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ACP88 Eight Channel Compressor/Limiter/Gate User’ s Manual Version 1.2...
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ACP88 E I G H T C H A N N E L C O M P R E S S O R / L I M I T E R / G A T E USERS MANUAL Version 1.2 Copyright 1998,2000,2001 PreSonus Audio Electronics, Incorporated.
W A R R A N T Y 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.
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.
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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.
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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.
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OVERVIEW To Get Help… Call Us: 1-800-750-0323, 9 AM to 5 PM, CST Visit our World Wide Web Site: Email Us: presonus@presonus.com http://www.presonus.com...
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...
CONTROLS & CONNECTIO NS 2.2 Compressor Controls Threshold The Compressor Threshold sets the level at which compression begins. The below and above LED’ s over the Threshold knob indicate whether the input signal is below or above the Threshold setting. When the signal is above the Threshold setting, it becomes ‘...
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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 ‘...
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CONTROLS & CONNECTIO NS Soft The Soft button selects Soft Knee and Hard Knee compression curves. When this button is pushed in, Soft knee compression curves are used, otherwise hard knee compression curves are used. With Hard knee compression, the gain reduction applied to the signal occurs as soon as the signal exceeds the level set by the threshold.
CONTROLS & CONNECTIO NS 2.3 Gate Controls Attack The Gate attack control sets the speed at which the gate opens to allow signal to pass through it. This control is variable from 10 microseconds to 100 milliseconds. It is advisable to use slower Attack times when gating vocals or quieter instruments to avoid what is often described as gate ‘...
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CONTROLS & CONNECTIO NS signals below the Threshold setting are reduced in level by the amount set by the Range switch. The ‘ CLOSE’ LED above the Threshold knob indicates when the gate is closed (the signal level is below the threshold). If the Threshold is set fully counter-clockwise, the Gate is turned off (always open), allowing all signals to pass through unaffected.
CONTROLS & CONNECTIO NS 2.4 Gain Gain When compressing a signal, Gain reduction usually results in an overall reduction of level. The Gain control allows you to restore the loss in level which occurs due to the amount of compression used. (like readjusting the volume.) 2.5 Bypass &...
CONTROLS & CONNECTIO NS (presence or lack of signal), all metering should be referred to the Master channel’ s meter for the Gain reduction level of the Linked channels! 2.6 Patch Panel (Back) Input The Input jack accepts balanced tip-ring-sleeve or unbalanced tip- sleeve connectors.
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CONTROLS & CONNECTIO NS Output The output jack accepts balanced tip-ring-sleeve or unbalanced tip- sleeve connectors. The output will deliver up to +24 dBu in signal level, balanced or unbalanced. +4/-10 Switch This switch adjusts the internal operating level of your ACP-88 when it is connected to line level (0 dB = -10 dBV) gear.
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CONTROLS & CONNECTIO NS connector. This signal can then be processed by an equalizer for example to reduce sibilance 9de-essing) in a vocal track. The signal is then returned to the unit via the tip of the connector. The signal sent via the ring could be that of a narrator or vocalist.
CONTROLS & CONNECTIO NS 2.7 Power Power Connection The power jack on your ACP-88 accepts a standard IEC cord like those found on most computers and professional recorders. Your ACP-88 contains a custom built; internal power supply, no wall wart. This way you can be assured of clean power and rugged construction that will last! Power Selection Before powering up your ACP-88 for the first time, be sure to check...
BASIC SETUP & APPLIC ATIONS 3.2 Basic Applications Example setup compressing a voice or vocal track. Probably the most common use of a compressor is to control the dynamic range of a vocalist during a live performance or when recording. It is almost always necessary to compress a vocal take during a recording session.
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BASIC SETUP & APPLIC ATIONS out, Gate Threshold knob is fully counter-clockwise, Compressor Ratio knob is set to 1:1 (fully counter clockwise). To set the compressor: turn the Ratio to the 2:1 mark on the legend. With the vocalist yodeling into the mic, turn the compressor’ s Threshold until the gain reduction meters read about –7dB.
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BASIC SETUP & APPLIC ATIONS Attack knob clockwise. You should notice that the beginning 'transient' of your snare sound is starting to jump out of the speakers and slap you in the face. This becomes even more noticeable when using digital reverberation on the snare.
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BASIC SETUP & APPLIC ATIONS Compressing bass guitar. Very similar to compressing vocals, the bass guitar is almost always compressed or limited during recording. Start with the setting described above for vocals. Vary the Compression Ratio, Attack and Release to suite your taste. Compressing acoustic guitar.
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BASIC SETUP & APPLIC ATIONS such as 2kHz to 8kHz, the Compressor will apply the Gain reduction more to the sibilance because it is now 'seeing' more signal around the frequency of the sibilance. You will need to adjust the frequency of the equalizer to locate your source of sibilance more precisely.
TECHNICAL 4.1 Specifications Number of Channels...8 Dynamic Range...>115dB Signal to Noise Ratio...>95dB Headroom ...+24dBu, Unbalanced; +18dBu Balanced Frequency Response ...10Hz to 50kHz Crosstalk ...>82db @ 10kHz Compression Threshold Range ...-40dBu to +20dBu Compression Ratio ...1:1 to 20:1 Compressor Attack Time...0.02ms to 200ms Compressor Release Time ...0.5sec to 500sec Auto Attack and Release ...Program Dependent Gate Attack Time ...0.01ms to lOOms...
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