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11

5. INSTALLATION AND  CONNECTION 

5.1 Mains Connection 

BK 2.0 is provided with dual voltage plug. You must check the power supply Voltage available in your 
Country before connecting the power cord in the wall outlet. Please see Page, paragraph 12 for further info.

5.2 Audio connection 

The BK 2.0 Compressor/Limiter/Gate is equipped with balanced XLR connectors as well as 1/4" pho ne jack and can 
be connected with other units in different ways to support a vast range of applications without experiencing a signal 
loss.

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 longer attack time is advisable to process low frequencies while shorter attack time is preferable 
for high frequencies. 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 using your BK 2.0 as a limiter the 
fast high frequencies will pass through untouched because the attack time is too slow and such transients could 
cause distortion when the unit is connected to broadcast devices or taper recorders.

The solution in BK 2.0 is represented by our Smart Gain Control (SGC) limiter circuit. The curve in bold is the 
output signal and the dashed curve above it is the input signal. The area in between the two is the amount of 
gain reduction.

The unit will activate the limiter when the signal exceeds the threshold for more than 15 microseconds. Then 1 
second after that the signal is below threshold again, reduction goes back to 0dB and in this case input and 
output signals are again identical.

Chart.7: SGC characteristic of the limiter section

Peak Limiting 

6ms

15ms

Level

Program Limiting

Input 

Release

Output

approx. 1 s

Threshold

t/ms

30

20

10

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...

Page 7: ......

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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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