dbx Pro 376 manuale d’uso

® 376 V acuum T ube Channel Strip w/Digital Out User Manual[...]

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 APPAR[...]

U.K. MAINS PLUG WARNING A 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[...]

T able of Contents 376 Intr oduction 0.1 Defining the 376................................................i 0.2 Service Contact Info .........................................ii 0.3 W arranty ............................................................ii 0.4 Installation Recommendations ........................iii Section 1 - Getting Star ted 1.1 Rea[...]

INTRO CUSTOMER SER VICE INFO 376 DEFINED W ARRANTY INFO ® INTRODUCTION 376[...]

Intr oduction ® 376 User Manual i 376 Congratulations on your purchase of the dbx 376 V acuum Tube Channel Strip with digital capa- bilities. For over 25 years, dbx has been the industry leader in dynamics processing. With the introduction of the 376, the standard for channel strip processors has now been completely redefined. Conventional channel[...]

® Intr oduction 376 376 User Manual If you require technical support, contact dbx Customer Service. Be prepared to accurately describe the problem. Know the serial number of 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 d[...]

Intr oduction ® 376 User Manual iii 376 FOR RACK MOUNT USE ONL Y - Install the 376 in your rack with the provided rack screws. When installed in a rack, the unit should be positioned with enough room (at least one 1U above the and 1U below the unit) to allow proper ventilation. The 376 should not be mount- ed above or below anything that generates[...]

Getting Started ® Getting Started Section 1 376[...]

Getting Star ted ® 376 User Manual 2 Section 1 376 P o wer Switch Turns the 376 on and off. IEC P o wer Cor d Receptacle This is the power cord receptacle of the 376. An IEC cord is included with the shipped prod- uct. AES/EBU Digital Connector T he 376 pr o vi d es AES / EB U di gi t al o ut pu t f or m at t i n g t h r ough t h e XLR c o nn ec t[...]

® 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 Th[...]

Getting Star ted ® 376 User Manual 4 Section 1 376 Lo w control This control varies the gain of the low frequency equalization; the gain range is -15 to +15 dB. This filter is a low shelving filter at 80 Hz. Mid contr ol This control varies the gain of the mid frequency equalization; the gain range is -15 to + 15 dB. The mid frequency filter is a [...]

® Output Le vel This knob controls the overall level of the output signal, and ranges from -20 to +20dB. 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[...]

Getting Star ted ® 6 Section 1 376[...]

ANALOG APPLICA TIONS ® ANALOG APPLICA TIONS Section 2 376[...]

Analog Applications ® 3 376 User Manual 8 Section 2 376 • Turn off all equipment before making any connections. • Install the 376 in your rack with the provided rack screws. It is essential that when the 376 is being mounted in a rack mounting enclosure, the unit should be positioned with enough room (at least 1U of space above the unit and 1U[...]

® 3). Turn the 376’s DRIVE control to the minimum position. Turn the OUTPUT LEVEL control to the 12 o’clock position, and apply power to the 376. Make sure your console’s gain fader is at the nominal level and begin to slowly increase the gain of the 376 using the DRIVE control. Y ou should increase the gain until the mixing/recording device[...]

Analog Applications ® 376 User Manual 10 Section 2 376 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 376 is connected. As you increase the setting of the DRIVE control, you should begin to hear the input of the 376 running thro[...]

DIGIT AL APPLICA TIONS ® DIGIT AL APPLICA TIONS Section 3 376[...]

Dither Switch This switch is used to select the dither type algorithms including: TPDF , SNR 2 , or None. Dither is random noise that is added to the audio signal which effectively eliminates the harmonic dis- tortion created by truncation. See the“T runcation” graph in section D.2 of the Appendix. The LED will be lit RED for the SNR 2 or GREEN[...]

AES/EBU Digital Connector T he 376 pr o vi d es AES / EB U di gi t al o ut pu t f or m at t i ng t hr o ugh t he X LR connect or . B e s ur e t o use s ho r t l engt hs of 110 Ω d ig ita l ca b le s ra th e r th a n s ta n d a rd X L R to X L R ca b le s. U s in g th e c o rr e c t c abl es w i l l pr ev ent di gi t al dr opout s a nd ot he r i n[...]

