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Model 50/51 User Guide 

Issue 6, September 2004

Studio Technologies, Inc. 

Page 33

terminated with 600 ohm loads. In this way 
it was easy to say that 0dBm is 1 milliwatt 
dissipated in the known load (i.e., 0dBm 
across 600 ohms will measure 0.775V). 
In contemporary situations an output is 
rarely terminated with 600 ohms; gener-
ally 10k ohms or higher. The dBu desig-
nation is better because it refers to dB 
referenced to 0.775V, with no reference to 
load impedance. This takes into account 
today’s audio scene where signals have a 
low source impedance, and a high input 
impedance. The dBu designation is be-
coming the

 

standard for the professional 

audio industry.

StudioComm equipment is designed to 
interface with audio signals that have nom-
inal signal levels of –10dBV and +4dBu. 
You might wonder why dBV came into 
the picture. Most people don’t realize that 
equipment that utilizes “–10” levels usu-
ally mean –10dBV—substantially different 
from –10dBu (–10dBV = –7.78dBu). The 
dBV designation is simply a different way 
of measuring signal level and is often used 
when dealing with portable or consumer 
audio equipment. The dBV designation 
refers to dB referenced to 1.0V, rather than 
dBu which refers to 0.775V.

“Hot” Disconnection of the Model 51 
Control Console

Should you need to relocate the Model 51 
while your StudioComm system is oper-
ating, there is no reason why you can’t 
disconnect the 5-conductor cable, move 
the unit, and then connect it again. If the 
Model 51 is disconnected while it is op-
erating, the current operating parameters 
are saved in nonvolatile memory and the 
Model 50 Central Controller will continue 
to operate as it did when the link was 
broken. No clicks, pops, or other noises 

will occur when the Model 51 is again 
connected. The Model 51 will go through 
its standard power-up sequence, send a 
message to reset power-up defaults, then 
send the operating parameters as stored 
in its memory. You may notice a brief inter-
val of silence while the Model 50 responds 
to the reset defaults message.

Control Room Mono Function

Many arguments where had while design-
ing the control room monaural function. 
Was the function supposed to be a true 
mono function, sending the sum of left 
and right to a separate mono control 
room output? Was mono to be the sum 
of left and right sent to both left and right 
channels? What about level build up with 
phase coherent signals that are in both 
the left and right channels? After much 
head scratching it was realized that the 
mono function that most people are ac-
customed to is really a means of observ-
ing the character of a stereo mix, and not 
a “true” mono function. To observe the 
stereo image of a mix you need to sum 
the left and right signals, drop the level of 
the sum, and send the result out the left 
and right outputs. In our implementation, 
we drop the level by 6dB. This is what 
many recording consoles implement, and 
is what the StudioComm does too! We 
understand that specialized applications 
such as mastering and film mixing may re-
quire a more exotic mono function. Sorry, 
our hardware simply can’t support it!

Talent Amplifier Mono Function

The Model 35 and Model 38 Talent 
Amplifiers each contain a monaural 
switch. The mono function sums the left 
and right input signals, drops the level of 
the sum by 6dB, and sends the sum to 
both the left and right outputs.

Содержание 35 Talent Amplifier

Страница 1: ...e and Related Components User Guide Issue 6 September 2004 This User Guide is applicable for systems consisting of Model 50 serial number M50 00457 and later Model 51 serial number M51 00457 and later 2004 by Studio Technologies Inc all rights reserved www studio tech com ...

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Страница 3: ...ation Topics 17 Configuration 19 Model 51 Configuration Chart Main Functions 22 Model 51 Configuration Chart Alternate Functions 23 Operation 25 Troubleshooting 30 Technical Notes 32 Specifications 36 Appendix A 39 MIDI Messages 40 Block Diagrams Model 50 Central Controller Model 51 Control Console Model 35 Model 38 Talent Amplifiers Model 70 Interface ...

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Страница 5: ...onsulting engineer designed many of the circuits Jim Cunningham contributed to the analog design Larry Leviton wrote the excellent micro controller software Al Lux designed the printed circuit boards Carrie Loving designed the graphics Fred Roeck performed the mechanical design Joe Urbanczyk coordinated the safety testing and agency approvals Many thanks to Bob Tjarks professional audio sales mana...

