ACP88 Eight Channel Compressor/Limiter/Gate User' Manual s Version 1.2 ACP88 EIGHT CHANNEL COMPRESSOR/LIMITER/GATE USERSMANUAL Version1.2 Copyright 1998,2000,2001 PreSonus Audio Electronics, Incorporated. All rights reserved. WARRANTY PreSonus Limited Warranty PreSonus Audio Electronics Inc. warrants this product to be free of defects in material and workmanship for a period of one year from the date of original retail purchase. This warranty is enforceable only by the original retail purchaser. To be protected by this warranty, the purchaser must complete and return the enclosed warranty card within 14 days of purchase. During the warranty period PreSonus shall, at its sole and absolute option, either repair or replace, free of charge, any product that proves to be defective on inspection by PreSonus or its authorized service representative. To obtain warranty service, the purchaser must first call or write PreSonus at the address and telephone number printed below to obtain a Return Authorization Number and instructions of where to return the unit for service. All inquiries must be accompanied by a description of the problem. All authorized returns must be sent to the PreSonus repair facility postage prepaid, insured and properly packaged. PreSonus reserves the right to update any unit returned for repair. PreSonus reserves the right to change or improve the design of the product at any time without prior notice. This warranty does not cover claims for damage due to abuse, neglect, alteration or attempted repair by unauthorized personnel, and is limited to failures arising during normal use that are due to defects in material or workmanship in the product. Any implied warranties, including implied warranties of merchantability and fitness for a particular purpose, are limited in duration to the length of this limited warranty. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you. In no event will PreSonus be liable for incidental, consequential or other damages resulting from the breach of any express or implied warranty, including, among other things, damage to property, damage based on inconvenience or on loss of use of the product, and, to the extent permitted by law, damages for personal injury. Some states do not allow the exclusion of limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific legal rights, and you may also have other rights, which vary form state to state. This warranty only applies to products sold and used in the United States of America. For warranty information in all other countries please refer to your local distributor. Limited Warranty Outside of The U.S. PreSonus Audio Electronics products are warranted only in the country where purchased, through the authorized PreSonus distributor in that country, against defects in material and workmanship. The specific period of this limited warranty shall be that which is described to the original retail purchaser by the authorized PreSonus dealer or distributor at the time of purchase. PreSonus does not, however, warrant its products against any and all defects: 1) arising Out of materials or workmanship not provided or furnished by PreSonus, or 2) resulting from abnormal use of the product or use in violation of instructions, or 3) in products repaired or serviced by other than authorized PreSonus repair facilities, or 4) in products with removed or defaced serial numbers, or 5) in components or parts or products expressly warranted by another manufacturer. PreSonus agrees, through the applicable authorized distributor, to repair or replace defects covered by this limited warranty with parts or products of original or improved design, at its option in each respect, if the defective product is shipped prior to the end of the warranty period to the designated authorized PreSonus warranty repair facility in the country where purchased, or to the PreSonus factory in the U.S., in the original packaging or a replacement supplied by PreSonus, with all transportation cost and full insurance paid each way by the purchaser or owner. All remedies and the measure of damages are limited to the above services. It is possible that economic loss or injury to person or property may result from the failure of the product; However, even if PreSonus has been advised of this possibility, this limited warranty does not cover any such consequential or incidental damages. Some states or countries do not allow the limitations or exclusion of incidental or consequential damages, so the above limitation may not apply to you. Any and all warranties, express or implied, arising by law, course of dealing, course of performance, usage of trade, or otherwise, including but not limited to implied warranties of merchantability and fitness for a particular purpose, are limited to a period of two years from either the date of original retail purchase or, in the event no proof of purchase date is available, the date of manufacture. Some states or countries do not allow limitations on how long an implied warranty last, so the above limitations may not apply to you. This limited warranty gives you specific legal rights, and you may also have other rights which vary from state to state, country to country. PreSonus Audio Electronics, Inc. 7257 Florida Blvd. Baton Rouge, LA 70806 (225) 216-7887 Copyright 1998, 2000, 2001 PreSonus Audio Electronics, Incorporated. All rights reserved. TABLE OF CONTENTS 1 Overview 1.1 Introduction 1.2 Features 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 3 Controls&Connections Front Panel Basic Layout Compressor Controls Gate Controls Gain Bypass & Link Patch Panel Power BasicSetupandApplications 3.1 Some Basic Patching 3.2 Basic Applications 4 Technical 4.1 Specifications 4.2 Block Diagram OVERVIEW 1.1 INTRODUCTION Thank you for purchasing the PreSonus ACP-88 multi-channel dynamics processor. Your processor was designed using state of the art components to deliver crystal clear compression and noise gating for an infinite period of time. We believe the ACP-88 to be an exceptional sounding unit and an exceptional value. Feel free to contact us at 1-800-750-0323 anytime for any reason. We value your suggestions and your comments. PreSonus Audio Electronics is committed to constant product improvement and feel the best way to accomplish this task is by listening to the experts on our gear, our valued customers. We appreciate the support you have shown us through the purchase of our products. Please pay close attention to how you connect your ACP-88 to your system. Improper grounding is the most common cause of noise problems found in studio or live sound systems. We urge you to scan this manual before hooking up your ACP-88 to become familiar with its features and various applications. Good luck and enjoy your ACP-88! 