DBX Silver Series 386 Manual
Contents
1. PRODUCTS INTRODUCTION dbx PROFESSIONAL PRODUCTS Congratulations on your purchase of the dbx 386 Dual Vacuum Tube Preamp with digital out put capabilities For over 25 years dbx has been the industry leader in dynamics processing With the introduction of the 386 we offer the classic smooth and warmth qualities of tube microphone pre amplification combined with the state of the art proprietary dbx Type conversion system to offer the best characteristics of both analog and digital recording capabil ities This manual will be your guide to understanding the full functionality of the powerful 386 After you have become familiar with the unit we encourage you to experiment and find creative ways that the 386 can help you optimize your specific application 0 1 Defining the 386 The dbx 386 Dual Vacuum Tube Preamp provides the user with Dual Vacuum tube microphone preamp capabilities in the analog domain as well as giving you pristine digital output capabil ities Listed below are some of features available to you in the 386 Two channel tube microphone pre amplifier 200V Tube Plate Voltage Insert Jack 60 dB of microphone gain and 15 dB of output gain Selectable mic line switch 48 volt phantom power 20 dB pad 75 Hz low cut filter Phase reverse 12 segment LED analog digital level meter Type IV conversion system Selectable 96 kHz 88 2 kHz 48 kHz or 44 1 kHz sampling2. SERVICING To reduce the risk of fire or electric shock the user should not attempt to service the appliance beyond that described in the operating instructions All other servicing should be referred to qualified service personnel FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTACLE Replace fuse with same type and rating only MULTIPLE INPUT VOLTAGE This equipment may require the use of a different line cord attachment plug or both depending on the available power source at installation Connect this equipment only to the power source indicated on the equipment rear panel To reduce the risk of fire or electric shock refer servicing to qualified service personnel or equivalent RISK OF ELECTRIC SHOCK DO NOT OPEN ATTENTION risque DE CHOC ELECTRIQUE NE PAS OUVRIR WARNING ro REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE The symbols shown above are internationally accepted symbols that warn of potential hazards with electrical products The lightning flash with arrowpoint in an equilateral triangle means that there are dangerous voltages present within the unit The exclamation point in an equilateral triangle indicates that it is necessary for the user to refer to the owner s manual These symbols warn that there are no user serviceable parts inside the unit Do not open the unit Do not attempt to service the unit yourself Refer all servicing to qualified perso
3. Signal Level Figure 1 Converted Level vs Input Level Fig 1 illustrates this concept showing the level of the converted signal below and above the start of the overload region The converted signal level is plotted along the Y axis vertical axis of the plot vs the level of the input signal along the X axis horizontal axis The logarithmic mapping of the overload region begins 4 dB below 0 dB FS full scale of the A D converter What this shows is that below 4 dB FS in the linear region the output signal is the same as the input signal Above this in the logarithmic region high level input signals get mapped into the top 4 dB of the A D con verter This mapping is analogous to the signal compression effect that occurs when recording high level signals onto analog tape d b X PROFESSIONAL PRODUCTS 386 User Manual 21 Input Signal Level TYPE A D Converter Linear Region Figure 2 Input Signal Levels Mapped to Type IV Over Region Noise Floor Fig 2 illustrates the mapping function in a different way Input levels are shown on the left of the graph while con verted levels are shown on the right Notice the mapping of large signal excursions to the 4 dB Type IV Over Region One might question the validity of such an approach trying to represent a lot of signal information within a smaller space The reason why this is not only valid but makes a whole lot of sense is that the digital codes
4. 2008 Pad and Phase functions are only available when the microphone input is in use Low Cut Switch This switch places a 12 dB per octave shelving high pass filter in the signal path The knee frequency of the Low Cut filter is 75 Hz This filter is very useful for removing low frequency rumble or handling noise from a microphone input signal Analog Output This knob controls the overall level of the analog output signal and ranges from 15 to d b X PROFESSIONAL PRODUCTS 386 User Manual Meter Select Switch This switch allows you to select display metering of either the digital or analog output signal The analog level is scaled in dBu while the digital level is scaled in dBFS LightPipe Meter This meter displays either the analog or digital output signal Digital Output This knob controls the signal being sent to the A D Converter and ranges from 15 to 1 3 Front Panel Type IV conversion system controls dbx TYPE IV CONVERSION SYSTEM Y 96 kHz R SNR R Shape2 2 R 24 R S PDIF G TPDF G Shape1 2 G 20 G AES EBU Off None Off None Off 44 1 kHz Off 16 DITHER SHAPE SAMPLE WORD OUTPUT RATE LENGTH FORMAT Oooo C3 Dither Switch This switch is used to select the dither type algorithms including TPDE SNR2 or None Dither is random noise that is added to the audio signal which effectively eliminates the harmonic dis tortion c