Rear P anel Connections • Connect the source to the desired 1/4” TRS or XLR input. • Connect the AES/EBU or S/PDIF output of the 376 and run into the AES/EBU or S/PDIF input interface of the DA W (CPU). Fr ont P anel Digital Output F eatures 1). Use the METER switch to select digital output metering. 2). Use the DITHER switch to select the de[...]

Rear P anel Connections • Connect the source to the desired 1/4” TRS or XLR input jack. • Connect the AES/EBU or S/PDIF output of the 376 and run into the AES/EBU or S/PDIF input of the digital mixer . Fr ont P anel Digital Output F eatures 1). Use the METER switch to select digital output metering. 2). Use the DITHER switch to select the des[...]

Rear P anel Connections • Connect the source to the desired 1/4” TRS or XLR input. • Connect the AES/EBU or S/PDIF output of the 376 and run into the AES/EBU or S/PDIF input interface of the DA W (CPU). Fr ont P anel Digital Output F eatures 1). Use the METER switch to select digital output metering. 2). Use the DITHER switch to select the de[...]

Rear P anel Connections • Connect the source to the desired 1/4” TRS or XLR input jack. • Connect the AES/EBU or S/PDIF output of the 376 and run into the AES/EBU or S/PDIF input of the digital mixer . Fr ont P anel Digital Output F eatures 1). Use the METER switch to select digital output metering. 2). Use the DITHER switch to select the des[...]

The 376 gives you the unique option of utilizing the 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 [...]

APPENDIX Sync Input Info Block Diagram dbx T ype IV™ White Paper Noise-Shaping Algorithms T runcation Specifications ® APPENDIX Appendix 376[...]

Appendix A A- Sync Input Info INSTRUCTIONS FOR QUALIFIED SERVICE PERSONNEL: CAUTION : These servicing instructions ar e for use by qualified service personnel only. T o r educe the risk of electric shock, do not per form any servicing other than that contained in the operating instructions unless you are qualified to do so. Refer all servicing to q[...]

Microphone Input +48V Over easy“ Slow 20dB Pad Phase In vert Low Cut dbx TYPE IV Conversion System DSP Dither Sample Rate Wo r d Length Output Format Shape Peak LEDs EQ Clip LED Threshold LED De-Esser Gain Reduction LED Line/Mic 12AU7 T ube Drive Output Level Analog Outputs Rear Panel Line Input Front Panel Instrument Input Bar graph Meter Analog[...]

Appendix C dbx T ype IV™ Con v ersion System White P aper b y Ro ger 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. [...]

to-noise perfor mance 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 moni[...]

Appendix C 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 inf[...]

Figure 3b - Signal of Fig. 3a Going Beyond the A/D Clip Lev el Amplitude Time A/D Clip Lev el A/D Clip Lev el Figure 3a - Signal Having Low and High F requency Content Amplitude Time Appendix C ® Appendix 25 376 User Manual 376[...]

Appendix C Now you’re probably wondering, “What’s the catch? I can’t get something for nothing so what did I give up?” Y ou 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 tec[...]

16-Bit 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, A verages= 32; Graph Steps= 1024. (a) 24-Bit word, (b) 16-Bit truncated output, no dither . Parameters: Input -60dBFS, 1 kHz; FFT Length= 2048, Sample Rate= 48 Khz, A vera[...]

Appendix D Microphone Input Connec t or: Fe m al e XLR Pi n 2 H ot T y p e : E le c t ro n ica lly b a la n c e d /u n b a la n c e d I m ped anc e: 330 Ω M axi m um I nput Le vel : - 9 dBu or + 11 dBu w i t h 20 dB pa d enga ged CM R R: > 40dB , Typi ca l l y 55dB Equi val en t I np ut N o i s e: Typi ca l l y - 120 dBu w i t h a 150 Ω sour[...]

® 8760 South Sandy Pkwy . Sandy , Utah 84070 Phone: (801) 568-7660 F ax: (801) 568-7662 Int’l F ax: (603) 672-4246 Questions or comments? E•mail us at: customer@dbxpro .com or visit our W orld Wide W eb home pag e at: www .dbxpr o.com A Harman International Company 18-0099[...]