1 . 2 FEATURES The following is a summary of your ACP-88' features: s ? Eight Compressors/Limiters. Each channel of your ACP-88 contains an audio Compressor that can also be setup as a Limiter by varying the ratio of compression. You have broad control over Threshold, Ratio, Attack and Release for each processor. You can select between Auto or Manual Attack and Release curves and Hard or Soft Knee compression types (refer to the application section of this manual for a quick tutorial on compression/limiting). The Compressor will prove to be very useful in many situations such as recording instruments or vocals that vary in loudness, or setting it up as a limiting device before your digital recorder to prevent distorting your digital recorder' s inputs. Live sound system processing is another great application where your ACP-88 can really take control. Eight Dynamic Noise Gates. Each channel of your ACP-88 has a separate dynamic noise gate that can be used to Gate an entire ? 5 OVERVIEW drum kit, clean up a noisy tape machine, isolate an instrument or separate a vocal from background noise. Each noise Gate provides control over Attack, Threshold, Release and Gate close Range. The Gate close range can be useful in creating a more natural sounding blend or mix when gating many instruments at once. ? Comprehensive Channel Linking. Using the Link function allows you to combine any combination of ACP-88 channels effectively forming a subgroup. When linked, all processors follow the setting of the Master processor which is always the processor furthest to the Left in a Link group. For example, you could Link together channels 7 and 8 to form a Stereo pair, channels 3, 4 and 5 to form a subgroup of processors, while channels 1, 2 and 6 remain available for independent applications such as compression, limiting, or gating as the situation dictates. Separate Bypass and Gain for Every Channel. Each Channel has a separate Bypass for auditioning a signal ` before and after' processing with the compressor, limiter, or the Gate and a Gain control to make up any loss in signal level resulting from the amount of compression being applied. Compressor Sidechain Jack on Every Channel. Each channel of your ACP-88 was designed with a special jack for spectral processing, compression keying and ducking applications. Sidechaining is useful for removing annoying sibilance from vocal tracks (de-essing) or automatically ducking tracks behind a narrator for ` auto mixing" a service, broadcast or performance. When multiple channels are Linked together, the Send of the Sidechain jack of the Master channel contains a mix of all the channels in the Link: a very cool feature allowing control over multiple channels of processing with one Sidechain send/return. (See the section on Sidechaining for application notes.) ? ? 6 OVERVIEW ? Separate Gate Sidechain/keying Jacks for Each Channel. Your ACP-88 also includes a separate jack on each channel for Gate sidechain/Keying. This is useful for synching an external sound to a snare track, for example, or putting equalizers or filters before the Gate key to enable Gating only the lower frequency of a kick drum, etc. Balanced/Unbalanced Inputs and Outputs. Your Acp-88 accepts either balanced or unbalanced inputs and outputs using tip-ring-sleeve (TRS) connectors. + 4dBu or ­ 10dBV. The internal operating level of your ACP-88 can be switched between +4dBu (pro levels) to ­10dBV (line levels), making it possible to use in virtually any application. ? ? 7 OVERVIEW To Get Help... Call Us: 1-800-750-0323, 9 AM to 5 PM, CST Visit our World Wide Web Site: http://www.presonus.com Email Us: presonus@presonus.com 8 CONTROLS & CONNECTIO NS 2.1 Front Panel Basic Layout Notice that the front panel is divided into eight identical sections. These are the eight signal processing chains of the ACP-88. Each channel contains: ? ? ? ? Compressor/Limiter Noise Gate Gain Makeup Link & Bypass Control 9 CONTROLS & CONNECTIO NS 2.2 Compressor Controls Threshold The Compressor Threshold sets the level at which compression begins. The below and above LED' over the Threshold knob indicate s whether the input signal is below or above the Threshold setting. When the signal is above the Threshold setting, it becomes ` eligible'for compression. Basically, as you turn the Threshold knob counter-clockwise, the input signal is compressed. (If you have a ratio setting of greater than 1:1.) Ratio Ratio sets the compression slope. This is defined as the output level versus the input level. For example, if you have the Ratio set to 2:1, any signal level above the Threshold setting will be compressed at a compression ratio of 2:1. This simple means that that for every 1dB of level increase into the compressor, the output will only increase ½ dB, thus producing a compression Gain reduction of 0.5 db. As you increase the Ratio, the compressor gradually becomes a limiter. A limiter is defined as a processor that limits the level of signal to the setting of the Threshold. For example, if you have the 10 CONTROLS & CONNECTIO NS Threshold knob set at 0 dB, and the Ratio turned fully clockwise, the Compressor becomes a Limiter at 0 dB. This means the signal will be limited to an output of 0 dB regardless of the input signal. Attack Attack sets the speed at which the compressor ` acts'on the input signal. A slow attack time (fully clockwise) allows the beginning envelope of a signal (commonly referred to as the initial transient) to pass through the compressor uncompressed, whereas a fast attack time (fully counterclockwise) immediately subjects the signal to the Ratio and Threshold settings of the compressor. The Attack control is only active when the Auto button is not pushed in. When the Auto button is pushed in, the compressor automatically determines the appropriate Attack time for compression. Release Release sets the length of time the compressor takes to return the Gain reduction back to zero (no gain reduction). Very short Rele ...