5. 8760 South Sandy Parkway Sandy Utah 84070 USA 801 568 7638 801 568 7642 LITHIUM BATTERY WARNING CAUTION This product may contain a lithium batter y T here is danger of explosion if the battery is incorrectly replaced Replace only with an Eveready CR 2032 or equivalent Make sure the bat tery is installed with the correct polarity Discard used batter ies according to manufacturer s instructions ADVARSEL Lithiumbatteri Eksplosjonsfare Ved utskifting benyttes kun batteri som anbefalt av apparatfabrikanten Brukt batteri returneres apparatleverandgren ADVARSEL Lithiumbatteri Eksplosionsfare ved fejlagtig h ndtering dskiftning m kun ske med batteri av samme fabrikat og type Lev r det brugte batteri tilbage til leverandgren VAROITUS Paristo voi r j ht jos se on virheellisesti asennettu Vaihda paristo ainoastaan laitevalmistajan suosittelemaan tyyppin H avita k ytetty paristo valmistajan ohjeiden mukaisesti VARNING Explosionsfara vid felaktigt batteribyte Anv nd samma batteri typ eller en ekvivalent typ som rekommenderas av apparattil Kassera anv nt batteri enligt fabrikantens instruk tion ELECTROMAGNETIC COMPATIBILITY This unit conforms to the Product Specifications noted on the Declaration of Conformity Operation is subject to the following two condi tions e this device may not cause harmful inter ference and e this device must accept any i
6. In and Out Connectors BNC connectors are provided for both clock in and out functions The 386 s clock chips are dbx custom VCXO chips designed for low jitter performance You may use the 386 as a master clock source having other equipment slave to the 386 or you may slave the 386 s clock to any other wordclock source device Analog Input Connectors The analog input section of the 386 offers both XLR Microphone and a rear 1 4 TRS Line electronically balanced connections The 1 4 connector may be used in a balanced or unbal anced configuration Using a 1 4 TS connector will unbalance the signal Analog Output Connectors The analog output section of the 386 offers both XLR and 1 4 TRS electronically balanced con nections The 1 4 connector may be used in a balanced or unbalanced configuration Using a 1 4 TS connector will unbalance the signal Insert Jack The 1 4 TRS Insert jack Tip SEND and Ring RETURN will allow you to add an effects loop directly into the signal path of the 386 This insertion point is located after the tube section and prior to the output section This insertion positioning is ideal for adding external effects such as a compressor or an EQ to the analog and digital output sections 2 386 User Manual d b X PROFESSIONAL PRODUCTS 1 2 Front Panel Controls Dual Vacuum 3 XC w Digital Out 5 2 5 8 5 2 2 2 2 8 gig ANALO
7. below which extends to the first end user After expiration of the warranty a reasonable charge will be made for parts labor and packing if you choose to use the factory service facility In all cases you are responsible for transportation charges to the fac tory dbx will pay return shipping if the unit is still under warranty Use the original packing material if it is available Mark the package with the name of the ship per and with these words in red DELICATE INSTRUMENT FRAGILE Insure the package prop erly Ship prepaid not collect Do not ship parcel post 0 3Warranty This warranty is valid only for the original purchaser and only in the United States 1 The warranty registration card that accompanies this product must be mailed within 30 days after purchase date to validate this warranty Proof of purchase is considered to be the bur den of the consumer 2 dbx warrants this product when bought and used solely within the U S to be free from defects in materials and workmanship under normal use and service 3 dbx liability under this warranty is limited to repairing or at our discretion replacing defec tive materials that show evidence of defect provided the product is returned to dbx WITH RETURN AUTHORIZATION from the factory where all parts and labor will be covered up to a period of two years A Return Authorization number must be obtained from dbx by telephone The company shall not be liable for any consequen
8. in the unit or in the system to which it is connected can result in full line voltage between chassis and earth ground Severe injury or death can then result if the chassis and earth ground are touched simultaneously IMPORTANT SAFETY INSTRUCTIONS U K MAINS PLUG WARNING molded mains plug that has been cut off from the cord is unsafe Discard the mains plug at a suitable disposal facility NEVER UNDER ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT MAINS PLUG INTO A 13 AMP POWER SOCKET Do not use the mains plug without the fuse cover in place Replacement fuse covers can be obtained from your local retailer Replacement fuses are 13 amps and MUST be ASTA approved to BS1362 DECLARATION OF CONFORMITY Manufacturer s Name Manufacturer s Address dbx Professional Products 8760 S Sandy Parkway Sandy Utah 84070 USA declares that the product Product name dbx 386 Product option N A conforms to the following Product Specifications EMC EN 55013 1990 EN 55020 1991 Supplementary Information The product herewith complies with the require ments of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC as amended by Directive 93 68 EEC dbx Professional Products Vice President of Engineering 8760 S Sandy Parkway Sandy Utah 84070 USA December 15 1999 European Contact Your Local dbx Sales and Service Office or Harman Music Group
9. rate 24 20 and 16 bit wordlengths Selectable dither and noise shaping AES EBU and S PDIF digital outputs Word clock sync input and output Separate analog and digital output control With the dbx proprietary patent pending TSE Tape Saturation Emulation and TYPE Conversion System your signal retains its analog warmth and character with the pristine clari ty demanded by today s digital standards In addition the 386 offers 96kHz A D conversion which results in improved frequency response i 386 User Manual d b X PROFESSIONAL PRODUCTS 0 2 Service Contact Info If you require technical support contact dbx Customer Service Be prepared to accurately describe the problem Know the serial numberof your unit this is printed on a sticker attached to the rear panel If you have not already taken the time to fill out your warranty registration card and send it in please do so now Before you return a product to the factory for service we recommend you refer to the manu al Make sure you have correctly followed installation steps and operation procedures If you are still unable to solve a problem contact our Customer Service Department at 801 568 7660 for consultation If you need to return a product to the factory for service you MUST contact Customer Service to obtain a Retum Authorization Number No returned products will be accepted at the factory without a Retum Authorization Number Please refer to the warranty
