ALTO ACL4 (EN)ALTO ACL4 (EN), INSTRUKCJE OBSŁUGI SPRZĘTU, PO ANGIELSKU (EN)
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User's Manual ACL4 QUAD COMPRESSOR/LIMITER LTO R www.altoproaudio.com Version 1.1 September 2005 English SAFETY RELATED SYMBOLS Fuse To prevent fire and damage to the product, use only CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN the recommended fuse type as indicated in this manual. Do not short-circuit the fuse holder. Before replacing the fuse, make sure that the product is OFF and disconnected from the AC outlet. This symbol, wherever used, alerts you to the pre- sence of un-insulated and dangerous voltages with- in the product enclosure. These are voltages that may be sufficient to constitute the risk of electric shock or death. Protective Ground Before turning the product ON, make sure that it is connected to Ground. This is to prevent the risk of electric shock. Never cut internal or external Ground wires. Likewise, never remove Ground wiring from the Protective Ground Terminal. This symbol, wherever used, alerts you to impo- rtant operating and maintenance instructions. Please read. Protective Ground Terminal Operating Conditions AC mains (Alternating Current) Always install in accordance with the manufacturer's instructions. To avoid the risk of electric shock and damage, do not subject this product to any liquid/rain or moisture. Do not use this product when in close proximity to water. Do not install this product near any direct heat source. Do not block areas of ventilation. Failure to do so could result in fire. Keep product away from naked flames. Hazardous Live Terminal ON: Denotes the product is turned on. OFF: Denotes the product is turned off. WARNING Describes precautions that should be observed to prevent the possibility of death or injury to the user. CAUTION Describes precautions that should be observed to prevent damage to the product. IMPORTANT SAFETY INSTRUCTIONS Disposing of this product should not be placed in municipal waste and should be Separate collection. Read these instructions Follow all instructions Keep these instructions. Do not discard. Heed all warnings. Only use attachments/accessories specified by the manufacturer. WARNING Power Supply Ensure that the mains source voltage (AC outlet) matches the voltage rating of the product. Failure to do so could result in damage to the product and possibly the user. Unplug the product before electrical storms occur and when unused for long periods of time to reduce the risk of electric shock or fire. Power Cord and Plug Do not tamper with the power cord or plug. These are designed for your safety. Do not remove Ground connections! If the plug does not fit your AC outlet seek advice from a qualified electrician. Protect the power cord and plug from any physical stress to avoid risk of electric shock. Do not place heavy objects on the power cord. This could cause electric shock or fire. External Connection Always use proper ready-made insulated mains cabling (power cord). Failure to do so could result in shock/death or fire. If in doubt, seek advice from a registered electrician. Cleaning Do Not Remove Any Covers Within the product are areas where high voltages may present. To reduce the risk of electric shock do not remove any covers unless the AC mains power cord is removed. Covers should be removed by qualified service personnel only. When required, either blow off dust from the product or use a dry cloth. Do not use any solvents such as Benzol or Alcohol. For safety, keep product clean and free from dust. Servicing Refer all servicing to qualified service personnel only. Do not perform any servicing other than those instruc- tions contained within the User's Manual. No user serviceable parts inside. 1 PREFACE Dear Customer: Thanks for choosing LTO ACL4 Compressor/Limter/Gate and thanks for choosing one of the results of LTO AUDIO TEAM job and researches. For our LTO AUDIO TEAM, music and sound are more than a job... are first of all passion and let us say... our obsession! We have been designing professional audio products for a long time in cooperation with some of the major brands in the world in the audio field. The LTO line presents unparalleled analogue and digital products made by Musicians for Musicians in our R&D Centers in Italy, Netherlands, United Kingdom and Taiwan. The core of our digital audio products is a sophisticated DSP (Digital ound rocessor) and a large range of state of the art algorithms which have been developed by our Because we are convinced you are the most important member of LTO AUDIO TEAM and the one confirming the quality of our job, we like to share our work and our dreams with you, paying attention to your suggestions and your comments. Following this idea we create our products and we will create the new ones! From our side, we guarantee you and we will guarantee you also in future the best quality, the best fruits of our continuous researches and the best prices. Our LTO ACL4 is the result of many hours of listening and tests involving common people, area experts, musicians and technicians. The results of this effort is that you can acquire an extremely efficient and universal dynamics processor. It contains several new circuits design which make the unit an ultimate dynamic processor: intelligent program recognition, Smart Expander/Gate and super low distortion VCA (Voltage Controlled Amplifier). Nothing else to add, but that we would like to thank all the people that