M80 User Guide_5 - Studio Technologies, Inc.
Contents
1. standards make the Model 80 suitable for continuous operation even for on air broadcast applications System Features One Stereo Input The differential input circuitry is compat ible with balanced or unbalanced signals having a nominal level range of 10 to 10dBu Using laser trimmed compo nents the input offers superior common mode signal rejection To achieve optimal audio performance the ExactCal calibra tion section matches the specific input level with the Model 80 s internal gain structure Two controls and four LEDs allow fast precise calibration Unlike other distribution amplifiers the Model 80 ensures that excellent audio performance can be achieved with little or no hassle In addition to separate left and right input connectors two input loop through con nectors are also provided This simple feature can make installation with related equipment much easier The loop through connectors allow the Model 80 s input source to be connected to another Model 80 or to yet another device Eight Stereo Outputs The Model 80 contains eight independent stereo output sections For compatibility with a range of facilities each output section can be separately configured for 10 or 4dBu nominal output level Each output features an electronically balanced circuit capable of driving balanced or unbalanced loads Operating an output in an unbalanced configuration does not cause its nominal output level to change2. 1 Type 5 x 20mm time lag Littelfuse 218 series or equivalent Rating 0 400A for 100 and 120V mains power 0 200A for 220 240V mains power Connectors Audio dual 4 inch 3 conductor phone jacks gold plated contacts Manufactured by Neutrik Mates with all plugs specified by EIA RS 453 AC Mains standard 3 blade plug meets IEC 320 specifications AC Mains Requirement 100 120 or 220 240V x 1096 factory configured 50 60Hz 100 120V 0 4A maximum 220 240V 0 2A maximum Dimensions Overall 19 00 inches wide 48 3cm 1 72 inches high 4 4cm 6 65 inches deep 16 9cm 1 standard rack space Weight 7 0 pounds 3 2kg Specifications and information contained in this User Guide subject to change without notice Model 80 User Guide Studio Technologies Inc
3. Model 80 while the headphone ear pieces are against your ears High sound pressure levels may be present Only after a signal is connected should you slowly put the headphone trans ducers near your ears Issue 5 October 1999 Page 13 Studio bola To confirm that a signal is present on the input of the Model 80 you can plug the headphones into the loop through con nectors associated with the left and right channels After ensuring that the level will not hurt your ears you can listen for the presence of audio and get an idea of the general quality of the source With a bal anced input signal you should hear the input in both the left and right earpieces of the headphones With an unbalanced source you would in most cases hear signal in only the left channel of the phones To confirm that signals are present on the eight stereo outputs you can plug the headphones into the left and right output jacks Outputs configured for 4dBu operation will be significantly louder in the headphones Since all Model 80 out puts are balanced you should observe signal in both the left and right earpieces Rapidly walking through the 16 output jacks will confirm the proper operation of the Model 80 Technical Notes Y Inch Plugs versus EIA RS 453 An incompatibility problem lurks between some 4 inch phone plugs and the jacks found on professional audio equipment While all the plugs seem to look the same some do
4. Short circuit resistant the rugged output Circuits can drive full signal levels into 600 ohm or greater loads Issue 5 October 1999 Page 7 Studio bola The Model 80 s architecture precludes the After careful study Studio Technologies need for individual output level trim poten concluded that these adjustments con tiometers With the input signal calibrated fused and often interfered with the pro using the ExactCal section the eight cess of getting maximum audio perform stereo outputs use 1 tolerance compo ance After checking with personnel in the nents to provide precise 10 or 4dBu field it became clear that what is desired outputs in virtually every distribution amplifier applications are multiple audio outputs all Audio Performance operating at a standard reference level The Model 80 is the result of exacting By implementing the ExactCal system the Circuit design combined with the latest Model 80 s internal operating level can be state of the art components Like all easily calibrated to match the input signal Studio Technologies products the Model Once this input level matching is accom 80 has survived tough listening evalua plished the eight stereo outputs can be tions by industry professionals These individually configured for a 10 or 4dBu veterans had the ears to guide us in nominal operating level In conclusion achieving the right performance The output trim pots are not included on the outcome