10. that you are not sending two sources of 48V phantom power to the mic Use the 48V from the mic s power supply Use the 48V Phantom Power switch on the 386 for all other microphones which require phantom power 2 Set the front panel of the 386 to the desired settings including phantom power 20 dB pad phase etc Connect the line output of the 386 to the console s LINE INPUT and ensure that the console s input selection switch is set to LINE and the console s gain control is set appropriately low 3 Tum the 386 s DRIVE control to the minimum position Tum the OUTPUT LEVEL control to the 12 o clock position and apply power to the 386 Make sure your console s gain fader is at the nominal level and begin to slowly increase the gain of the 386 using the DRIVE control You should increase the gain until the mixing recording device is operating at nom inal signal input level 6 386 User Manua d b X PROFESSIONAL PRODUCTS 2 3 Direct Connection to a Recorder 1 Make microphone connections being careful to keep the DRIVE control in the minimum 30 dB position 2 Connect the 386 s Line outputs directly to the audio inputs of your recorder 3 Enable the record function of the specific track of the recorder and open the specific tape track return in the console which corresponds to the track to which the 386 is connected As you increase the setting of the DRIVE control you should begin to hear the input of the 386 running throug
11. the 386 and run into the AES EBU or S PDIF input interface of the DAW CPU Front Panel Digital Output Features 1 Use the METER switch to select digital output metering 2 Use the DITHER switch to select the desired dither algorithm 3 Use the SHAPE switch to select the desired noise shaping algorithm 4 Use the SAMPLE RATE switch to select the correct sampling rate 5 Use the WORD LENGTH switch to select the correct word length 6 Use the OUTPUT FORMAT switch to select the appropriate digital output format 14 386 User Manual d b X PROFESSIONAL PRODUCTS 3 7 Multi Tracking to Digital Rear Panel Connections Connect the source to the desired 1 4 TRS or XIR input jack Connect the AES EBU or S PDIF output of the 386 and run into the AES EBU or S PDIF input of the digital mixer Front Panel Digital Output Features 1 Use the METER switch to select digital output metering 2 Use the DITHER switch to select the desired dither algorithm 3 Use the SHAPE switch to select the desired noise shaping algorithm 4 Use the SAMPLE RATE switch to select the correct sampling rate 5 Use the WORD LENGTH switch to select the correct word length 6 Use the OUTPUT FORMAT switch to select the appropriate digital output format d b X PROFESSIONAL PRODUCTS 386 User Manual 15 3 8 Analog and Digital O utput Application 111 1111111111 N im The 386 gives you the unique option of utilizing t
12. 48 kHz RED for 88 2 kHz and YELLOW for 96 kHz Word Length Switch Selects output wordlength of 16 20 or 24 bits output resolution The LED will not be lit for 16 bit GREEN for 20 bit and RED for 24 bit Output Format Selects either the AES EBU or S PDIF digital output format The LED will be red for AES EBU and green for S PDIF 3 2 Digital Output Rear Panel Connections PROFESSIONAL PRODUCTS A HARMAN INTERNATIONAL 1 COMPANY SALT LAKE CITY UTAH MADE IN USA MODEL 386 SIPDIF DUAL VACUUM TUBE PREAMP Cp WITH DIGITAL OUT AES EBU WORD CLOCK 10 386 User Manual d b X PROFESSIONAL PRODUCTS AES EBU Digital The 386 provides A ES EBU digital output formating through the XLR connector Be sure to use short lengths of 1100 digital cables rather than standard XLR to XLR cables U sing the correct cables will pre vent digital dropouts and other interconnection problems S PDIF Digital Connector The 386 provides S PDIF digital output formating through the RCA coaxial connector Be sure to use short lengths of 750 digital cables or 75 video cables rather than standard audio RCA to RCA cables U sing the correct cables will prevent digital dropouts and other interconnection problems NOTE Although digital information is coming out of both XLR and RCA jacks simultaneously the correct format will only appear at the output for the format type selected For example if you have A ES EBU format sele
13. G OUTPUT LEVEL sav 208 2 OOOO es 9 27 2 2 5 6 5 85 0 PROFESSIONAL PRODUCTS AD PHASE LOWCUT Instrument Input This unbalanced high impedance input connection is used to insert an instrument signal direct ly into the preamp Use the LINE switch to make instrument input or the rear panel line input active Plugging into the instrument jack will override the rear panel 1 4 input jack line input must be selected Line Select Switch This switch when lit selects the rear line input or front panel instrument input when some thing is connected as the source signal of the 386 Drive Control This control sets the amount of gain at the input of the vacuum tube stage The range of gain available is 0 to 460 dB 15 to 15 dB when LINE INPUT is selected Peak LED This LED will light 3dB prior to input stage clipping 448 Volt Switch This switch activates phantom power for condenser microphones on pins 2 and 3 of the XLR mic input You should connect your microphone before turning on the phantom power to pre vent damage to your microphone Be sure to always lower levels prior to using the the 8 Volt Switch 20db Pad Switch This switch attenuates the microphone input signal by 20dB Phase Switch This switch inverts the phase of the incoming signal at the Mic input by swapping pins 2 and 3 on the XLR connector Note The 48 Volt
