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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).

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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 control the program 
material so that the compression will be the most musical and inaudible. ON the other end, 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

Your BK 2.0 includes and AUTO function switch on the front panel. Thanks to the AUTO function attack and release times of 
the program materials are automatically analysed. 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 Ratio Control expander (SRC)

Durinmusic pauses or when a quiet session occurs, the noise floor maybe highly amplified and this effect 
may be exaggerated because of inappropriate use of the compression ratio. The SRC control will adjust the 
expansion depending on the input signal so that those signals, which are slightly above the noise floor level, 
will get the major benefits.

Smart Gate 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.

Ok,Ok, you do not want to get advantage of our AUTO function and be the Master of your own mix.
We have provided your BK2.0 with User Adjustable attack and release time for the best total manual control.

Attack and Release Controls:

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 less. A further reduction in dynamic 
range occurs with the use of tape recorders and/or vinyl records.

2. THE CONCEPT BEHIND

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!

Summary of Contents for BK 2.0

Page 1: ...BK 2 0 User s Manual LTO R R www altoproaudio com Version 2 0 Dec 2002 English English COMPRESSOR LIMITER GATE ...

Page 2: ... apparatus and dis connect the power source Operating Conditions This apparatus shall not be exposed to dripping or spl ashing 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 Install in accordance with the manufacturer s instruct...

Page 3: ...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 Thank you very much LTO AUDIO TEAM Thanks for choosing LTO BK 2 0 Compressor Limter Gate and thanks for choosing one of the results of LTOAUDIO TEAM job and researches Our LTO BK 2 0 is the result of many hours of listeni...

Page 4: ...S 6 3 1 Expander Gate Section 3 2 Compressor Section 3 3 Dynamic Enhancer Section 3 4 The Rear Panel 4 READY TO ROLL 9 4 1 Expander Gate Section 4 2 Compressor Section 4 3 Limiter Section 6 TECHNICAL SPECIFICATIONS 13 7 BLOCK DIAGRAM 14 5 INSTALLATION AND CONNECTION 11 5 1 Mains Connection 5 2 Audio Connection 5 3 Rack Mounting 8 WARRANTY 15 ...

Page 5: ...k 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 di...

Page 6: ...se the volume during low passages and decrease the volume during loud passages Unfortunately even the Great Houdini would not be fast enough to monitor carefully the speed of the musical signal and it would be impossible to detect signal peaks and consequently levelling them out Manual control is therefore out of question The answer is AGC automatic gain control a device that will monitor the sign...

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Page 9: ...ed when compression is taking place 3 4 The Back Panel Pic 5 The Back Panel Layout Of The BK 2 0 13 12 15 14 16 OUTPUT INPUT TIP INPUT RING OUTPUT SLEEVE GROUND OUTPUT INPUT TIP INPUT RING OUTPUT SLEEVE GROUND CHANNEL 1 SIDECHAIN CHANNEL 2 SIDECHAIN AC INPUT 95 120V 210 240V6 0 50Hz Rated Power Consumption 8W FUSE 210 240V T100mAL 250VAC 95 120V 200mA 250VAC REPLACE FUSE WITH CORRECT TYPE ONLY SER...

Page 10: ...processor It simply cut off the entire signal below a certain set threshold The BK 2 0 is equipped with a new kind of expander the SRC Smart Ratio Control The ratio of the SRC is automatically adjusted according to the audio signal level In fact conventional expanders could easily cut part of the musical program with unacceptable result The gain changes become audible We have equipped the SRC with...

Page 11: ...aps etc a short attack time will be used These peaks are consequently carefully regulated by the compressor Sounds of other nature will get advantages if longer attack times are used Anyway our advice is always to begin the process with longer attack times Then you can start gradually to reduce the attack time IN the BK 2 0 the attack time can be set in a range of 1 to 200 milliseconds Output Hard...

Page 12: ... IN this way you will avoid undesired dynamic distortion But what about if you are mixing a program with a wide range of frequencies In this case you should choose a setting that would benefit the low frequency better Well life is not that easy for conventional compressor limiters Ok you handle an audio signal made by a wide range of frequencies and you have chosen a longer attack time But if are ...

Page 13: ...nput b In Line Connection Please see following drawing for details TIP RING SLEEVE TIP RING SLEEVE TIP RING SLEEVE TIP SLEEVE TIP SLEEVE TIP RING SLEEVE TIP SLEEVE TIP RING SLEEVE SLEEVE RING TIP SLEEVE RING TIP SLEEVE TIP Tip Ring Sleeve Tip Ring Sleeve Tip Ring Sleeve Tip Ring Sleeve Tip Sleeve Tip Sleeve Tip Sleeve Tip Ring Sleeve 1 2 3 1 2 3 1 2 3 Tip Ring Sleeve 1 2 3 Centre Centre Centre Scr...

Page 14: ......

Page 15: ...0 05ms to 4s 20dB From 20 to 20dB Interactive Expander Gate Variable from OFF to 15dB Dynamically controlled frequency correction Variable from off to 6 Bypass switch Programme dependent attack and release time Type Impedance Maximum input level Type Impedance Maximum output level Frequency response THD N 1kHz 4dBu IMD SMPTE 10dBu Noise Hum unity gain Noise Hum fully off Cross talk 20kHz CMR 1kHz ...

Page 16: ...15 7 BLOCK DIAGRAM Chart 8 Block diagram of the BK 2 0 ...

Page 17: ...TO of 1 year from the purchase date if you have completed the Warranty Registration Card in time 3 3 During the warranty service may repair or replace this product at its own option at no charge to you for LTO parts or for labor in accordance with the right side of this limited warranty 3 4 This warranty does not apply to the damages to this product that occurred as the following conditions Normal...

Page 18: ...audio 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 Copyright 2003 Sekaku Electron ...

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