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Страница 7: ...ole work together to provide performance and features for use in advanced applications The units interconnect using a standard 5 pin MIDI style cable Circuitry in the Model 50 separately routes any of seven stereo inputs to the control room meter studio headphone and dub outputs with com mands provided by the Model 51 Control Console If you have MIDI software that supports the StudioComm system yo...

Страница 8: ... button allows the sum L R of the select ed source to be sent as the control room output Meter Output The meter output provides a stereo output that follows the source selected for the control room The signal is not affected by the control room level circuitry but is post mono The meter output is intend ed to be connected to VU or PPM type meters or meter panels that contain series current limitin...

Страница 9: ...stem exclusive MIDI messages The Model 51 Control Con sole speaks this language and in most applications a Model 51 will be utilized In special applications the Model 50 Central Controller can be connected directly to a MIDI bus allowing the creation of a fully automated recording or audio routing system For more information on MIDI support refer to Appendix A Configuration The Model 51 Control Co...

Страница 10: ...off button and level control Configure button switches between normal operation and configure mode Change the control room level listen in mono L R select output A or B or reduce the level by a preset amount Source selection for control room CR studio headphones and dub three columns of LEDs show the currently selected sources Model 51 Back Panel Connection for external talk to studio and talk to ...

Страница 11: ...rol Console any of the seven stereo inputs can be assigned to the talent amplifier output The talk to phones function allows com munications voice audio to be sent to the talent amps The talent amplifier out put is short circuit protected Error condi tions are displayed by the Talent Amplifier Over Current LED on the Model 50 s front panel Each Model 35 and Model 38 Talent Amplifier can drive two ...

Страница 12: ...dividual head phone mix solving the classic problem of wanting more me in the phones Like the Model 35 the Model 38 is linked with a Model 50 Central Controller by a single cable Installation In this section you will be installing the Model 50 Central Controller in an equip ment rack Audio input and output con nections will be made using the Model 50 s multitude of inch phone jacks One or more Mod...

Страница 13: ...he equipment rack using two mounting screws per side Audio Inputs and Outputs The Model 50 s line level 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 21 XLR connectors don t quite fit on the back of a one rack space unit Balanced Input and Output Connections Sleeve Shield Switchcraft No 297 Neutrik NP3C o...

Страница 14: ... the Technical Notes section for details on setting amplifier sensitivity Dub Output The Model 50 contains a stereo line level output which is intended for connection to a variety of analog audio devices The dub output is electronically balanced and capable of driving 600 ohm loads or greater With the input impedance of most audio devices at 10k ohms or greater the dub output can easily drive 10 o...

Страница 15: ...ounting For details refer to Mounting Options in this section Connecting the Model 50 to the Model 51 A standard 5 conductor MIDI style cable is used to connect the Model 50 to the Model 51 a cable is included with your system Just connect the cable between Meter Output Sleeve Common Tip Left output Ring Right output Switchcraft No 297 Neutrik NP3C or equivalent a nominal level of 4dBu and is capa...

Страница 16: ...to mains power check that it is con figured to match the local mains voltage Look on the back panel adjacent to the power entry connector for the configured voltage s Note than 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 50 uses an ...

Страница 17: ...d 20 screws Using two 5 8 inch long round head machine screws the 25 Series clamp assembly can be directly attached The cover of the Model 38 does not have to be removed The design of the Model 51 did not allow the inclusion of threaded inserts so holes of adequate size to allow 20 round head machine screws are provided It is intend ed that screws of 5 8 inch length along with lock washers and mac...

Страница 18: ... the tip is from the same source that powers the Model 51 and is provided to power an external preamp If you feel the urge to use this power source be aware that it only provides 110 milliamps of current of which the Model 51 needs about 100mA So go ahead and use all the current you need as long as it doesn t exceed 10mA Note Communications audio from the Model 51 is routed into the Model 50 s cir...

Страница 19: ...s of 600 ohms or greater The Model 70 can be used by itself or in conjunction with up to four Model 35 or Model 38 Talent Amplifiers The loop through connector on the Model 70 can be used to connect to a Model 35 or 38 Talent Amplifier Configuration Many StudioComm functions can be con figured to meet the exact needs of your installation Here s an overview of what you can configure 10dBV or 4dBu l...

Страница 20: ...For convenience Input 7 is located on the front panel of the Model 50 It has a green LED beside it labeled 4 Input Level When lit it tells you that Input 7 is set for 4dBu This means each time you connect a new signal to Input 7 you don t have to go into the configure mode to determine the input sensitivity You should note however that configure settings aren t updated until you leave the con figu...

