Sound Performance Lab Kultube Model 2049 User Manual

Processed in this way, drums get more self assertion and sound ‚faster’.  

The best setting is not always easy to find, since you usually need to find a 
compromise. Very fast settings run the risk of producing audible distortions 
– especially in the case of low frequencies, since the compressor now tries  
to control each waveform rise. The corresponding control signal assumes a 
“saw-tooth” form which distorts the audio signal. 

To suppress this effect, you would have to again increase the attack time 

until the distortions no longer occur. In normal operation the Kultube attack 
control works exactly as just described. There is a unique feature of the 
Kultube however that greatly expands the compression possibilities by provi-
ding special technologies to achieve optimum results in all situations: the 
Progressive Time Control (PTC), which is described in the following.

Simply put, the Progressive Time Control (PTC) is an adjustable automatic 
process that works as follows.

The usual (rigid) attack control of a compressor functions, as described 

above, such that a resistance value can be varied within the controller circuit 
to determine the control response time. The main drawback to this, parti-
cularly when it comes to complex musical material, is that the setting only 
applies to a moment, but is not ideal for every moment. 

Automatic setting of the attack time (in response to the input signal) has 

the advantage of making the optimum setting for each moment. For this the 
changing of the resistance value that determines the attack times needs to be 
automated. A special circuit determines the momentary ideal attack time and 
sets the VCF appropriately. These times can vary between 20 µs and 980 ms 
and are set in fractions of a second.

This automatic process is thus a guarantee for perfect compression results, 

but the PTC in the Kultube goes even a step further: The attack control can be 
used to determine the intensity with which fast signal jumps are compressed 
in automatic mode. When you change the attack time using PTC, as for 
example when processing drum sounds, you can specify the handling of rapid 
signal jumps while at the same time ensuring that the attack behavior is not 
affected. A drum loop thus retains its original sonic character while still appea-
ring denser.