5. is a product that achieves Model 80 for the simple reason that better sonic excellence audio performance can be achieved without them Design Philosophy Most audio distribution amplifiers contain a level trim adjustment on each output Model 80 Front Panel EXACTCAL MODEL 80 STEREO ANALOG AUDIO DISTRIBUTION AMPLIFIER E RIGHT TRIM STUDIO o i D TECHNOLOGIES TEE TET LJ SKOKIE ILLINOIS U S A ar ia a Power Input Input level Right input 10 or 4 output level present LED level control calibration LEDs trim control configuration switches Model 80 Back Panel AC MAINS INPUT Ase INSTRUCTION MANUAL L 2a LES 5 AES Lam V AES Lm D N D N AA MODEL 80 e e o amp o e oe oe e wee M A WM M 7 wa A A A A A A NOTE M 7 j DISTRIBUTION AMPLIFIER oan Ett nmi M o e e e e FIER GALIY Balance E e 022 Diztoonov CE xo REMO En o nA nA n RAA n m RARA ence Oren Rs Ro STUDIO TECHNOLOGIES INC soj6oHe arn D e o SEE INSTRUCTION MANUAL o QUE mwstudio tech com TO QUALIFIED SERVICE PERSONNEL NEM J A 7 M7 FORDE Tae 7w MADE IN USA OUTS OUT7 OUT6 OUTS OUT4 OUT3 OUT2 OUT1 LOOP THRU INPUT AC mains Stereo line level Loop through Stereo line level connection outputs output input Issue 5 October 1999 Model 80 User Guide Page 8 Studio Technologies Inc Studiclook Installation In this section you will be installing the Model 80 in an equipment rack Audi
6. 1 stereo separate left and right input connectors Loop Through hardwired in parallel with input separate left and right loop through connectors Type electronically balanced direct coupled Input Compatibility can be connected to balanced or unbalanced signals Impedance 24k ohms Nominal Input Level 10 to 10dBu Input Level Control allows calibration over 10 to 10dBu input range Right Trim Control allows adjustment of right input level over a 3dB range nominal Maximum Input Level 27dBu balanced 21dBu unbalanced Common Mode Rejection 90dB DC and 60Hz 85dB 20kHz 60dB 400kHz typical Audio Outputs 8 stereo separate left and right output connectors Type electronically balanced direct coupled intended to drive loads of 600 ohms or greater can be connected balanced or unbalanced Nominal Output Level 10dBu 245mV or 4dBu 1 228V each output individually switch configurable Maximum Output Level Balanced 27dBu into 10k ohms 26dBu into 600 ohms Maximum Output Level Unalanced 21dBu into 10k ohms 20dBu into 600 ohms Output Impedance 50 ohms Frequency Response 10Hz 70kHz 0 0 5dB down 1dB 2 110kHz Distortion THD N 0 004 measured at 4dBu input 4dBu output 20Hz 20kHz S N Ratio 91dB 20Hz 20kHz ref 4dBu Crosstalk 75dB 1kHz ref 4dBu Issue 5 October 1999 Page 16 LED Indicators 5 1 power present 4 input level calibration Fusing
7. St o boka Model 80 Stereo Analog Audio Distribution Amplifier User Guide Issue 5 October 1999 This User Guide is applicable for serial numbers Model 80 M80 00360 and later Copyright 1999 by Studio Technologies Inc all rights reserved 5520 West Touhy Avenue Skokie Illinois 60077 U S A Telephone 847 676 9177 Fax 847 982 0747 www studio tech com 50200 1099 Issue 5 Studiclook Table of Contents Foreword 5 inyigere Wreri o q ep UU 7 What This User Guide Covers 7 System Overview ssssssseeeeeeeennnees 7 System Features oret evel eee ie rpecue ei 7 InstallatiOE sopa ode hd Ra Pago e Ded Lead A RR d 9 GODIIQUEAETOLD 2 cdi oH b deb bo idt 11 ODOLEATIOP e rontana aia n eias a a Ta 12 Troubleshooting cobi ora eoe errat brindan riens 12 Technical NOlBS uidi ronis eo abd ox mua ec b aru d 14 SDSCIIICallOrSs d ee eolee a additae 16 Block Diagram Model 80 User Guide Issue 5 October 1999 Studio Technologies Inc Page 3 Studio bola This page intentionally left blank Issue 5 October 1999 Model 80 User Guide Page 4 Studio Technologies Inc Ste to tools Foreword am pleased to present the Model 80 Stereo Analog Audio Distribution Ampli fier As both president and owner of Studio Technologies take a very personal approach when designing products Getting older 38 as of this writing has increased my a
