User's Manual BK 2.0 COMPRESSOR /LIMITER /GATE R LTO www.altoproaudio.com Version 2.0 Dec.
SAFETY RELATED SYMBOLS Never cut off the internal or external protective grounding wire or disconnect the wiring of protective grounding terminal. CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN Operating Conditions This apparatus shall not be exposed to dripping or splashing and that no objects filled with liquids, such as vases, shall be placed on this apparatus. To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture. Do not use this apparatus near water.
PREFACE Dear Customer: Thanks for choosing LTO BK 2.0 Compressor/Limter/Gate and thanks for choosing one of the results of TEAM job and researches. For our LTO AUDIO LTO AUDIO TEAM, music and sound are more then 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.
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. CONTROLS..............................................................................................................
1. INTRODUCTION You are now the owner of an LTO BK 2.0 Compressor/Limiter/Gate. The BK 2.0 is a very powerful dynamic processor. We have included in it several innovative circuit designs that make the BK 2.0 a very versatile processor: smart and fast recognition of the program, adjustable Expander/Gate and very low distortion Voltage Control Amplifier (VCA).
2.1.2 Introducing Audio Dynamics The human ear can detect the noise generating 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 if dynamic capacity of various devices when compare to the human ear. More problems occur when handling high level signals and low level signals.
2.1.4 More about noise: Expanders and Noise-Gates A lot of instruments such as microphones, amplifiers, guitar pickups, etc generate some noise, either at low frequencies (hum) or at high frequencies (hiss) Such noise will inevitably interfere with the quality of your audio signal. Now, if you scream into a microphone you will not hear the noise generated by such microphone because such noise will be "masked" by the higher level of the signal, your voice in this case.
2.Close LED This LED illuminates when expansion occurs.
11. PROCESS control This control renews any high frequencies lost through the compression process for natural sounding dynamics control, which can be varied from off to 6. Please note that the enhancer control is only used when compression is taking place. 3.
4. READY TO ROLL? 4.1 Expander/Gate Section Chart.3: Function of an expander As we told you previously in this Manual the downward expander will reduce automatically the level of the audio signal when such signal is below a set threshold. So the expander is the opposite of the compressor/limiter. We also explained to you how the ratio curve of the expander is flat while a noise gate it is more brutal processor: It simply cut-off the entire signal below a certain set threshold. The BK 2.
4.2.2 Ratio control This control sets the change of input level to output level but only for the signals that exceed the threshold. The scale of the ratio control on the front panel (calibrated in dB) indicates how much input level is required to increase the output level by 1 dB. If you have a ratio equal to 1:1 you will get the same level of input and output signal: So, no level change.
4.2.8 Gain Reduction Meter This consists of 8 LED on the front of the BK 2.0. Through this Led meter you can visualise the amount of gain reduction at any given time. Chart.6: The effect of a compressor can be expressed as the amount of gain reduction that is taking place for any given input 4.3 Limiter Section How fast is the compressor to react to a signal which is above the threshold point? This is determined by the attack time.
a. Wiring Configuration Both types of connectors available on BK 2.0 can be wired in balanced and unbalanced modes. Please see following drawing for details: For 1/4" TRS jack 1/4"TRS jack Unbalanced input 1/4"TRS jack Balanced input For XLR connector XLR Unbalanced input XLR Balanced input b. In Line Connection Please see following drawing for details.
1/4" TRS insert Tip (S Tip Ring Sleeve 13
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7. BLOCK DIAGRAM Chart.8: Block diagram of the BK 2.
8. WARRANTY 1. WARRANTY REGISTRATION CARD To obtain Warranty Service, the buyer should first fill out and return the enclosed Warranty Registration Card within 10 days of the Purchase Date. All the information presented in this Warranty Registration Card gives the manufacturer a better understanding of the sales status, so as to purport a more effective and efficient after-sales warranty service.
SEKAKU ELECTRON IND. CO., LTD NO.1, LANE 17, SEC. 2, HAN SHI WEST ROAD, TAICHUNG, 401 TAIWAN http://www.altoproaudio.com Tel:886-4-22313737 email: alto@altoproaudio.com Fax:886-4-22346757 All rights reserved to ALTO. All features and content might be changed without prior notice. Any photocopy, translation, or reproduction of part of this manual without written permission is forbidden.