14. P PN ude 6ueg Lr Co sindino Boruy uus 23722 mano pom ajdues E11 3E TEF NO go Neo Slwyeun Block Diagram Type IV White Paper dbx Type IV Conversion System W hite Paper by Roger Johnson The dbx Type IV Conversion System is a proprietary analog to digital A D conversion process that combines the best attributes of digital conversion and analog recording processes to preserve the essence of the analog signal when it is converted to a digital format dbx Type IV not only exploits the wide linear dynamic range of today s A D con verters but also enhances it and extends the useable dynamic range beyond the linear range By providing a logarith mic Type IV Over Region above the linear A D range we benefit from the extended high level headroom that is inherent in analog recording without compromising the noise performance of the A D conversion process Digital conversion and recording processes proliferated in the 1980 s primarily due to the cleaner sound of dig ital versus analog an advantage resulting from the comparatively wider linear dynamic range of digital Anyone who is familiar with the technical specifications of digital equipment knows that the typical maximum signal to noise specifica tions for 16 bit systems is in the neighborhood of 90 something dB Compare this to the typical signal to noi
15. S EBU or S PDIF input interface of the DAW CPU Front Panel Digital Output Features 1 Use the METER switch to select digital output metering 2 Use the DITHER switch to select the desired dither algorithm 3 Use the SHAPE switch to select the desired noise shaping algorithm 4 Use the SAMPLE RATE switch to select the correct sampling rate 5 Use the WORD LENGTH switch to select the correct word length 6 Use the OUTPUT FORMAT switch to select the appropriate digital output format 12 386 User Manual d b X PROFESSIONAL PRODUCTS 3 5 Direct Connection to a Digital Mixer Rear Panel Connections Connect the source to the desired 1 4 TRS or XLR input jack Connect the AES EBU or S PDIF output of the 386 and run into the AES EBU or S PDIF input of the digital mixer Front Panel Digital Output Features 1 Use the METER switch to select digital output metering 2 Use the DITHER switch to select the desired dither algorithm 3 Use the SHAPE switch to select the desired noise shaping algorithm 4 Use the SAMPLE RATE switch to select the correct sampling rate 5 Use the WORD LENGTH switch to select the correct word length 6 Use the OUTPUT FORMAT switch to select the appropriate digital output format d b X PROFESSIONAL PRODUCTS 386 User Manual 13 3 6 A D Conversion Rear Panel Connections Connect the source to the desired 1 4 TRS or XLR input Connect the AES EBU or S PDIF output of
16. ce Digital Outputs Connectors Impedance Word Sync Input Output Connectors Input Impedance Input Output System Performance DRIVE Control Range LEVEL Control Range Analog and Digital LINE Phantom Power PAD PHASE LOW CUT Analog Frequency Response THD Noise Interchannel Crosstalk Analog to Digital Conversion ype Sample Rate Wordlength Dither Type Noise Shape Output Format Convertor Dynamic Range Power Su Operating Supply Power Requirements Physical Weight Dimensions NOTE 0dBu 18dBFS OdBu 0 775 5 26 386 User Manual d b X PROFESSIONAL PRODUCTS dbx PROFESSIONAL PRODUCTS H A Harman International Company 8760 South Sandy Pkwy Sandy Utah 84070 Phone 801 568 7660 Fax 801 568 7662 Int l Fax 603 672 4246 Questions or comments E email us at customer dbxpro com or visit our World W ide Web home page at www dbxpro com 18 0098 A
17. closure the unit should be positioned with enough room atleastone centimeter at the top and one centimeteratthe bottom ofthe unit to allow proper ventilation The 386 should not be mounted above or below anything that generates excessive heat Ambient temperatures should not exceed 113 F 45 C when equipment is in use Although the unit is shielded against radio frequency and electromagnetic interference extremely high fields of RF and EMI should be avoided where possible Make audio connections via XLR 1 4 TRS or 1 4 TS plugs With the flexibility of the 386 various connection options are available Forinput con nection use the XLR Microphone 1 4 line or 1 4 instrument front panel inputs For analog output connections use either XLR or 1 4 Line output The use of more than one connector at a time for the output section could unbalance balanced lines cause phase cancellations short a conductor to ground or cause damage to other equipment connected to the 386 Apply powerto the 386 Connectthe AC power cord to the AC power receptacle on the back of the unit Route the AC power cord to a convenient power outlet away from audio lines The unit may be turned on and off from the rear panel power switch or from a master equip ment power switch 2 2 Connection to a Mixing Console 1 Connect your mic cable to the Mic input of the 386 NOTE If you are using a mic with a separate power supply such as a tube microphone make sure
18. cted an A ES EBU formatted signal will appear at the output of both the XLR and the RCA connector Or if you haveS PDIF format selected an S PDIF formatted signal will appear at the output of both the RCA and XLR connectors Sync In and Out Connectors BNC connectors are provided for both word clock in and out functions The 386 s clock chips are dbx custom VCXO chips designed for low jitter performance You may use the 386 as a master clock source having other equipment slave to the 386 or you may slave the 386 s clock to any other word clock source 3 3 Sync Input Sample Rate Selection When connecting an incoming or master device to the sync input of the 386 the 386 will auto matically lock to the sample rate of the master device The sample rate will then be indicated in the SAMPLE RATE select button dbx TYPE IV CONVERSION SYSTEM Y 96 kHz R Shape 2 2 R 24 R S PDIF G TPDF hape 1 G 48 kHz G 20 G AES EBU Off None Off Off 44 1 kHz Off 16 DITHER SH SAMPLE WORD OUTPUT RATE LENGTH FORMAT OOOO oO Note that when the master device is disconnected from the Sync Input connection the SAMPLE RATE select button will flash until an internal sample rate is selected d b X PROFESSIONAL PRODUCTS 386 User Manual 11 3 4 Direct Connection to a DAW CPU Rear Panel Connections Connect the source to the desired 1 4 TRS or XLR input Connect the AES EBU or S PDIF output of the 386 and run into the AE
