Connect Stops Ground Loops From an Output Stereo Phone Plug oa n m aa Female Male 2 1 9 3 No Connect Preferred for Line Levels Shield grounded at receiving end only Positives Stops ground loops and reduces noise Negatives None To an Input Male XLR No Connect Stops Ground Loops Aphex Systems Ltd Model 240 Page 19 CJ INSTRUCTION MANUAL Appendices PART 2 BALANCED OUT to UNBALANCED IN Voltage Balanced Outputs anced output stages in use today The following dia i grams show you how to properly unbalance each type of output If you follow these instructions you should have no problems 9 It was mentioned that there are several types of bal Pw 9 SIMPLIFIED SCHEMATIC Unbalancing loses half the output level You lose 6dB of gain Female XLR Don t Ground or Connect Pin 3 Transformer Balanced Outputs Mono Phone Plug bale mee at Unbalancing loses no output level You retain full gain Female XLR Ground Pin 3 Directly to Pin 1 Impedance Balanced Outputs Alternatively Carry Pin 3 Through Twisted Pair Cable 1a and Ground at Other End 39 Mono Phone Plug SIMPLIFIED SCHEMATIC gt Vv Unbalancing loses no output level You retain full gain Female XLR Pin 3 Doesn t Matter OK Grounded or Not Grounded Mono Phone Plug TASOS EE 0 Servo
6. holds the compression gain constant until the gate again opens when com pression is instantly returned to active duty and continues seam lessly Gating and Compression happily work together for the first time in history Even if the GATE DEPTH is set for zero the compres sion gate will operate as indicated by the threshold LED REAR KEY INSERT JACK Allows you to insert any kind of line level audio equipment into the signal path of the gate s threshold detector Common uses are the insertion of an equalizer to tune the detector to specific sounds or to inject an external Keying signal to open the gate in sync with another track The operating level at this jack is in the vicinity of OdBu You should set up your inserted outboard gear accordingly METER Dual two color bargraphs indicate both compression and gating for both channels Compression is shown as a green down going bar while gating drives a red dot downwards When the red dot is engulfed in the green bar it turns yellow for better contrast OUTPUT CONTROL Once all processing is set where you want it the output can be adjusted to the perfect level as indicated by the input meters of the following equipment JON LINK LOGIC ASISTED GATE EASYRIDER COMPRESSOR THRESHOLD O Sang DRIVE OUTPUT CH2 F OFF ON ATTACK AN RELEASE f ooms NALL lt 7 METERS Channel 2 controls are the same as Channel 1 Channels 1 and 2 each have a tri color bargraph t
7. hum will result from ground currents that flow from the ac power system It is sometimes very difficult to isolate and stop ground currents between unbalanced equipment but it is quite easy to clean up balanced gear That s why pro gear is always balanced The cost of balancing is that of more expensive connectors cable and electronics but the cost is worth it when you depend on your audio quality That s why the Model 240 is equipped with a fully balanced I O Now that we ve sold you on only using really expensive pro gear lets show you how to get away with the really cheap stuff At least from the standpoint of killing ground hum A ground loop is an ac current that has become routed through your audio ground system The cur rent comes mainly from ground potential differences that exist between different wall outlets that return to opposite phases at the power distribution panel Secondarily however many pieces of equipment con tain line filters and transformers that leak a small amount of ac power into the chassis and ground return You may once have had the experience of getting zapped by touching two pieces of gear at the same time That illustrated the ground loop effect going Page 15 eH g 6 0 Appendices straight through you No matter what you do you may not be able to prevent some of your equipment from generating ground currents The most likely cul prits are digital products because they use switching power su
8. or hole punching With the simplicity of just two controls Drive and Release you can get fat and punchy compression or smooth and natural gain riding and anything in between Drive The Easyrider Compressor has a fixed internal threshold so getting more or less compression means driving it with more or less level The Drive control adjusts the signal gain ahead of the compressor to accomplish that It does not affect the Gate Threshold Speed The Easyrider Compressor has a complex set of time constants that adapt to the sound wave characteristics The basal time constant can be set by the user with the Speed control This can be looked at like the release time control on other compressor limiters With faster speed shorter release time the audio will be more aggres LINK OFF ON Causes the dual channels to become a stereo pair forcing both channels to track compression and gating Glows when signal is below threshold gati ing Serves to bypass channel 1 or 2 independently unless the Compression Link switch is in When linked either IN OUT switch operates both channels Logo glows green indicating power is on Determines how long the gate stays open before it is allowed to close release LOGIC _ASISTED GATE Solel HOLD Y n C EASYRIDER COMPRESSOR DRIVE OUTPUT Wl EEY y Yil REV g Da SN y AT OFF ON THRESHOLD O h Wed a 4 7 me d ATTACK 7 NN RELEASE
9. 1 feo g INSTRUCTION MAnNnuUuA L APPENDIX F HELPFUL WIRING TABLE Also see next page TABLE 2 TYPES OF ACTIVE BALANCED INPUT OUTPUT CIRCUITS amp INTERFACE WIRING OUTPUT TYPE Int Unbalanced 2 Unbalanced 3 Voltage Balanced 4 Voltage Balanced 5 Impedance Balanced 6 Impedance Balanced Cross Coupled Balanced Aphex Servo Bal anced Cross Coupled Balanced Aphex Servo Bal anced Wire single conductor with a shield coax style POSITIVE HIGH NEGATIVE LOW POSITIVE HIGH NEGATIVE LOW POSITIVE HIGH NEGATIVE LOW i SHIELD GND NC Optional see Note 6 POSITIVE HIGH NEGATIVE LOW POSITIVE HIGH NEGATIVE LOW POSITIVE HIGH NEGATIVE LOW WIRING DIAGRAM INPUT Resulting Interface erface from OUTPUT to INPUT TYPE METHOD LEVEL Unbalanced Balanced Unbalanced Balanced Unbalanced Balanced Unbalanced Balanced Unbalanced Pseudo Balanced Unity see Note 4 for Gain Unbalanced wiring 6dB Loss Unbalanced Page 22 Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED CHSY RID ER COMPRESSOR NOTES The following notes are referenced in the text and in Table 2 on the preceding pages Note 1 ADDITIONAL READING