8. ay be helpful to mark the correct input level and right trim adjustment points Use a grease pencil or a piece of adhesive tape so as not to damage the front panel Disconnect the 1kHz signal and con nect the normal audio source Output Level Selection Each of the eight stereo line level outputs is individually configurable for a 10 or 4dBu nominal output level Eight DIP type switches located on the right side of the front panel are used to set the output levels The legend on the switches corre spond to the output channel numbers A switch that is set to the up position sets its associated output channel for 10dBu A switch set to the down position sets the output for 4dBu A small screw driver may be of assistance when setting the switches Operation Now that you ve installed and configured the system you re ready to go You should find operation very easy as there is almost nothing to do on a day to day basis For peace of mind the ExactCal LEDs will give you a visual indication whenever audio signals are present on the Model 80 s input The LED labeled Lo will light whenever the input signal is within the range of 18dB below and 0 5dB above the nominal oper ating level The LED labeled Hi will light Issue 5 October 1999 Page 12 any time the input signal is greater than 0 5dB below the nominal operating level This sounds a bit confusing but isn t really so hard to understand As an example if
9. ctive Earth E Green Yellow Safety Warning The Model 80 does not contain an AC mains disconnect switch As such the mains cord plug serves as the disconnection device Safety consideration requires that the plug and associated outlet be easily accessible to allow rapid discon nection of mains power should it prove necessary As soon as mains power is connected the Model 80 s power present LED will light The unit is now ready for years of trusty service Configuration Input Level Calibration With the ExactCal calibration section it s simple to match the nominal level of the input signal with the Model 80 s internal Circuitry Two controls level and right trim along with four LEDs are the ExactCal operator controls The level control is a stereo device adjusting the input sensitiv ity for both the left and right inputs The right trim control allows the input sensitiv ity for the right channel to be adjusted over a 3dB range This allows compensa tion to be made for small differences in the left and right input levels Two LEDs labeled Lo and Hi are associated with each input They are provided as an aid to calibration as well as serving as signal present indicators Model 80 User Guide Studio Technologies Inc The following is a step by step procedure for using the ExactCal section to match an input signal with the Model 80 e Set the level control fully counterclock wise all the way to the left e
10. e Shield Switchcraft No 297 Neutrik NP3C or equivalent Unbalanced Connection Input amp Output EN gt ro En Sleeve Shield Switchcraft No 280 Neutrik NP2C or equivalent Caution For reliable audio interconnec tion the plugs you use must comply with industry standard RS 453 Switchcraft No 297 Neutrik NP3C or equivalent will work correctly Refer to the Technical Notes section for details Audio Input The Model 80 provides one stereo line level input It is electronically balanced and is compatible with balanced or unbal anced signals that have a nominal level range of 10 to 10dBu The ExactCal section allows precise level calibration with the connected input signal It is anticipated that in most cases a stereo signal will be connected to the input The Model 80 can also be used as a 1 input 16 output monaural distribution amplifier or as a dual 1 input 8 output monaural distribution amplifier Issue 5 October 1999 Page 9 Studio bola Prepare the input plugs so that tip is positive or hot ring is negative or cold and sleeve is shield The input jacks will also accept unbalanced inch 2 conductor phone plugs With unbal anced phone plugs tip is positive or hot and sleeve is shield If 3 conductor phone plugs are used to connect unbal anced signals connect positive or hot to tip and connect shield to ring and sleeve Loop Through The two loop thro
11. e Model 80 Stereo Analog Audio Distribution Amplifier was developed by Studio Technologies as part of its Studio Tools group of audio support products The Model 80 is designed to work ina large variety of applications Specific applications include audio production duplication broadcast and sound rein forcement All Model 80 functions meet or exceed the performance of the most expensive high end audio equipment What This User Guide Covers This User Guide is designed to assist you when installing configuring and using the Model 80 Stereo Analog Audio Distribution Amplifier System Overview The Model 80 from Studio Technologies Inc is the first distribution amplifier that meets the needs of the real world The stereo input is intended to connect to virtually any line level audio source The ExactCal input calibration section allows for optimal audio performance over a 10 to 10dBu input level range The eight stereo outputs meet exacting professional standards Capable of driving balanced or unbalanced loads each output can drive 26dBu into 600 ohms Using front panel switches each output can be individually configured for a nominal output level of 10 or 4dBu The front panel controls and LEDs make installation and setup a simple job The AC mains internal power is factory config ured for 100 120 or 220 240V 50 60Hz operation Components and construction Model 80 User Guide Studio Technologies Inc