19. db X TS IMPORTANT SAFETY INSTRUCTIONS WARNING FOR YOUR PROTECTION PLEASE READ THE FOLLOWING KEEP THESE INSTRUCTIONS HEED ALL WARNINGS FOLLOW ALL INSTRUCTIONS CLEAN ONLY WITH A DAMP CLOTH DO NOT BLOCK ANY OF THE VENTILATION OPENINGS INSTALL IN ACCORDANCE WITH THE MANUFACTURERS INSTRUCTIONS DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS HEAT REGISTERS STOVES OR OTHER APPARATUS INCLUDING AMPLIFIERS THAT PRODUCE HEAT ONLY USE ATTACHMENTS ACCESSORIES SPECIFIED BY THE MAN UFACTURER UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG PERIODS OF TIME WATER AND MOISTURE Appliance should not be used near water e g near a bathtub washbowl kitchen sink laundry tub in a wet basement or near a swimming pool etc Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through openings POWER SOURCES The appliance should be connected to a power supply only of the type described in the operating instructions or as marked on the appliance GROUNDING OR POLARIZATION Precautions should be taken so that the grounding or polarization means of an appliance is not defeated POWER CORD PROTECTION Power supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them paying particular attention to cords at plugs convenience receptacles and the point where they exit from the appliance
20. eci tic N mp cla i mr PE dbx PROFESSIONAL PRODUCTS i A T CHANNEL TWO CHANNEL ONE r r mic LINE OUTPUTS INPUTS LINE OUTPUTS INPUTS 1001 ro 50 60H IN OUT K Power Switch Turns the 386 on and off IEC Power Cord Receptacle This is the power cord receptacle of the 386 An IEC cord is included with the shipped prod uct AES EBU Digital Connector The 386 provides A ES EBU digital output formating through the XLR connector Be sure to use short lengths of 11042 digital cables rather than standard XLR to XLR cables Usingthe correct cables will prevent digital dropouts and other interconnection problems S PDIF Digital Connector The 386 provides S PDIF digital output formating through the RCA coaxial connector Be sure to use short lengths of 750 digital cables or 75Q video cables rather than standard audio RCA to RCA cables U sing the correct cables will prevent digital dropouts and other interconnection problems NOTE Although digital information is coming out of both XLR and RCA jacks simultaneously the correct format will only appear at the output for the format type selected For example if you have AES EBU format selected an AES EBU formatted signal will appear at the output of both the XLR and the RCA connector Or if you have S PDIF format selected an S PDIF formatted signal will appear at the output of both the RCA and XLR connectors Sync
21. h the recorder and returning to your console as a tape return d b X PROFESSIONAL PRODUCTS 386 User Manual 7 8 pal Pi dbx PROFESSIONAL PRODUCTS 3 1 Digital Output Front Functions of the 386 dbx TYPE IV CONVERSION SYSTEM Y 96 kHz R SNR R Shape2 2 R 24 R S PDIF G TPDF G Shape1 7 G 20 G AES EBU Off None Off None Off 44 1 kHz Off 16 DITHER SHAPE SAMPLE WORD OUTPUT RATE LENGTH FORMAT OOOO Dither Switch This switch is used to select the dither type algorithms including TPDE SNR or None Dither is random noise that is added to the audio signal which effectively eliminates the harmonic distor tion created by truncation See the Truncation graph in section D 2 of the Appendix The LED will be lit RED for the SNR2 or GREEN for the TPDF dither algorithm When the LED is off dither ing is not in use Shape Switch This switch selects the Shape 1 or Shape 2 psycho acoustic noise shaping curve Shape 1 uti lizes a mild psycho acoustic curve while the curve used in Shape 2 tends to be more aggres sive Please see the Noise Shaping graph in section D 1 of the appendix The LED will be lit GREEN for Shape 1 and RED for Shape 2 When the LED is off the noise shaping algorithm is not in use Sample Rate Switch This switch selects the digital output sample rate of either 44 1 48 88 2 or 96 kHz The LED will not be lit for 44 1 kHz GREEN for
22. he analog and digital outputs simultaneously This option is ideal for using the analog output section as a reference monitoring signal of the dig ital signal Both analog and digital outputs offer independent output control which allows you to send a digital signal to a receiving device such as a DAW or digital recorder and route the ana log signal to a monitoring device such as a mixer or headphone amplifier while controlling both levels independently all at the same time Rear Panel Connections Connect the source to the desired 1 4 TRS or XIR input Connect the AES EBU or S PDIF output of the 386 and run into the AES EBU or S PDIF input interface of the DAW CPU Connect the 1 4 TRS or XLR output of the 386 and run into the 1 4 TRS or XIR input of the monitoring device Front Panel Digital Output Features 1 Use the METER switch to select digital output metering 2 Use the DITHER switch to select the desired dither algorithm 3 Use the SHAPE switch to select the desired noise shaping algorithm 4 Use the SAMPLE RATE switch to select the correct sampling rate 5 Use the WORD LENGTH switch to select the correct word length 6 Use the OUTPUT FORMAT switch to select the appropriate digital output format 16 386 User Manual d b X PROFESSIONAL PRODUCTS dbx PROFESSIONAL PRODUCTS Sync Input Info The dbx 386 comes with the word input 759 terminated For certain configurations yo
23. in 2 Hot and TRS 1 4 Servo balanced unbalanced Balanced 12042 unbalanced 60Q gt 21 dBu 2420 dBm into a 600Q load TRS 1 4 Unbalanced 1000 SEND 20kQ RETURN XLR for AES EBU RCA for S PDIF 110Q for AES EBU 750 for S PDIF BNC 752 terminated by internal jumper 96 88 2 48 or 44 1kHz word clock 96 88 2 48 or 44 1kHz word clock 30dB to 60dB for Mic Input 15dB to 15dB for Line and Instrument Inputs 15dB to 15dB Selects between microphone and line inputs 48V 20dB pad EIE pins 2 and 3 of the microphone input XLR 75Hz 12dB octave high pass filter 10Hz to 75kHz 0 35 typical at 4dBu out 1kHz 40 dB gain Typically 80dB 20Hz to 20kHz dbx Type IV A D Conversion System 96 88 2 48 or 44 1kHz selectable 24 20 or 16 bit selectable TPDE SNR or none Shape 1 Shape 2 or none S PDIF or AES EBU 107dB typical A weighted 22kHz bandwidth DO 120VAC 60Hz 100VAC 50 60Hz EU 230VAC 50 60 Hz 35 Watts 7 3 lbs 3 3kg 1 75 x 7 75 x 19 4 5cm x 19 7cm x 48 5cm D 3 Specifications Microphone Input Connector Type Impedance Maximum Input Level Equivalent Input Noise Line Input Rear Panel Connector Type Impedance Maximum Input Level CMRR Gain Drive Control Instrument Input Front Panel Connector Type Impedance Maximum Input Level Analog Outputs Connector Type Impedance Maximum Output Level Insert Connector Type Impedan