10. A AND HOW IT AFFECTS CABLE SHIELD CONNECTIONS The three main contacts on an XLR or TRS and the accepted wiring assignments shown above are only part of the picture The standard for terminat Aphex Systems Ltd Model 240 ing ground is Pin 1 Sleeve But which ground It could be connected to audio signal ground or chassis ground depending on the method of grounding used by the equipment manufacturer In all Aphex prod ucts audio ground and chassis ground are one and the same at all I O jacks This is just good common sense engineering practice which is what you would expect from us course Unfortunately many prod ucts are designed so that the noisy currents from the shield drain into signal ground instead of chas sis ground This practice creates a real hum and noise problem for end users The appropriate overall grounding scheme of an audio system would be a lot easier to predict without this problem The standard balanced line wiring recommendation from Aphex Engineering is this In the majority of cases maximum noise rejection occurs when the shield is connected to the input ground only espe cially in locations with high levels of RFI That means the sending end shield should be left disconnected However if you already have cables with the shield connected at both ends go ahead and try them out If you are connecting a fairly simple audio system it may be fine as is A word on optional shield connections Conn
11. Due to the extensive protective measures used it is highly unlikely a catastrophic power supply failure will ever occur However if it does you should contact the factory or a competent service technician to affect repairs There are no user serviceable parts inside Aphex Systems Ltd Model 240 ACCEPTABLE POWER RANGE 85 to 265V 50 to 60Hz Page 7 e H og 3 0 Using the 240 INSTRUCTION MAn L Figure 3 1 Front Panel View EASYRIDER COMPRESSOR OUTPUT pwei THRESHOLD O Koin y Fpi dy YALL S S S S gute ire Sa SOR Costa 6hteo essen oer Comenessom 3 1 LEARNING THE LOGIC ASSISTED GATE 3 1 1 The Easiest Gate Books aren t much help in learning how to use a Noise Gate effectively Only direct experimentation with audio sources can bring you to any point of pro ficiency Luckily the Logic Assisted Gate of the Model 240 is by far the easiest full featured gate to master and use well 3 1 2 Logic Assistance What makes the Logic Assisted gate different is the digital logic that is used to absolutely guarantee the gate opens holds and releases exactly the same way as set by the controls every time Standard Noise Gates operate on the principle that the audio wave itself not only triggers the gate but the power in the wave is used to force open the gate and hold it open When the wave is low in power such as a transient drumbeat or a spoken voice the gate may open t
12. FICATIONS 12 5 2 ARCHITECTURAL SPECIFICATIONS 13 6 0 Appendices 14 Appendix A Balanced and Unbalanced Lines and Operating Levels 14 Appendix B Dealing With Grounds and Hum 15 Appendix C Proper Wiring Techniques 17 Appendix D Standard Cable Wiring 18 Appendix F Helpful Wiring Table 22 Patent Notice 24 Aphex Systems Ltd Model 240 Page 3 foes g 1 0 Controls and Indicators with Quick Setup LOGIC ASSISTED GATE Patent 5 334 947 The Model 240 features the award winning Aphex Logic Assisted Gate technology that has been so widely acclaimed since its first introduction with the Aphex Model 612 Expander Gate It never hesitates or chatters Once triggered even by a microscopic tran sient it progresses fully through the attack hold and release sequence All parameters are fully adjustable to let you optimize the gating effect Threshold Range 60 to 20dB Adjust to reliably open the gate let sound through but reject unwanted background noise The Gate can be effectively turned off by turning the threshold all the way to 60cB Attack Range 4uS to 100mS Set to the fastest setting that does not cause a noticeable click when the gate opens Slower settings may be useful for effects Hold Range 5mS to 500mS Balance HOLD with RELEASE to obtain the best gating effect Usually a longer hold time allows you to use a shorter release time This can help whe
13. SUGGESTIONS Sound System Engineering by Don Davis and Carolynn Davis Howard W Sams and Co Handbook for Sound Engineers The New Audio Cyclopedia Edited by Glen Ballou Howard W Sams and Co and Sound Reinforcement Handbook by Gary Davis and Ralph Jones Hal Leonard Publishing Corp For more information on the Pin 1 Dilemma see the June 1995 issue of the Journal of the AES Vol 43 No 6 Audio Engi neering Society New York This issue is dedicated to Shields amp Grounds Note 2 TABLE 2 LEVEL CHARACTERISTICS unity gain verses 6dB loss Diagrams 1 2 and 4 through 8 The effective interface gain will remain at OdB for all of the interfaces shown Diagram 3 Balanced to Unbalanced This configuration should be used with equipment incorporating a conventional active balanced output stage Most non Aphex equipment uses this kind of output stage because of its simplicity and low cost Therefore you will find yourself using diagram 3 fairly often when interfacing typical equipment together In this case the interface gain will be 50 down giving a 6dB loss of level This is because each output driver has fixed gain and supplies only half the balanced output amplitude You can usually compensate for the loss by adjusting the output level or input level settings on the associated equipment Note 3 XLR GROUND DROP ADAPTERS A word on using XLR ground drop adapters and mic cables A secondary advan tage to not using the XLR case lu
14. als The following are not covered a Voltage conversions b Units on which the serial number has been defaced modified or removed c Damage or deterioration 1 Resulting from installation and or removal of the unit 2 Resulting from accident misuse abuse neglect unauthorized product modification or failure to follow instructions contained in the User s Manual 3 Resulting from repair or attempted repair by anyone not authorized by Aphex Systems 4 Occurring from shipping claims must be presented to shipper WHO IS PROTECTED This warranty will be enforceable by the original purchaser and by any subsequent owner s during the warranty period so long as a copy of the original Bill of Sale is submitted whenever warranty service is required WHAT WE WILL PAY FOR We will pay for all labor and material expenses for covered items We will pay return shipping charges if the repairs are covered by the warranty LIMITATION OF WARRANTY No warranty is made either expressed or implied as to the merchantability and fitness for any particular pur pose Any and all warranties are limited to the duration of the warranty stated above EXCLUSION OF CERTAIN DAMAGES Aphex Systems liability for any defective unit is limited to the repair or replacement of said unit at our opti and shall not include damages of any other kind whether incidental consequential or otherwise Some States do not allow limitations on how long an implied warranty la