made the LTO ACL4 a reality available to our customers, and thank our designers and all the LTO staff, people who make possible the realization of products containing our idea of music and sound and are ready to support you, our customers, in the best way, conscious that you are our best richness. Thank you very much. LTO AUDIO TEAM 2 SP Software Team for many years. TABLE OF CONTENTS 1. INTRODUCTION......................................................................................................................................4 2. THE CONCEPT BEHIND........................................................................................................................4 2.1 Some technical stuff 2.2 Voltage Controlled Amplifier (VCA) 2.3 Inputs 3. CONTROL ELEMENTS .........................................................................................................................6 4. READY TO ROLL? .................................................................................................................................7 4.1 Compressor Section 4.2 Peak Limiter Section 5. INSTALLATION AND CONNECTION.....................................................................................................9 ...... 5.1 Mains Connection 5.2 Audio Connection 5.3 Rack Mounting 6. TECHNICAL SPECIFICATIONS .................................................................................................................................11 7. WARRANTY .............................................................................................................................................................12 3 1. INTRODUCTION You are now the Owner of an LTO ACL4 Quad Compressor/Limiter. The ACL4 is a very powerful dynamic processor. We have included in it with several innovative circuit designs that make the ACL4 a very versatile processor: smart and fast recognition of the program and very low distortion Voltage Control Amplifier (VCA). Feature List: Smart Knee Control Compressor (SKC) Soft knee or hard knee? This is the question! SKC combines both: In the "soft knee" mode you can control the program material so that the compression will be the most musical and inaudible. On the other hand, the hard knee function is used for better precision, limiting signal peaks with precision and will allow you to add creativity to the dynamic processing. This function also allows you to protect other equipment in the signal loop against distortion. The AUTO Function Thanks to the AUTO function attack and release times of the program materials are automatically analysed in your ACL4 unit. Then the dynamic range of the program is heavily compressed in a very musical way so that there will not be any audible breathing or pumping effect. Smart Gain Control peak limiter (SGC) This function includes two important functions: Clipper and program limiter. The peak limiter will be activated above a certain threshold that is adjusted by the User and will radically restrict signal peaks. But what about if the threshold of the Limiter is surpassed only for a few milliseconds? SGC will turn on automatically and reduce the output signal so that you will not hear any distortion. Smart, isn't it? The SGC proves to be very efficient in loudspeaker protection and to reduce undesired peaks in digital situations. 2. THE CONCEPT BEHIND 2.1 Some technical stuff Good old analog technology: It will allow us to manufacture audio equipment with a very high dynamic range: up to 125 dB. But the dynamic range of digital equipment is more or less 25 dB. A further reduction in dynamic range occurs with the use of tape recorders and/or vinyl records. 2.1.1 It is not just Music Yes, a piece of electronic will produce some noise. When the current flows through a conductor this will generate a certain movement of the electrons and therefore: noise. And throughout the whole spectrum of audio. Imagine what happens when this inherent noise will be amplified. Yes, today one can use "low-noise"components but still such components will present a certain level of residual noise. For example with tape recorders it will not be possible to get an S/N (signal to noise) ratio better than 70dB. This level would not be accepted today by the increased sensitivity of the listeners. It is possible to improve the performance of a tape recorder: Absolutely no! 2.1.2 Introducing Audio Dynamics The human ear can detect the noise generated by falling leaves as well as the roar generated by the taking off space shuttle. Unfortunately no analog, nor digital device can reproduce such wide spectrum. Please look at Chart. 1 and you will see the difference when dynamic capacity of various devices compare to the human ear. More problems occur when handling high level signals and low level signals. When you reach the high level limit you may incur in distortion because of the dynamic range of the instrument therefore a certain "reserve" must be maintained to avoid distortion. This reserve is known as "headroom" and it is usually set at 10-20 dB. Would not be easier just to reduce the operating level? Yes it would but you would put low level music signals at the same level of the basic noise floor so the overall quality of the signal would be highly deteriorated. Please look at Chart. 2 and note the Usable dynamic range (including headroom) versus high level distortion generated by peaks, and Noise floor level. 4 [ Pobierz całość w formacie PDF ] |
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