24. in a con verter are linear or evenly spaced meaning that each consecutive code represents the same change in voltage of the input signal This implies that half of the digital codes are used to represent input signals whose voltage level is below 1 2 of the full scale A D input voltage while the other half of the codes are used to represent signals above 1 2 of the full scale A D input voltage This seems reasonable until you realize that 1 2 of the full scale input is only 6 dB below full scale So half of the codes are used to represent only the top 6 dB of signal information while the other half are used to represent the remaining 80 to 110 dB of signal information depending on the quality of the converter It seems not only reasonable but also desirable to utilize the increased signal resolution afforded by this density of digital codes to represent more input dynamic range in this region Another advantage of the logarithmic mapping of our dbx Type IV Conversion System is that it preserves the high frequency detail of the signal in the overload region Figs 3a through 3d illustrate what happens when you over load an A D converter without Type IV Fig 3a shows an input signal having both low frequency and high frequen cy components When the signal overloads or clips Fig 3b at the A D converter a disproportionate amount of high frequency signal information is lost compared with the low frequency information The low and high frequenc
25. nnel Opening the chassis for any reason will void the manufacturer s warranty Do not get the unit wet If liquid is spilled on the unit shut it off immediately and take it to a dealer for service Disconnect the unit during storms to prevent damage SAFETY INSTRUCTIONS NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD WARNING THIS APPLIANCE MUST BE EARTHED The cores in the mains lead are coloured in accordance with the following code GREEN and YELLOW Earth BLUE Neutral BROWN Live As colours of the cores in the mains lead of this appliance may not correspond with the coloured markings identifying the terminals in your plug proceed as follows The core which is coloured green and yellow must be connected to the ter minal in the plug marked with the letter E or with the earth symbol or coloured green or green and yellow The core which is coloured blue must be connected to the terminal marked N or coloured black The core which is coloured brown must be connected to the terminal marked L or coloured red This equipment may require the use of a different line cord attachment plug or both depending on the available power source at installation If the attachment plug needs to be changed refer servicing to qualified service personnel who should refer to the table below The green yellow wire shall be connected direct ly to the units chassis WARNING If the ground is defeated certain fault conditions
26. nterference received including interference that may cause undesired operation Operation of this unit within significant electro magnetic fields should be avoided Introduction Section 3 Digital Applications 0 1 Defining 16 1 3 1 Digital Output Front Panel Functions 10 0 2 Service Contact Info ii 3 2 Digital Rear Panel Connections 10 0 3 Warranty ses VE D eR n ii 3 3 Sync Input Sample Rate Selection 11 0 4 Installation Recommendations ii 3 4 Direct Connection to a DAW CPU 12 3 5 Direct Connection to a Digital Mixer 13 Section 1 Getting Started 3 6 A D CONVERSION ssa ada 14 1 1 Rear Panel Connections sss 2 3 7 Multi Tracking to Digital 15 1 2 Front Panel Connections 3 3 8 Analog and Digital Output Applications 16 1 3 Type IV Conversion System Controls 4 Appendix Section 2 Analog Applications Syne Input 1 1 anna 18 2 1 Basic Connection eee 6 m Block AAA rs 19 2 2 Connection to a Mixing Console 6 dbx Type IV Conversion System 20 2 3 Direct Connection to a Recorder 7 D 1 Noise Shaping Algorithms 25 D2 Inincalion 1 1 1 11 25 D 3 606066606666666 666666666666660 26 Table of Contents
27. ous encode decode process of Type 111 similarly expands the limited dynamic range through minimum delay devices Type IV breaks new ground by greatly enhancing the useable dynam ic range of the analog to digital conversion process The dbx Type IV Conversion System combines proprietary analog and digital processing techniques to cap ture a much wider dynamic range than the A D converter could by itself preserving the maximum amount of informa tion from the analog signal This information is then encoded within the available bits of whichever A D converter is used This means that Type IV improves the performance of any A D converter from low cost 16 bit to high perfor mance 24 bit And no decoding is necessary beyond the conversion process As we have previously mentioned digital systems have a wide linear region compared to analog tape and the dynamic range of A D converters has improved significantly in recent years The dbx Type IV Conversion System takes advantage of this and utilizes the top 4 dB of the A D converter s linear dynamic range to create a logarithmic overload region This allows high level transient signals passing far above the point where the overload region begins to be ade quately represented in just 4 dB of the converter s dynamic range whereas a typical A D converter would clip With Type IV you can never clip the A D converter Converted Signal Level dB FS A D Clip Point 4 0 4 8 12 Input