15. cate a sweet spot for the particular sound track 5 Readjust the Drive to obtain enough compression to ride the gain or get the density you need This may be as little as 3 4dB of compression or as much as 20cB That s it It s just that simple 3 3 COMBINING GATING AND COMPRESSION Using the Logic Assisted Gate and the Easyrider Compressor is easy As described above they are very Page 9 CJ INSTRUCTION MANUAL Using the 240 cooperative Simply adjust the gate first followed by the compressor in the order they appear on the front panel 3 4 STEREO LINKING The Model 240 is a dual channel device that can be stereo linked Normally only the compressors are stereo linked by pressing the Compression Link button This links the baseline compression together but still allows independent compression activity for transient control The advantage of that is maintain ing perfect stereo balance but avoiding cross chan nel ducking on single channel transients The sound remains much more natural Gating is left independent in order to facilitate the best possible noise reduction When Stereo Linked the two IN OUT switches become interconnected so either one will send both channels out of bypass Page 10 Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED EASYRIDER COMPRESSOR 4 0 Warranty amp Service 4 1 Limited Warranty PERIOD One year from date of purchase SCOPE All defects in workmanship and materi
16. e become low impedance A few exceptions might be outputs from passive mixers instrument pickups electric guitars and some key board synthesizers It is generally ideal to drive any audio line from a low impedance and receive into a high impedance Generally a minimum 1 10 ratio is possible This is called bridging This has become modern practice and all balanced inputs are normally running 10K ohms or higher impedance Because of these developments it is now no longer as critical to consider impedance when dealing with interfacing pro line level equipment impedance matching is mostly a requirement of the past A word on impedance and interfacing adapters If you are connecting between two line level devices and they have different connectors example 1 4 phone to XLR or vice versa you do not need to use an impedance matching transformer With very few exceptions you are strictly dealing with a difference in connector types and should only use hard wired adapters or cables for this situation APPENDIX D Standard Cable Wiring In relation to 1 4 phone jacks you may see the terms TS and TRS as abbreviations Here is a what that means TS refers to the Tip Sleeve or mono 2 Page 18 conductor type and TRS refers to Tip Ring Sleeve or stereo 3 conductor type 1 4 phone connectors This applies to jacks female connectors and plugs male connectors Note We recommend using only conve
17. e several types of circuits that are used by different manufac turers These different types of output circuits all look just about alike to any balanced line but they act dif ferently when driving an unbalanced line You need to observe the proper cable wiring for each type of output circuit We strongly recommend that you refer to your various equipment manuals to find out what is used in each case before hooking up to unbalanced lines When connecting a balanced output to a bal anced input however you don t need to know what kind of balanced output you are dealing with Simply treat it generically PART 1 BALANCED OUT to BALANCED IN 1 4 TRS Phone to 1 4 TRS Phone Balanced Cables XLR to XLR Female Male 19 2 3 9 9 3 OK for Microphones Standard store bought cable Shield grounded at both ends Positives Good for microphones Negatives May cause ground loops through the shield grounds if used to connect equipment together a a 1 OK Standard store bought cable Shield is grounded at both ends Positives Both ends are interchangeable Negatives May cause ground loops through shield contacts oO _ iI BETTER Custom cable Shield is grounded at receiving end only Positives Stops ground loops and reduces noise Negatives Should be oriented so lifted shield is at sending end No Connect A XLR to 1 4 TRS Phone Balanced Cables From an Output Female XLR To
18. ect ing the cable shield of a balanced line at both ends creates unnecessary ground loops which may carry noise and hum currents that can be amplified Con necting the shield only at the sending end instead of the receiving end may exaggerate common mode noises at the receiving input stage It can actually increase RFI and noise more than having no shield at all Because of the Pin Dilemma mentioned above you may be forced in some situations to experiment with how the cable shield is connected to ground to eliminate a pesky hum or radio interfer ence problem It might be good to try XLR ground drop adapters see Note 3 as a method of trying these conflicting methods out and being able to change easily if necessary IMPEDANCE Regardless of inaccuracies it has become more or less standard over the years to refer to balanced lines as low impedance and unbalanced lines as high Page 17 eH OC Appendices INSTRUCTION MAn L TABLE 1 BALANCED amp UNBALANCED CONNECTOR WIRING STANDARDS 3 Pin XLR 1 4 TRS Phone Standard Wiring Convention Balanced Ground Shield Earth Screen Pins Ring O Negative Signal Reference Return Low Common 1 4 TS Phone Standard Wiring Convention Unbalanced Shell Ground Shield Signal Reference Return impedance The fact is however that both balanced and unbalanced lines are operated at low imped ance in modern practice owing to the fact that all output stages hav
