Topp Music Gear TCL Series, User Manual

Chart

. 7 SGC characteristic of the limiter section

 INSTALLATION AND  CONNECTION 

      Mains Connection 

TCL-2 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 Page9, paragraph 22 for further info.

      Audio connection 

The TCL-2 Compressor/Limiter/Gate is equipped with balanced XLR connectors as well as 1/4" phone jack and 
can be connected with other units in different ways to support a vast range of applications without experiencing a 
signal loss.

    Gain Reduction Meter

This consists of 12 LED on the front of the TCL-2. 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

 Peak 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 using your TCL-2 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 tape recorders. The solution in TCL-2 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.

Peak Limiting 

6ms

15ms

Level

Program Limiting

Input 

Release

Output

approx. 1 s

Threshold

t/ms

30

20

10

12