286 ® Mic Preamp/Processor User Manual Professional Audio Equipment
IMPORTANT SAFETY INFORMATION 286 WARNING FOR YOUR PROTECTION READ THE FOLLOWING: KEEP THESE INSTRUCTIONS HEED ALL WARNINGS FOLLOW ALL INSTRUCTIONS 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.
286 IMPORTANT SAFETY INFORMATION ELECTROMAGNETIC COMPATIBILITY This unit conforms to the Product Specifications noted on the Declaration of Conformity. Operation is subject to the following two conditions: • t his device may not cause harmful interference, and • this device must accept any interference received, including interference that may cause undesired operation. Operation of this unit within significant electromagnetic fields should be avoided. • use only shielded interconnecting cables. U.K.
Table of Contents Section 1 - Introduction.........................................1 1.1 Service Contact Info.......................................2 1.2 Warranty.......................................................3 Section 2- Operating Controls.................................4 2.1 Rear Panel....................................................4 2.2 Front Panel...................................................5 Section 3 - Basic Operation....................................10 3.
286 286s Introduction Section 1 Section 1 - Introduction Congratulations on choosing the dbx 286s Mic Preamp/Processor. The 286s is a powerful, user-friendly unit, providing concise and intuitive controls for all your mic processing needs, whether you use a microphone to record vocals and acoustic instruments, sample acoustic sounds, or for a public address system installation.
Section 1 Introduction 286s 286 1.1 Service Contact Info 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 bottom 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 manual.
286 286s Introduction Section 1 1.2 Warranty 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 burden 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.
Section 2 286s 286 Operating Controls Section 2 - Operating Controls 2.1 Rear Panel s s s s s MIC INPUT Jack The 286s MIC INPUT jack supports professional and home studio microphones by accepting either balanced or unbalanced signal through an XLR connector. Pins 2 and 3 are symmetrically balanced and floating; thus, either can be used as “HOT” without difficulty. Pin 2 is in phase with the TIP of all 1/4” connectors. Pin 1 is connected to the 286s chassis ground.
286 286s Operating Controls Section 2 To use the INSERT jack to MULT the preamp out (i.e., to provide an output with a buffered version of the signal after the Mic Preamp circuitry, but before the Processing Section), insert a Mono 1/4” plug fully into the INSERT jack, then pull the plug out one click. Plug the other end of the cable to the appropriate load. This will still allow the original signal path to continue to the Processing Section without interruption.
Section 2 Operating Controls 286s 286 of the mic signal and additional gain exceeds the circuit’s capabilities; reduce gain via the MIC GAIN control. Set the MIC GAIN control so that the CLIP LED never lights. The LEVEL LEDs can also be used to check the strength of the input signal. For example, the 286s does not support low level microphones plugged into its 1/4” INPUT jack; in this case, the LEVEL LEDs would not light, because the signal is too low.
286 286s Operating Controls Section 2 Compressor DRIVE Control The DRIVE control determines the overall amount of gain reduction by setting the signal level going into the gain control circuitry. Turning DRIVE clockwise will increase the input signal, and therefore increase the amount of applied gain reduction. Turning DRIVE fully counterclockwise (to OFF) allows the compressor to pass all signals unattenuated, effectively bypassing the compressor.
Section 2 Operating Controls 286s 286 Enhancer Note: The low and high frequency enhancers are off when their respective DETAIL controls are set to OFF. LF DETAIL Control The 286s Low Frequency enhancement simultaneously applies an 80Hz boost and 250Hz cut to the program. This lets you apply substantial bass boost without making the program sound muddy or boomy due to excessive mid-bass boost.
286 286s Operating Controls Section 2 Readjust as needed to gate out noise -- external, as well as hiss from the unit. The 286s other processing can add substantial gain to a signal, especially at higher settings, thereby increasing the noise floor. Output GAIN (dB) Control and CLIP LED The OUTPUT GAIN control sets the level at the line output. The OUTPUT GAIN control is especially useful to compensate for the RMS level changes which result from the 286s processing effects.
Section 3 Basic Operation 286s 286 Section 3 - Basic Operation 3.1 Connecting the 286s to Your System The 286s can be used with any low-level microphone signal (via the MIC INPUT) or any line-level device (via the LINE INPUT). Some common line-level devices include: mixing consoles, electronic musical instruments, patch bays, and signal processors. For all connections, refer to the following steps: 1. Turn Off all equipment before making any connections. 2. Mount the 286s in a rack.