19. erything you can think of Usually a combination of all these methods will be needed to completely clean up a badly humming audio system Balance Out the Audio Remember balanced lines are inherently hum free If you can balance out your unbalanced equipment you will be able to stop the hum Pseudo Balancing You will find in Appendix D an interconnecting method called Pseudo Balanced This works when connecting an unbalanced output to a balanced input This breaks up the ground loop by requiring the shield to be grounded only at one end For best results always ground the shield only at the receiving end Level Interface Units Aphex manufactures the Model 124A Level Interface box which is designed to electronically convert two unbalanced inputs and outputs into two balanced inputs and outputs and at the same time translate the 10dBV IHF unbalanced levels to the pro 4dBu balanced levels This cost effectively gives your non professional unbalanced equipment a fully profes sional I O equal to the world s best pro audio gear Seriously consider putting one of these on each unbalanced piece of gear you use Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED EASYRIDER COMPRESSOR Avoid Transformers The use of balancing transformers is an option but you will invariably lose audio quality due to trans former limitations Try everything else first Appendix C Proper Wiring Techniques A true balanced line should be used where
20. g as a ground is the ability to use barrel style XLR ground drop adapters hard wired female to male XLR adapters with Pin 1 disconnected These can be used on one side of the cable to disconnect the ground as discussed earlier If the case lug is tied to the cable s shield with or without Pin 1 the cable will still be grounded to the equipment s ground though the XLR ground drop s case XLR ground drops are useful especially for live sound situations where the same stock of XLR cable may be used for line level patching and or for patching microphones The reason is that XLR cables used for microphones should never have the shield disconnected at one end This is a safety issue for the performing artist microphones should always be grounded Note 4 If you have an unbalanced output but have a balanced input the pseudo balanced configuration may help deal with ground loop hum However it is possible to wire this as an unbalanced interface To wire unbalanced use a coax cable with a single conductor and a shield wire as follows Output From connect the ground contact to the cable shield con nect the positive contact to the positive conductor Input To connect the ground and the negative contacts to the cable shield connect the positive contact to the positive conductor Please note that this in fact occurs by default when plugging an unbalanced cable with a 1 4 TS Tip Sleeve phone plug into a TRS Tip Ring Sleeve phone
21. h fidelity audio cables ee di Figure 1 Balanced Line Model Figure 2 Unbalanced Line Model Balancing If both conductors are identical insulated wires that are twisted together then they form a balanced line This describes telephone lines microphone cables and most professional audio cables Typical balanced cables include an additional shield wrap around the twisted pair but this is not strictly required for bal anced lines to work properly Many people because they have more experience with unbalanced wiring think that balanced is con fusing Believe it or not balanced lines are really easier to understand than unbalanced There is no grounding issue with balanced and the way it works is perfectly natural and simple Balancing naturally rejects hum and noise and eliminates all sorts of com plications in interfacing Balanced transmission works something like this Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED EASYRIDER COMPRESSOR Your balanced input stage looks at the two wires and detects only the potential voltage difference between them Anything that is the same on the two wires for all practical purposes as seen measuring from ground is called a common mode signal and is cancelled out by the differential amplifier Figure 1 illustrates how the hum is induced into both wires equally and therefore is cancelled out Since the balanced line has wires that are twisted together each wire tends to pic
22. his is what happens in other compressor gate products It greatly limits their usability in combination The Model 240 fixes that problem by gating the gain reduction of the com pressor while the gate is acting In other words the compression is stopped and cannot release while the gate is closed or closing This provides perfect cooperation between the gate and compressor at all times It also has the added advantage of smoothing out the compression during sound pauses Instead of having to attack all the way back into full gain reduction whenever the sound Aphex Systems Ltd Model 240 ComrRessorR COMPRESSION R78 Figure 3 2 Jumper Locations one per channel again starts it is already sitting at the right gain reduc tion and just continues tracking along seamlessly You don t get the front edge breath exaggeration or chiff of typical compressors If or any reason you decide you don t want compression gating to take place you can dis able the feature by moving internal jumpers one per channel 3 2 5 Brief Compressor Tutorial One of the advantages of the Easyrider Compressor is its ultimate simplicity with only two controls to adjust Here s an example of how to set it up successfully 1 Start audio through the Model 240 2 Set the Gate off by setting its threshold full CCW 3 Adjust the Drive control to get something like 6dB of compression 4 Adjust the Speed control from slow to fast to lo
23. jack Note 5 Some electronically balanced output circuits from other manufacturers exhibit problems when the negative output amplifier is shorted to ground to in order to drive an unbalanced load The grounded output amplifier pumps current onto the ground which may cause distortion or cause the amplifier to fail When wiring this type of output be careful to leave the negative contact unterminated Note 6 Shield Option Connect receiving end only See text preceding Table 2 titled THE PIN 1 DILEMMA AND HOW IT AFFECTS CABLE SHIELD CONNECTIONS Note 7 Single Ended Impedance Balanced Note 8 It is possible to wire this as an unbalanced interface To wire unbalanced use a coax cable with a single conduc tor and a shield wire as follows Output From connect the ground and the negative contacts to the cable shield con nect the positive contact to the positive conductor Input To connect the ground contact to the cable shield connect the positive contact to the positive conductor Aphex Systems Ltd Model 240 Page 23 Page 24 Patent Notice INSTRUCTION mMenwu Fwu This product is protected under one or more of the following Aphex patents 4 578 648 4 633 501 4 843 626 4 939 471 5 115 471 5 155 769 5 334 947 5 359 665 5 422 602 5 424 488 5 450 034 5 463 695 5 483 600 5 485 077 5 612 612 5 737 432 5 848 167 5 896 458 5 898 395 5 930 374 6 266 423 Aphex Systems Ltd Model 240