12. ed to the Model 80 Depending on the version you have purchased 100 120 or 220 240Vac 50 60Hz is required Con firm what mains voltage is required by observing the selection boxes to the left of the AC mains connector on the back panel Whenever mains power is con nected the front panel power present LED should light If the LED is not lit confirm that the main power source is active hot and that the connector on the cord is securely mated with the plug on the back panel For safety in the event of a major internal failure or the connection of incorrect AC mains voltage the Model 80 contains a fuse inside the cabinet The fuse will open blow if the failure of an internal compo nent causes excessive current to be drawn from the internal power supply The fuse will also open should 220 240Vac be connected to a Model 80 that is config ured for 100 or 120Vac operation The fuse is intended to be replaced only by a qualified service technician This person will have the training to safely access the guts of the Model 80 and identify where a problem is located Incorrect Output Levels You must correctly set the input level and right trim controls for the eight stereo outputs to receive a precise 10 or 4dBu nominal output level These controls match the level of the audio input signal with the Model 80 s internal circuitry Refer to the Configuration section of this guide for detailed instructions Intermitten
13. ignals have a low source impedance and a high input impedance The dBu designation is be coming the standard for the professional audio industry 10 Output Level Reference To those of you who are technical nitpickers we feel than an explanation is in order Operational simplicity rather than historical convention led Studio Technologies to make the 10 outputs referenced to dBu rather than to dBV We are well aware that in the past a 10 output was often referenced to 1 volt not to 0 7747 When the Model 80 was first designed it was assumed that the 4 Model 80 User Guide Studio Technologies Inc Studiclooks output would be in dBu and the 10 output would be in dBV We soon real ized that this would cause cranium problems for many users A user monitor ing one of the Model 80 s outputs would expect to see a 14dB drop on their VU meter when going from the 4 to the 10 DIP switch position on the Model 80 s front panel They actually would be switching from a 4dBu output to a 10dBV output a difference of 11 78dB confusion would immediately reign To avoid this situation we took the liberty of keeping the 10 referenced to dBu This should in no way effect the ability of the Model 80 to inter face with other equipment while making life easier for everyone Model 80 User Guide Studio Technologies Inc Issue 5 October 1999 Page 15 Studio bola Specifications Audio Input
14. nd of the travel Supply a 1kHz sine wave to both the left and right line inputs Set the level of the source to be precisely the nomi nal operating level If for example the output of a console is connected to the input of the Model 80 the console output should be adjusted so that the meters read OdB or 100 If the output of the console is a 4 type then setting the console s left and right output levels to nominal should find the console output levels to be exactly 4dBu Slowly turn the level control clockwise As you increase the level watch the LEDs associated with the left channel The LED labeled Lo will light first then both LEDs will light then only the LED labeled Hi will light The correct setting is where both LEDs light Careful adjustment is required as the window where both LEDs light is somewhat less than 1dB Observe the LEDs associated with the right channel If they are both lit no adjustment of the right trim control is required If only one is lit adjust the right trim control using a small flat blade screwdriver so that both LEDs light We like the Xcelite R3324 screw driver it has the clear green handle and is commonly used to calibrate audio equipment Issue 5 October 1999 Page 11 Studio bola For practice mess up the settings of the level and right trim controls Again follow the calibration procedure and again get things set up correctly For future reference it m