Страница 21: ...m source or the studio source to follow the headphone source In configure mode the red Studio On LED tells you which function the studio source will follow When the LED is off the studio will follow the control room source when it s on the studio will follow the headphone source Press the Studio On button to toggle the setting Mono Function The Mono function allows the control room output to be pl...

Страница 22: ...is set to mono Press and hold Dub then press CR Studio 2 through 7 to select a dim level LED 2 is Max attenuation approx 72dB LED 3 is 30dB LED 4 is 25dB LED 5 is 20dB LED 6 is 15dB LED 7 is 10dB Press Mono to toggle between latching or momentary operation LED on means the Mono button is set to latch Press Dim to toggle the automatic dim off function LED on means auto dim off function is active Pr...

Страница 23: ... to toggle to 50Hz slate tone LED on means 50Hz tone is on Press and hold Phones Studio then press CR Studio 2 to toggle between normal dub source and dub follows control room source LED on means dub follows control room Press and hold Phones Studio then press CR Studio 3 to configure remote control room source select LED on means function enabled Press and hold Phones Studio then press CR Studio ...

Страница 24: ... alternate configure mode is uti lized By pressing and holding the Level Up button the alternate functions are accessed This is like the ALT key on your personal computer keyboard Talk to Phones Interrupt or Add The talk to phones function can be config ured to either interrupt the source selected for phones audio and connect communi cations audio or to have the communica tions audio added summed ...

Страница 25: ...independently of the control room source When the LED is lit the dub source follows the control room source To make a change you hold Level Up hold the Phones Studio button and press the CR Studio button 2 Remote Control Room Source Select The Remote Control Room Source Select function allows a contact closure to auto matically select input 6 or 7 as the control room source The remote control inpu...

Страница 26: ... output selection is simple To select an input for monitoring in the control room press one of the seven CR Studio buttons The corresponding LED in the CR Studio column will light to let you know which in put is selected If the input is set for mono the LED will continually flash on and off as a warning If the remote control room source select function is enabled the select button associated with ...

Страница 27: ...ays set to latch the function on or off If the headphone source has been con figured to follow the control room source each time one of the CR Studio buttons is pressed the headphone source will fol low You may still independently change the headphone source by pressing the Phones Studio button and pressing one of the seven CR Studio buttons However the headphone source will still follow any chang...

Страница 28: ...use the level control to set the studio output level The button is used to turn the studio output on or off When the LED is off the feed to the studio is off When the LED beside the button is lit the feed to the studio is on Note that the talk to studio communications function is active whether the studio output is on or off As previously discussed when the studio output is on the LED will flash e...

Страница 29: ...rols The power present LED should level to the headphones will be determined by the slate level setting not the talk to phones level The talk to phones function is configured to interrupt or to add to the selected head phone source If interrupt is selected activating talk to phones disconnects the selected headphone source and connects communications audio If add is selected activating talk to pho...

Страница 30: ... control works just like you would guess turn it up for more tal ent signal in the headphone mix and turn it down for less The Talent and Cue Mix level controls work like a mixer for the headphone outputs so you can have any level you want of either source in the headphone mix Troubleshooting If you re having problems getting the StudioComm system up and running this section can help If you haven ...

Страница 31: ...r you ll need a MIDI style cable with all five conductors connected If the Model 51 appears to be at fault it will need to be returned to the factory for repair Input Data LEDs The Model 50 Central Controller s front panel contains two LEDs that represent in coming data The Bus LED lights any time valid MIDI compatible data enters the unit The Model 50 LED lights only when data is received that is...

Страница 32: ...lden 8412 which has 10 9 ohms resis tance per conductor per 1000 feet Since we re using two conductors to carry the signal pins 1 and 2 you d get 21 8 ohms per 1000 feet of microphone cable With our 15 ohm maximum resistance you d be able to use 688 feet 210m of this cable By using the numbers provided you can select a cable and its maximum length for your application Model 50 to Model 51 Cable Le...

Страница 33: ...ry and the Model 50 Central Controller will continue to operate as it did when the link was broken No clicks pops or other noises will occur when the Model 51 is again connected The Model 51 will go through its standard power up sequence send a message to reset power up defaults then send the operating parameters as stored in its memory You may notice a brief inter val of silence while the Model 5...