24. k up the same amount of induction from external sources Induction will create no significant voltage difference between the wires hence the noise or hum will not be picked up by the differential input stage It can be seen that the signal generator driving the twisted pair will cause a difference between the wires and that signal will be readily picked up by the dif ferential input stage One of the beauties of the bal anced line is that it is completely independent from ground Nothing is connected to ground at all nor does it care about ground Nevertheless most pro fessional cable has an overall shield wrap that is intended to be connected somehow to ground You may well ask why and the answer is less than glo rious Simply nothing is perfect not even balanced cable Under some circumstances the shield can over come extreme interference problems that can t be adequately rejected by the twisted pair alone Things like 2 way radios television transmitters and light dimmers can induce very heavy interference that may be reduced by shielding You are going to find virtu ally all balanced cables include a shield so you need to deal with it even if it is not actually needed That subject will be addressed a little later Unbalancing Unbalanced wiring works a little differently Figure 2 shows the basic plan In this case the wires are not twisted they are coaxial The unbalanced input stage is somewhat like the balanced in
25. ld is too high 4 Begin turning the Threshold CCW until drum beats start popping the Gate open At first only the hardest beats will pop through Find the point where you can get all the desired weaker beats 5 Increase the Hold time until drums don t quench between pattern beats 6 Increase the Release time to make the drum trails sound more natural but still quenched enough to quiet the in between noises and crosstalk from other drums 7 Slow up the attack time just to see how it affects the drum attack Find the setting you like most 8 Reduce the Depth to the point where you get enough noise attenuation but not necessarily a deep dark sonic abyss unless it s what you want That s about it Most users will get the nack within a few minutes You will probably discover numerous gating effects that you like while experimenting One thing the Logic Assisted Gate can do that no other Gate can is to attack very slowly while still trigger ing positively every time Try really slowing the attack down and hear the almost backwards drum effect it produces 3 2 USING THE GATED EASYRIDER COMPRESSOR 3 2 1 Automatic Adjustment The Easyrider Compressor takes into account what other compressors don t the audio wave s complex energy level It makes using compression exceptionally easy by making adjustments automatically Aphex Systems Ltd Model 240 DUAL LOSIC GHeTTeED HSY RIDER 3 2 2 Limits of Conventional Comp
26. lector switch on the rear panel If not enough compression drive can be attained using the 4dBu setting then switch it to 10dBV 2 6 KEY INSERT JACK The signal that is sent to the gate s threshold detec Figure 2 2 Key Insert Adapter Cable For The Model 240 Mono TS Phone Plug From Equipment Output CI Ma Ground Shield This End Only To Equipment Input CI Mono TS Phone Plug Page 6 gt Tip To TRS Key Insert Jack ID Ground Shield This End Only Aphex Systems Ltd Model 240 90 260V 50 60Hz 15W DUAL LOSIC GHT ED EASYRIDER COMPRESSOR tor passes through the Key Insert Jack so you may insert an equalizer or external key source With no plug inserted the jack s switches normal the signal through With a plug inserted the path is broken and must be completed through an external unbalanced path See Figure 2 2 for an example of a proper break out adapter cable 2 7 POWER SUPPLY The 240 is internally powered from a standard IEC power receptacle on the rear panel Be sure you use a power cord that is approved for use in your jurisdic tion Soft start overload foldback limiting and accross the line voltage spike protection is incorporated to protect the power supply from damage that might be caused by component failure or power line disturbances If the internal fuse blows out a catastrophic failure has occurred and simply replacing the fuse will not fix the problem
27. n gating repetitive sounds like drums The gate can be held long enough to transition the beats and then a faster release can gate out the rumble and noise more effectively The HOLD setting should always be at least equal to the ATTACK setting to insure the logic properly assists the attack function Release Range 100mS to 1S Causes the gate to close stop audio very abruptly to very softly This should be set to bring the best gating effect to the kind of sound you have POWER INDICATOR YELLOW LED HOLD INSTRUCTION MAnNnuUA L Depth Range 2 to 80aB Sets the maximum amount of gain reduction the gate will generate At 80dB the gate is virtually a switch The audio will gate completely off Less depth will allow the gate to reduce he signal but not necessarily cut it off The best setting is one that reduces the unwanted noises just enough to be useful Deep gating can sometimes be apparently extreme making the sound seem chopped especially with high background noise levels when the rack is naked Gated tracks added to a mix will have their gating effects masked by other tracks allowing deeper gating to be used in many cases EASYRIDER COMPRESSOR Patent 5 483 600 Further distinguishing the Model 240 is the award winning Easyrider Compressor that adapts to the complex waveforms of audio signals to optimize loudness consistency and density of sound streams without creating unwanted side effects such as pumping
28. ntional 1 4 phone plugs with the Model 240 and with all other audio equipment Professional patch bay cords using brass PJO55 telephone type plugs are designed only for patch bays and will not make proper contact with standard 1 4 phone jacks The following instructions show all the different ways you will probably ever need to hook up your 240 as well as any other equipment you may own You will see that connecting balanced outputs to balanced inputs is ultimately simple and the same cable will work for all flavors of output stages Connecting a balanced output to an unbalanced input requires a little more knowledge and care You should refer to your equipment manuals and determine the type of balanced output stage that is provided then use the correct transition cable as depicted in this section Improper transition cables can cause crosstalk hum and distortion problems within your system TYPES OF BALANCED OUTPUTS Believe it or not there are at least 5 types of balanced output stages in use today They may be placed into two main classes transformer balanced and Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED E EASYRIDER COMPRESSOR transformerless balanced usually called active bal anced Transformer balanced outputs are becoming outdated because of their high cost and their sonic limitations However they can still be found on a lot of older equipment Within the transformerless class there ar