15. not comply with the indus try standard called EIA RS 453 This standard defines the physical dimensions including the shape of the plug s tip It seems that some plug manufacturers don t bother to make the tip comply with the standard Why is this relevant to you Because the phone jacks used on the Model 80 do comply with the standard Issue 5 October 1999 Page 14 They expect to be mated with plugs that also meet the specification When interfac ing with the Model 80 be careful with the plugs you utilize Should a connection appear flaky sound noisy or make an intermittent contact the most likely prob lem is a nonstandard phone plug Replace the plug if this is the case You should find that all plugs from Switchcraft or Neutrik will work correctly specifically Switchcraft No 297 or Neutrik NP3C Definition of Level dBu Whenever possible Studio Technologies has opted to use the dBu designation as it seems to be quite rational Using dBm was fine when all audio line outputs were terminated with 600 ohm loads In this way it was easy to say that OdBm is 1 milliwatt dissipated in the known load i e OdBm across 600 ohms will measure 0 7747V In contemporary situations an output is rarely terminated with 600 ohms generally 10k ohms or higher The dBu designation is better because it refers to dB referenced to 0 7747V with no reference to load impedance This takes into account today s audio scene where s
16. o input and output connections will be made using the Model 80 s multitude of phone jacks AC mains power will be connected to the Model 80 System Components The shipping carton contains a Model 80 User Guide and warranty card Units destined for North America are shipped with an AC mains cord Your dealer or distributor will provide an AC mains cord for non North American destinations Mounting the Model 80 The Model 80 requires one space ina standard 19 inch 48 3cm equipment rack It is desirable to locate the Model 80 to allow easy access to both the front and the back panels The back panel contains the input and output connectors The front panel is used to access the calibration controls and output level switches The front panel also contains several LED indicators The Model 80 is secured to the equipment rack using two mounting screws per side Audio Inputs and Outputs The Model 80 s audio input and output connections are made using inch 3 conductor phone jacks The choice of phone jacks was simply a matter of real estate 20 XLR connectors don t quite fit on the back of a one rack space unit Don t be concerned about damage to your audio quality the jacks used in the Model 80 are manufactured by Neutrik of Switzerland and feature gold plated contacts for excellent performance Model 80 User Guide Studio Technologies Inc Balanced Connection Input amp Output Ring Sleev
17. ppreciation of the more subtle things in life be they a part of nature or the nuances contained in a well designed piece of electronic equip ment Do the technical and operational aspects of a product work together to feel right A Studio Technologies design is ready to go only when am com pletely satisfied Many fine people worked toward making the Model 80 happen Mitch Budniak ace consulting engineer designed many of the circuits Jim Cunningham contributed to the analog design Carrie Loving provided engineering support Ben Kamen designed the automatic testing routines Al Lux designed the printed circuit board Fred Roeck performed the mechanical design Joe Urbanczyk coordinated the safety testing and agency approvals Additional thanks to Timothy Powell of Metro Mobile Recording Glenview Illinois who provided his excellent ears when issues of sonic quality arose His extensive field and studio experience was extremely helpful in keeping me on the audio straight and narrow Please contact me with your questions comments and suggestions can be reached by voice at 847 676 9177 fax at 847 982 0747 or via the Internet www studio tech com Sincerely Gordon K Kapes President Model 80 User Guide Issue 5 October 1999 Studio Technologies Inc Page 5 Studio bola This page intentionally left blank Issue 5 October 1999 Model 80 User Guide Page 6 Studio Technologies Inc Introduction Th
18. t Audio Connections Should you experience audio connections Model 80 User Guide Studio Technologies Inc that seem to be flaky or intermittent refer to the Technical Notes section of this guide The 14 inch 3 conductor phone jacks used on the Model 80 are of very high quality conforming to the industry standard EIA RS 453 Some plugs do not meet this standard specifically in the shape of the tip conductor In rare cases you may have to replace plugs on inter connecting cables to remedy an intercon nection problem Switchcraft No 297 or Neutrik NP3C phone plugs will function correctly Headphones as a Troubleshooting Tool One of the simplest means of checking for the overall presence of a line level audio signal is to listen to the signal using a pair of stereo headphones The signal level and source impedance of contemporary audio output circuitry can easily drive headphones to quite a high sound pressure level Carefully used headphones are a great means of rapidly determining if signal is present on an audio line Note that in a few cases the plugs used by headphone manufacturers do not comply with the EIA 453 specifica tions for inch plugs You may want to designate a pair of headphones for line level testing and attach a plug of known quality We have found that even some very high quality headphones have non standard plugs be warned Warning Safety First Do not plug a pair of headphones into a jack on the