286 286s Basic Operation Section 3 Press the HIGHPASS button In to cut signals below 80Hz by 18dB/octave, effectively filtering out mic proximity effects, hum, rumble, wind and other low frequency “undesirables.” Use the MIC GAIN control to achieve the best definition and character possible from your microphone. The 286s Mic Preamp delivers up to 60dB of sonically transparent gain to reveal the detail and audio signature of even the most esoteric mics.
Section 3 Basic Operation 286s 286 by blowing air through a constricted (narrow) mouth opening or across the edge of the teeth, as in the “s” and “sh” in “sash.” Sibilants contain predominantly high frequency components with a sharp rise above 1kHz and most of the energy in the 4kHz to 10kHz band, centered on 6kHz to 8kHz. Adjust the De-Esser’s frequency control to set the frequency above which the 286s responds to audio containing sibilants.
286 286s Basic Operation Section 3 to pass. If the input signal is below the threshold, the gate “closes” and the input signal is attenuated. With sufficient attenuation, it effectively cuts that signal off. On the 286s, the amount of attenuation is set with the EXPANSION RATIO control. The 286s gate provides more flexibility than traditional switch gates because it actually functions as a combination gate/expander. Where switch gates are generally only suitable for a limited number of uses (e.g.
Section 3 286s 286 Basic Operation slow the compressor’s release time, set the DENSITY control to 0. Set the De-Esser frequency control to 4kHz (12:00 position). Adjust the De-Esser THRESHOLD control to reduce the vocalist’s sibilance. Use the HF DETAIL, to taste, to add life to the vocal. Defeat the LF DETAIL by setting it to OFF. Set the Expander/Gate THRESHOLD and EXPANSION RATIO controls starting with a setting of around 11:00.
286 286s Section 3 Basic Operation Enhancer Note: The High and Low Frequency Enhancers are OFF when their respective DETAIL controls are set to the “off” position. Suggested Usage: Female Voice Male Voice Keyboard Guitar Bass Guitar Drums Strings/ Horns Club Sound/DJ LF Detail -- HG Detail ¤ ◊ ¤ ◊ ◊ ◊ ¤ ¤ ◊ ◊ ◊ ◊ ¤ ¤ ¤ ¤ Recommended; These sound sources can be effectively re-energized and enhanced with treatment. Use to taste.
Section 4 Problems, Possible Causes, Solutions 286s 286 Section 4 - Problems, Possible Causes, Solutions Always verify that the problem is not in the source material being fed into the 286s, or in the other parts of the system. If you still have problems when using the 286s, consider the following remedies. Noise Rushups, Hiss Buildup Higher DRIVE settings on the compressor often add gain to the signal. If the signal already has substantial hiss, the compression can actually increase the hiss.
286 286s Problems, Possible Causes, Solutions Section 4 that the red (-) THRESHOLD LED (located to the right of the EXPANSION RATIO control) does not light until the required signal is finished. Lispy Vocals With higher settings of the De-Esser THRESHOLD or Expander/Gate THRESHOLD controls, a vocal performance can be marred by resultant lisps (i.e., where s and z sounds are heard as th sounds). Lisps can usually be corrected by reducing the De-Esser THRESHOLD, or the Expander/Gate THRESHOLD, or both.
Section 5 Technical Support and Factory Service 286s 286 Section 5 - Technical Support and Factory Service The 286s is an all-solid-state product with components chosen for high performance and excellent reliability. Each 286s is tested and calibrated at the factory and should require no internal adjustment of any type throughout the life of the unit. We recommend that your 286s be returned to the factory only after referring to the manual and consulting with Customer Service.
286 286s Technical Specifications Section 6 MIC INPUT Impedance Maximum Level Gain Adjustment Range Phantom Power CMRR EIN Floating balanced, Pin 2 Hot ~ 4.2kΩ Balanced 0.25Vrms, Gain=30dB +0dB ... +60dB +48VDC, applied to XLR pins 2 and 3 through 6.
Section 6 Technical Specifications 286s 286 ENHANCER HF Detail Characteristic Program-controlled shelving equalizer, approximately 15dB maximum HF boost LF detail Characteristic Bell-shaped boost @ 80Hz, bell-shaped cut @250Hz, ratio is approximately 2:1 EXPANDER/GATE Threshold Range Expansion Ratio Maximum Depth Attack Time Release Time OFF ... +15dBu Adjustable 1.5:1 ...
286 286s Section 7 - Block Diagram 21
286s 286 22
286 286s 23
6 8760 South Sandy Parkway • Sandy, Utah 84070 Phone: (801) 568-7660 • Fax (801) 568-7662 Int’l Fax: (801) 568-7583 Visit us online at www.dbxpro.