29. o display gain reduction caused both by compression and gating Comnpression is indicated by a downward moving red bar Gating is indicated by a downward moving dot that appears yellow while nested within the red bar and green when outside of the red bar Gating and compression have separate scales Aphex Systems Ltd Model 240 Page 5 e H g 2 0 Installation amp Interfacing 2 1 RACK INSTALLATION INSTRUCTION MAnNnuA L The Model 240 occupies a single rack space 45mm or 1 3 4 inches of a standard EIA equipment rack When rack mounting use appropriate cushioned rack screws Never restrict air flow through the device s vents When installing the units into a rack distribute the units evenly Otherwise hazardous conditions may be created by an uneven weight distribution Connect the unit only to a properly rated supply circuit Reliable earthing grounding of rack mounted equipment should be maintained Try not to position the 240 directly above devices that generate excessive heat such as power amplifiers unless adequately ventilated or near equipment with heavy transformer hum fields Figure 2 1 Rrar Panel View BALANCED OU Cal 2 2 AC LINE CONNECTION Use only a power cord that carries approvals for use in your location The 240 s internal power supply is designed to operate from all nominal power sources from 100 to 240 volts a c at 50 60Hz without requir ing the user to change any settings In case of failu
30. oo late not fully open chatter or perhaps not even open at all With Aphex s Logic Assisted Gate these things can t happen If the threshold is reached even by the shortest transient the logic system takes over and operates the gate without depending on the power of the sound wave Logic will cause the full attack hold and release to occur as determined by the front panel adjustments Even with a very slow attack set ting a short transient like the leading edge of a snare tap will bring the gate open fully This translates to extremely consistent gating with a threshold setting that is far less critical The full range of expression can be gated successfully whereas with a standard Noise Gate it s almost impossible to find a reliable threshold setting that won t miss some of the beats or misfire on crosstalk IMPORTANT NOTE To insure the logic function the HOLD time should always be set to a value at least equal to the ATTACK time Page 8 COMPRESSION LINK Vga on OFF ON EASYRIDERT COMPRESSOR OUTPUT m O OFF ON 3 1 3 Brief Gate Tutorial Here is a basic procedure for getting the benefits of the Logic Assisted Gate Of course different sources like voices drums and guitars need different settings This example uses a recorded or live drum track 1 Set Threshold and Depth full CCW 2 Set Attack Hold and Release full CCW 3 Start the drum track You won t hear it yet because the gate thresho
31. or one circuit use a second or third circuit that is tapped off the same 120 volt phase in your distribu tion panel That means all outlets should be on odd or even numbered circuit breakers That s because as you go down the column the circuit breakers tap into alternating legs of your incoming electric power Be sure you re always on the same leg You can tell you re on the same leg by measuring the ac voltage between the hot slots of the different outlets you ve chosen It should be very low or zero That will remedy 50 percent of the cases Check the Cord Polarity Page 16 INSTRUCTION MANUAL For products that have 2 wire power cords try revers ing one of the power cords in the socket That may reduce the ground current generated by the internal electronics of the offending gear Redirect Ground Loops Sometimes it just comes down to brute force ground ing That means providing such heavy low resistance ground current paths that little current is left to flow through your audio grounds You can try adding heavy gauge for example 12 gauge copper wire from chassis to chassis You will need to locate a metal screw that solidly binds to the metal chassis of the gear You may even need to drill a hole through the chassis and install a screw yourself Equipment in rack shelves can have their chassis grounded to the metal rack frame by a heavy wire and the frame itself can act as a brute force ground You just have to try ev
32. pplies that require heavy line filters to pre vent conducted EMI from going out of the box These line filters often take the ground leakage current right up to the UL safety limits Although it probably won t kill you that is a lot of ground loop current for audio cables to handle There are basically three ways to attack the problem of a ground loop First is to eliminate it from its source and the second is to re route it through another path The third is to balance out your unbal anced audio interfaces Identify the Sources A good way to identify grounding problems is to use a multimeter to check the ac voltage between the chassis of your various gear when no audio cables are hooked up and all gear is plugged in and switched on Just start touching the two probes to the metal chassis of different pieces of gear Ideally you should always see zero volts Warning You may see as much as the whole line voltage between two different chas sis It does happen This voltage between chassis will be responsible for your ground loop problems If you find there is more than about 1 volt between equipment grounds you should start looking for a remedy Commonize the Power Try plugging all of your equipment into the same outlet strip Get one that has enough outlets in one strip or string more than one together Of course you need to make sure you don t overload the one ac cir cuit your strip is plugged into If the load is too great f