28. probably wondering What s the catch I can t get something for nothing so what did I give up You may be worried that your A D noise floor got 4 dB worse because we borrowed the top 4 dB of your converter This is certainly a valid concern Fortunately we have the answer Without going into the confidential technical details by using our proprietary analog and digital Type IV processing we reclaim the original A D noise level So what you get is free headroom The benefits of the dbx Type IV Conversion System can easily be heard by switching it in and out while lis tening to signals with high level peaks captured in the Type IV Over Region You will notice an obvious audible dif ference With Type IV bypassed you can t help notice the harsh edgy sound of the A D converter clipping With Type IV enabled those nasty artifacts disappear revealing a more open and natural sound With Type IV enabled you will get a more accurate and pure representation of the original wide dynamic range signal You will absolutely agree that we really do give you something for nothing We give you peace of mind knowing that you never have to worry about clipping your A D again And when you listen to the noise floor of your A D you ll realize that we never compromise your noise performance with Type IV The dbx Type IV Conversion System succeeds in combining the best of the analog and digital worlds to cap ture the truest essence and fulle
29. reated by truncation See the Truncation graph in section D 2 of the Appendix The LED will be lit RED for the SNR2 or GREEN for the TPDF dither algorithm When the LED is off dithering is not in use Shape Switch This switch selects either the Shape 1 or Shape 2 psycho acoustic noise shaping curve Shape 1 utilizes a mild psycho acoustic curve while the curve used in Shape 2 tends to be more aggressive Please see the Noise Shaping graph in section D 1 of the Appendix The LED will light GREEN for Shape 1 and RED for Shape 2 When the LED is off the noise shaping effect is not in use Sample Rate Switch This switch selects the digital output sample rate of either 44 1 48 88 2 or 96 kHz The LED will not be lit for 44 1 kHz GREEN for 48 kHz RED for 88 2 kHz and YELLOW for 96 kHz Word Length Switch Selects output wordlength of 16 20 or 24 bits output resolution The LED will not be lit for 16 bit GREEN for 20 bit and RED for 24 bit Output Format Selects the AES EBU or S PDIF digital output format The LED will be lit red for AES EBU and green for S PDIF 4 386 User Manual d b X PROFESSIONAL PRODUCTS n I 8 N f I Vul dbx PROFESSIONAL PRODUCTS 2 1 Basic Analog Connection of the 386 Turn off all equipment before making any connections Install the 386 in your rack with the provided rack screws It is essential that when the 386 is being mounted in a rack mounting en
30. se specifi cations for professional analog tape of about 55 dB without the aid of noise reduction and around 75 to 85 dB with noise reduction such as dbx Type I or Type II applied This seemingly tremendous signal to noise advantage of digital over analog would suggest that digital would become the unanimous choice for recording For the most part this has occurred not totally due to its signal to noise advantage but as much due to the benefits of digital storage such as random access and the inherent ability to with stand degradation unlike that of analog tape or LP s In spite of the benefits of digital no one in the audio world can refute the rediscovery of analog recording and tube gear that has occurred in the 90 s attributable to the quest for that analog character that is missing from digital recordings This continued use of analog gear with modern digital systems brings to light a favorable characteristic of analog recording which those who abandoned analog and jumped on the dig ital bandwagon were either never aware of or simply took for granted Anyone who has ever used analog tape knows that you can hit it hard without destroying the recording The printed specifications of analog tape don t take into account the practical headroom available The max signal to noise specification of analog tape is measured by defining the max signal as the point where a given signal level and fre quency produces a given percent Total Harmonic Dis
31. st dynamic range of audio signals Who else but dbx would bring you this technology 24 386 User Manual d b X PROFESSIONAL PRODUCTS D 1 Noise Shaping Algorithm Hoise Shaping Audio Precision FFT SPECTRUM ANALYSIS DIGITAL 06 05 99 23 20 36 ge D Ap 20 20 4 8 8 an B 2n m E nu n E En de E EN iii iia Hi th 8 1 16 811 TPDF dither a Shape off b with shape set to S1 c with shape set to S2 Parameters Input 60dBFS 1 kHz FFT Length 2048 Sample Rate 48 Khz Averages 32 Graph Steps 1024 D 2Truncation Truncation Audio Precision FFT SPECTRUM ANALYSIS DIGITAL 050506 23 35 36 i n Ap B 00 10 10 8 PE I i ELIT Bese aes I T An Am ds AB 0 7 di ER BH zi 1k EL TER TER oak Pig 2 a 24 511 word b 16 811 truncated output no dither Parameters Input 60dBFS 1 kHz FFT Length 2048 6 Rate 48 Khz Averages 32 Graph Steps 1024 d b X PROFESSIONAL PRODUCTS 386 User Manual 25 Female XLR Pin 2 Hot F ecmoni ally balanced unbalanced Q 9 dBu or 11 dBu with 20 dB pad engaged gt 40dB Typically 55dB Typically 120 dBu with a 1500 source load 20Hz to 20kHz BW TRS 1 4 Jack Electronically balanced unbalanced 20kQ unbalanced 40kQ balanced 21dBu balanced or unbalanced gt 40dB Typically 55dB 15dB to 15dB TS 1 4 Jack Unbalanced 470 kQ 21dBu unbalanced Male XLR P
32. sty side effects such as going unstable when their modulator is overdriven with high level signals This shortcoming of digital conversion has drastically affected the way users operate their equipment Users are paranoid of overdriving the converter input and end up recording at lower levels to ensure that there is ample head room to allow for the large peaks that would ruin an otherwise perfect recording This of course compromises signal 20 386 User Manual d b X PROFESSIONAL PRODUCTS to noise performance since the signal is now closer to the noise floor Because users of digital equipment have to be extremely careful not to exceed 0 dB FS full scale they must use peak reading headroom meters On the other hand the forgiving nature of analog tape allows users of analog recording equipment the luxury of only needing to monitor the average level using VU meters often having no peak indicators whatsoever If only digital were more forgiving like analog we could really exploit its wide dynamic range and more completely capture the essence of the musical perfor mance Enter the dbx Type IV Conversion System Like its related predecessor technologies Type I Type 11 and Type III dbx Type IV succeeds in preserving the wide dynamic range of the original analog signal within a limit ed dynamic range medium Whereas Type I and Type 11 expand the dynamic range of analog tape and other limit ed dynamic range media and the simultane