19. ugh jacks are electrically wired in parallel with the two input jacks With this arrangement several applications are possible such as allowing the input signals to be routed to another stereo input without the use of Y adapters The source signals would be connected to the input jacks The loop through jacks would be used to connect the source signals to the next piece of equipment using 14 inch 3 conductor patch cords Another application would be where more than one Model 80 is used to distribute the same input signal Two inch 3 conduc tor patch cords would link the loop through jacks on the first Model 80 to the input jacks on the second Model 80 Yet another application would be where the Model 80 is used as a 1 input 16 output monaural distribution amplifier The monaural input would be connected to the left input jack and a 4 inch 3 conductor patch cord would connect the left loop through jack to the right input jack Audio Outputs The Model 80 contains eight independent stereo line level outputs which are in tended for connection to a variety of ana log audio devices The outputs are Issue 5 October 1999 Page 10 electronically balanced and capable of driving balanced or unbalanced loads of 600 ohm or greater The outputs can be individually configured for a nominal output level of 10 or 4dBu so you can connect to all line level inputs with no hassle Prepare the output plugs so that tip is positi
20. ve or hot ring is negative or cold and sleeve is shield The output jacks will also accept unbalanced inch 2 conductor phone plugs With unbal anced phone plugs tip is positive or hot and sleeve is shield If a 3 conductor phone plug is used in an unbalanced application connect positive or hot to tip and connect shield to ring and sleeve AC Mains Power The Model 80 is internally configured to operate from either 100 120 or 220 240V 50 60Hz In most cases units shipped to North America are factory selected for 120V operation Units bound for Japan are selected for 100V while our friends down under and in Europe receive units set for 220 240V Before connecting the Model 80 to AC mains power check that it is config ured to match the local mains voltage Look on the back panel adjacent to the power entry connector for the configured voltage s Note that an incorrect configu ration could seriously damage the unit Should it be necessary to change the unit s operating voltage it must be performed only at the factory or by an authorized service technician The Model 80 uses an IEC standard con nector to mate with the AC mains cord The wire colors in the AC mains cord should conform to the internationally recognized CEE color code and must be wired accordingly Model 80 User Guide Studio Technologies Inc Studiclook Connection Wire Color Neutral N Light Blue Line L Brown Prote
21. you have a nominal 4 signal con nected to the Model 80 s line input and the ExactCal section has been used to calibrate the input the Lo LED will light when the signal is between 14 and t 4 5dBu the Hi LED will light when the signal exceeds 3 5dBu In most cases the input level control shouldn t be changed as it will change the input calibration In special applica tions you may want to use it as a fader simultaneously adjusting the level on all eight stereo outputs In the fully counter clockwise position the eight outputs are completely off Before you use the level control as a fader ensure that you mark the position of the knob where the input is calibrated If you change the input source you can use the ExactCal section to recalibrate the input Refer to the configuration section of this guide for details Each of the eight outputs are fully inde pendent You can patch reconnect or even short out an interconnecting cable without effecting the other outputs Using the front panel DIP switches you can change the output level of any or all of the outputs whenever you wish Troubleshooting If you re having problems getting the Model 80 up and running this section can help If you haven t read the other sections of this guide you should do so before proceeding Model 80 User Guide Studio Technologies Inc Studiclook If the Model 80 Doesn t Work At All A source of AC mains power must be connect
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