33. put stage because amplifies a difference signal but this time it is the difference between two non symmetrical conduc tors To make things even less symmetrical the outer conductor is connected to ground at both ends The principle is that the outer shield conductor shields the inner conductor from induced noises This can only work well if the cable is relatively short and the ground at each end of the cable is somewhat equal Aphex Systems Ltd Model 240 i e there is no grounding difference that can cause current to flow through the shield conductor Grounding difference is a serious problem in studios because often the equipment grounds are connected to power outlet grounds and there can be a sig nificant difference of ac voltage between alternating wall outlet grounds For this reason unbalanced sys tems can sometimes never be made hum free and just changing one piece of equipment in a studio can cause hum to appear somewhere else When you are using unbalanced gear it is a very good procedure to power all your equipment from one large power isolation transformer At the very least make sure all equipment is powered together off the same distri bution panel circuit same circuit breaker Appendix B Dealing With Grounds and Hum Ground Loops Many people equate this term with hum and that s just about the bottom line of it If you have a ground sensitive system like unbalanced audio equipment for example then
34. re do not attempt to change the internal fuse because it will never blow unless the power supply fails cata strophically The power supply will need to be serviced by a competent service technician in such a case 2 3 LINE INPUT CONNECTIONS The audio line input connectors are located on the rear panel Both standard XLR 3F and 1 4 TRS types are provided The TRS jack is paralleled with the XLR so they load each other and shorting one brings down the other Do not plug two different sources into the two jacks at the same time 2 4 LINE OUTPUT CONNECTORS There are two impedance balanced output connec tors located on the rear panel one 1 4 TRS phone type and one XLR 3M type They are driven from the same output circuit but can be used at the same time Elo to feed separate equipment The outputs can be used unbalanced If you intend to make an unbalanced output from the XLR jack simply take hot from pin 2 and use pin 1 for ground Leave pin 3 unconnected Unbalancing the TRS jack simply requires taking the tip as hot and sleeve as ground If you ground the sleeve you will also be grounding pin 2 of the XLR which will make it operate as an unbalanced output Refer to Appendix C amp D for more information on the proper wiring of balanced and unbalanced lines 2 5 LEVEL SWITCH The Model 240 is designed to operate at either pro fessional 4dBu or semi pro 10dBV levels Each channel has its own level se
35. ression Audio sources vary considerably in their peak and average power levels For example when sounds are already compressed and dense their peaks are sup pressed and the average energy level is relatively high Uncompressed natural sounds have much less aver age energy compared to their peak level Each sound has its own peak to average ratio and wave envelope shape That s why no particular attack and release set tings of a conventional compressor can work well on everything You always have to fiddle with a regular compressor s settings to get a good sound and still it may not ever be quite right That s because it can t follow and adjust itself for the varying audio charac teristics 3 2 3 Overcoming the Limitations The Easyrider Compressor constantly changes its attack and release characteristics to adapt to varying audio waveforms It can hold up a consistent punch and density over a whole mix of sounds but it can handle the expression and density of a single instru ment or vocal track equally well You can use it to ride gain smoothly over an audio track or to bring all the elements closer together in loudness and density without ever getting the sucked out effect of regu lar compression 3 2 4 About Our Gated Compression It would be a disadvantage if the Logic Assisted Gate were to start attenuating the noise as it should while the compressor gain releases bringing the noise right back up at the same time T
36. sts and or do not allow the exclusion or limitation of incidental or consequential damages so the above limitations and exclusions may not apply to you This warranty gives you specific legal rights and you may also have other rights which vary from State to S 4 2 SERVICE INFORMATION If it becomes necessary to return this unit for repair you must first contact Aphex Systems Ltd for a Return Authorization RMA number which will need to be included with your shipment for proper identification If available repack this unit in its original carton and packing material Otherwise pack the equipment in a strong carton containing at least 2 inches of padding on all sides Be sure the unit cannot shift around inside the carton Include a letter explaining the symptoms and or defect s Be sure to reference the RMA number in your letter and mark the RMA number on the outside of the carton If you believe the problem should be covered under the terms of the warranty you must also include proof of purchase Insure your shipment and send it to Aphex Systems Ltd 11068 Randall Street Sun Valley CA 91352 PH 818 767 2929 FAX 818 767 2641 Aphex Systems Ltd Model 240 Page 11 e H g 5 1 GENERAL SPECIFICATIONS LINE INPUTS Connector Type Input Z Maximum Input Level MIL CMRR Nominal Gain Operating Level OUTPUT Connector Type Output Z Balanced Output Z Unbalanced Nominal Level Maximum Output Level MOL
37. tandard electronic equipment rack Power The unit shall have a self contained power supply operating from the ac line Primary voltage connectorization and agency listings shall be appropriate to meet local requirements Aphex Systems Ltd Model 240 Page 13 on g 6 0 Appendices Appendix A Balanced and Unbalanced Lines and Operating Levels Interfacing all types of equipment with balanced and unbalanced lines and can sometimes be trouble some First you have to somehow connect balanced to unbalanced and then you have to deal with dif ferent levels This tutorial will teach you about the principles of balanced and unbalanced lines wiring standards and how to effectively interface them Standards Professional audio equipment usually comes equipped with inputs and outputs that are balanced using 3 pin XLR connectors and sometimes 1 4 inch phone jacks as well This equipment most often is designed to operate at 4dBu a professional industry stan dard That translates to a magnitude of 1 23 volts RMS Root Mean Squared Consumer gear has unbalanced I O as standard usu ally on RCA jacks The normal operating signal level follows the IHF Institute of High Fidelity standard of 10d BV or 0 316 volts 316mV RMS Converting to dBu dimensions this works out to be the same as 7 79dBu There is therefore a difference of 11 79dB between pro and consumer operating levels Grounding There is the notion that some king of ear