33. tial damage as a result of the product s use in any circuit or assembly 4 dbx reserves the right to make changes in design or make additions to or improvements upon this product without incurring any obligation to install the same additions or improvements on products previously manufactured 5 The foregoing is in lieu of all other warranties expressed or implied and dbx neither assumes nor authorizes any person to assume on its behalf any obligation or liability in con nection with the sale of this product In no event shall dbx or its dealers be liable for spe cial or consequential damages or from any delay in the performance of this warranty due to causes beyond their control d b X PROFESSIONAL PRODUCTS 386 User Manual ii 0 4 Installation Recommendations Install the 386 in your rack with the provided rack screws It is essential that when the 386 is being mounted in a rack mounting enclosure the unit should be positioned with enough room atleast one centimeter at the top and one centimeter at the bottom of the unit to allow prop er ventilation The 386 should not be mounted above or below anything that generates exces sive heat Ambient temperatures should not exceed 113 F 45 C when equipment is in use Although the unitis shielded against radio frequency and electromagnetic interference extreme ly high fields of RF and EMI should be avoided where possible iii 386 User Manual d b X PROFESSIONAL PRODUCTS S
34. tortion THD typically the level at which a 1 kHz signal produces 396 THD In actual use the signal can easily exceed this max signal level by 5 10 or even 15 dB on peaks depend ing on the type of signal being recorded without unacceptable artifacts High signal levels can be tolerated i e more headroom at the expense of increased THD which incidentally is often desirable as an effect evidenced by the renewed popularity of tube equipment The obvious conclusion is that analog recording actually has more useable dynamic range than the specifica tions seem to indicate For example let s say we re recording a kick drum If analog tape measures 55 dB from the 396 THD point down to the RMS noise floor and the peaks of the kick drum exceed the 396 THD level by say 15 dB and it still sounds good then we have 15 dB of extra useable headroom Therefore we end up with 70 dB of useable dynam ic range Throw in noise reduction and we push into the 90 something dB dynamic range territory of 16 bit digital This explains why well recorded analog master tapes make good sounding CD s with no objectionable noise One main drawback of digital is that it inherently lacks this forgiving and beneficial characteristic of analog recording Although digital conversion exhibits wide linear dynamic range when you run out of headroom for high level signals hard clipping or even ugly signal wrap around occurs not to mention that A D converters have their own na
35. u may wish to have the sync input be unterminated Certain house sync configurations will require you to change the default position of the termination jumper on the main circuit board For example if you run your sync to several pieces of equipment using a tapped configuration using BNC T s as shown below only the last box box C would be terminated marked 75 ohm terminated on the circuit board Unfortunately some equipment does not allow the user to change the termination setting These pieces of equipment are usually provided with a per manent termination If you use the 386 with another piece of terminated equipment in tapped configuration you should unterminate marked unterminated on the circuit board the 386 s sync input The same is true if you wish to use several 386 s in a tapped configuration See Fig A 1 for the location of termination jumper Tapped Configuration 4 Fig A 1 Location of sync input termina tion jumper Terminated selection is shown cr LJ E C Li pa UNTERM 18 386 User Manual d b X PROFESSIONAL PRODUCTS 19 386 User Manual d b X PROFESSIONAL PRODUCTS pieia 0 A do Hauj syd Ped 6 MoT N8b 000000000000 UOIS EAUO AN 3dALXA
36. y com ponents of the signal are separated in Fig 3c to illustrate this more clearly As you can see the low frequency signal simply gets distorted but maintains most of its signal characteristics while sections of the high frequency signal are com pletely lost With dbx Type IV its mapping preserves high frequency signal information as illustrated in Fig 3d since the signal is confined within the Type 1 Over Region and never clips The dashed line indicates the original input signal level Below the Over Region no mapping occurs while above this mapping keeps all peaks of the signal below the A D clip level thus preserving the high frequency content of the signal 22 386 User Manual d b X PROFESSIONAL PRODUCTS Amplitude Time Figure 3a Signal Having Low and High Frequency Content Amplitude A D Clip Level Time A D Clip Level Figure 3b Signal of Fig 3a Going Beyond the A D Clip Level d b X PROFESSIONAL PRODUCTS 386 User Manual 23 Amplitude High Frequency Information Completely Lost High Frequency Content A D Clip Level Low Frequency Content Time A D Clip Level x 4 High Frequency Information Completely Lost Figure 3c Disproportionate Loss of High Frequency Information Due to Clipping Amplitude 0dB FS A D Clip Level TYPE IV Over Region 4 Time TYPE Over Region 0dB FS A D Clip Level Figure 3d Type IV Mapping Preserves High Frequency Information Now you re
Download Pdf Manuals
Related Search