Страница 34: ... up in the reference voltage Communication Switch Noise During field trials of the StudioComm components one item came up for discussion concerning thumps in the communications functions A brief dis cussion may be useful Electrically the Model 50 and Model 51 electronics that support the communications functions are quite quiet not adding appreciable clicks pops or thumps Software time delays are ...

Страница 35: ...nput sensitivity of the power amplifiers Most power ampli fiers have controls on their inputs to allow easy adjustment of the input sensitivity Control Room and Studio Output Transient Protection Unique to the Model 50 Central Control ler is a power up power down transient protection feature This limits the chance of damage to the control room and stu dio loudspeakers during the time when AC mains...

Страница 36: ...20kHz Talent Amplifier Output Application provides power and audio signals for up to fourModel 35 or Model 38 Talent Amplifiers The output connector 3 pin XLR type male has common on pin 1 23Vdc modulated with left channel audio at 10dBu on pin 2 and right chan nel audio at 10dBu on pin 3 Maximum output current 200mA nominal Dub Output 1 stereo located on both the front and back panels Type electr...

Страница 37: ...with left channel audio provided by Model 50 Central Controller Power Present LED red indicates presence of operating power Connectors Input from Model 50 3 pin XLR type female Loop Thru 3 pin XLR type male connected in parallel with input connector Headphone Outputs 2 inch 3 conductor stereo phone jacks Headphone Output 1 feeds two headphone jacks Load intended for connection to one or two pairs ...

Страница 38: ... 1 Frequency Response 20Hz 20kHz 0 5dB Dimensions Overall 8 0 inches wide 20 3cm 2 0 inches high 5 1cm 5 3 inches deep 13 5cm Mounting Desktop Provision for stand mounting provided Weight 1 5 pounds 0 7kg Model 70 Interface Power Requirements 20 32Vdc modulated with left channel audio provided by Model 50 Central Controller Power Present LED red indicates presence of operating power Connectors Inp...

Страница 39: ...ies Inc manufacturer s ID number is 00H 00H 56H The Model 50 s product device ID number is 01H Note that the 5 pin connector on the Mod el 50 s back panel is wired somewhat dif ferently from a standard MIDI input While pins 4 and 5 meet the MIDI standard the three remaining pins are implemented for use by the Model 51 Pin 1 supplies 15Vdc power pin 2 is shield ground and pin 3 is communications au...

Страница 40: ...tudio output to off 10 Set all input levels to 4 11 Set dub output level to 4 12 Set dim to normal non dim 13 Set dim level to 20dB 14 Set talk to studio to off 15 Set talk to headphones to off 16 Set slate to off Function Input Level Byte Value Description 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Produc...

Страница 41: ...nH Source Selected m range 0 2 0 stereo 1 left only 2 right only n range 0 7 0 no input 1 input 1 2 input 2 etc 8 F7H EOX End of System Exclusive Function Headphone Source Byte Value Description 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Product ID Model 50 6 05H Function Headphone Source 7 mnH Source Sele...

Страница 42: ...ll mute LSB 7F is maximum output MSB 3 places function in reduced precision reverse range mode where LSB 7F is full mute LSB 00 is maximum output Function Studio Level Byte Value Description 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Product ID Model 50 6 08H Function Studio Level 7 0nH Level MSB range 0 3...

Страница 43: ... Left and Right Output A On 2 2 Left and Right Output B On 3 3 Left and Right Outputs A B On 8 F7H EOX End of System Exclusive Function Control Room Mono Stereo Select Byte Value Description 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Product ID Model 50 6 0AH Function Control Room Mono 7 0nH Output Selecte...

Страница 44: ... Value Description 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Product ID Model 50 6 0EH Function Talk to Headphones 7 0nH Status Range 0 2 0 no talk to headphones 1 talk to headphones interrupt 2 talk to headphones add 8 0nH Level range 1 8 8 is loudest 9 F7H EOX End of System Exclusive Function Slate Byte...

Страница 45: ...on 1 F0H System Exclusive Message 2 00H 1st Byte of Studio Tech ID 3 00H 2nd Byte of Studio Tech ID 4 56H 3rd Byte of Studio Tech ID 5 01H Product ID Model 50 6 10H Function Set Dim Level 7 0nH Status Range 0 5 0 full mute approx 70dB 1 30dB dim 2 25dB dim 3 20dB dim 4 15dB dim 5 10dB dim 8 F7H EOX End of System Exclusive ...

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