38. te this equipment It is suggested that the user use only shielded and grounded cables to ensure compliance with FCC Rules CE Page 2 Aphex Systems Ltd Model 240 Copyright 2006 by Aphex Systems LTD All rights reserved All Aphex products are trademarks or registered trademarks of Aphex Sys tems LTD Other brand and product names are trademarks or registered trademarks of their respective holders DUAL LOGIC GATEDO EASYRIDER COMPRESSOR Table of Contents 1 0 Controls and Indicators with Quick Setup 4 2 0 Installation amp Interfacing 6 2 1 RACK INSTALLATION 6 2 2 AC LINE CONNECTION 6 2 3 LINE INPUT CONNECTIONS 6 2 4 LINE OUTPUT CONNECTORS 6 2 5 LEVEL SWITCH 6 2 6 KEY INSERT JACK 6 2 7 POWER SUPPLY _ 7 3 0 Using the 240 8 3 1 LEARNING THE LOGIC ASSISTED GATE 8 3 1 1 The Easiest Gate 8 3 1 2 Logic Assistance 8 3 1 3 Brief Gate Tutorial 8 3 2 USING THE GATED EASYRIDER COMPRESSOR 8 3 2 1 Automatic Adjustment 8 3 2 2 Limits of Conventional Compression 9 3 2 3 Overcoming the Limitations 9 3 2 4 About Our Gated Compression 9 3 2 5 Brief Compressor Tutorial 9 3 3 COMBINING GATING AND COMPRESSION 9 3 4 STEREO LINKING 10 4 0 Warranty amp Service 11 4 1 Limited Warranty 11 4 2 SERVICE INFORMATION 11 5 0 Specifications 12 5 1 GENERAL SPECI
39. the industry so please do not hesitate to contact us Very Truly Yours Marvin Caesar Safety Declarations TO PREVENT FIRE OR SHOCK HAZARD DO NOT EXPOSE THIS DEVICE TO RAIN OR MOISTURE DO NOT REMOVE THE COVER NO USER SERVICEABLE PARTS INSIDE SHOCK HAZARD REFER SERVICING TO QUALIFIED PERSONNEL ONLY DO NOT OPEN ATTENTION AFIN DEVITER DES CHOCS ELECTRIQUES N ENLEVEZ PAS LE COUVERCLE IL N Y A AUCUNE AVIS RISQUE DE CHOC ELECTRIQUE PIECES D ENTRETIEN A L INTERIEUR REFEREZ LES NE PAS OUVIR REPARACIONES A UNE PERSONNE QUALIFEE CAUTION For protection against electric shock do not remove the cover No user serviceable parts inside WARNING This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the operating guide may cause interference to radio communica tions Operation of this equipment in a residential area is likely to cause interference in which case the user will be required to correct the interference at his own expense The user is cautioned that changes and modifications made to the equipment without approval of the manufacturer could void the user s authority to opera
40. thly ground exists out there that sinks all the noise and acts as some kind of a shield You see wires connected to ground rods and water pipes that are supposed to get a good ground This is not a correct interpreta tion of grounding from an audio standpoint Proper grounding of equipment and wiring is important and you will gain a better understanding of that as you read along Balanced vs Unbalanced Every audio signal is connected through a circuit The circuit must contain two conductors to create a com plete return path In other words a signal voltage is conducted to a piece of equipment by injecting a cur rent into a wire That current has flow though to the destination through the wire and return back to the source through another wire Since audio is an alter nating voltage swinging through negative and posi tive polarity the current through the two conductors changes direction each alternate half cycle Which Page 14 INSTRUCTION menu FwL wire is the source and which is the return alternates accordingly In this regard balanced and unbalanced lines are the same They both need two conductors What makes a system unbalanced is when one of the wires is formed into a tube that wraps around the other conductor without touching it such that the outer conductor can be said to shield the inner conductor This describes all of the coaxial cable used for video cable TV and radio as well as most of the hig
41. to change without notice Page 12 Aphex Systems Ltd Model 240 DUAL LOSIC GHT ED EASYRIDER COMPRESSOR 5 2 ARCHITECTURAL SPECIFICATIONS Basic Description A two channel linkable dynamics processor comprising a noise gate and a compressor for each channel The compression of the two channels shall be linkable for stereo operation The gate and compression elements shall be cooperative when the gate is cutting down the channel gain such that any compression gain reduction that was present when the gate started attacking will be locked steady so as not to counter effect the gate The Noise Gate shall comprise a logic operated process whereby any threshold detect regardless of transience or weakness above threshold causes the full attack and hold sequence to complete The threshold detecting circuit shall have a rear panel insert jack to allow insertion of outboard processor devices between the trigger source and the threshold detector The Compressor shall comprise an adaptive dynamic range compressor with multiple time constants that can adjust to varying audio waveforms to provide optimized compression Physical Properties The device shall be packaged in an all metal chassis measuring 19 482 23mm wide 1 75 44 42mm high with an overall depth of 8 25 210mm Depth behind the front panel shall be approximately 7 178mm The device shall have a net weight of approximately 6lbs 2 73kg and is capable of mounting in a s
42. ver your equipment allows Use twisted pair shielded cable For unbalanced wiring you should use high grade low capacitance shielded wire for best results If you have an unbalanced output but have a balanced input the pseudo balanced configuration may help deal with ground loop hum This method and others are illustrated in Table 2 CONNECTOR WIRING STANDARDS The 3 pin XLR 1 4 63 5 mm TS mono phone and the 1 4 63 5 mm TRS stereo phone are the most commonly used line level connectors in pro audio Less common is the use of the RCA phono jack which is essentially a consumer type connector The XLR and the TRS are three conductor and are used for balanced connections The TS and the RCA are two conductor and are used for unbalanced connections In addition to the three main contacts on an XLR there is also a grounding lug contact This lug is con nected to the connector s case shell In all Aphex products audio ground and chassis ground are one and the same Aphex products that use XLR con nectors tie Pin to the XLR case automatically There fore it is not necessary to use the XLR case ground lug This also makes possible the use of XLR ground drop adapters see Note 3 TABLE 1 The wiring convention shown is now stan dardized in 17 countries including the USA Please note that any equipment that still uses Pin 3 as posi tive on XLR connectors is not adhering to the stan dard THE PIN 1 DILEMM
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