TL Aggro Overview
This sections explains the basics of analog compression, and how the TL Aggro works.
Compression is a common audio processing technique that is essential to many recording styles. A compressor is a specialized type of amplifier that acts to reduce the dynamic range between the quietest and loudest peaks of an audio signal. When dynamic range is compressed, this highlights quieter parts of an audio signal while taming the loudest parts. Heavy use of compression on percussion, instruments, and vocals is a staple in musical genres such as rock and pop.
Before the introduction of digital technology in the studio, compressors were typically designed around a set of analog components. Various compressor circuit designs are known for their distinctive sound and characteristics. Popular analog compressors are often designed around optical isolator, VCA (voltage controlled amplifier), or FET (field effect transistor) based circuits that produce the compression effect.
TL Aggro
TL Aggro implements a unique compressor topology based on a traditional analog FET design, with several updates for the digital age.
TL Aggro uses a reverse feedback system common to many analog compressors. In essence, this means that the compressor is not compressing the input signal but rather analyzing and compressing the already compressed output signal. Sound weird? It is. Reverse-feedback is a strange and paradoxical concept. It can lead to strange and chaotic behavior if not well-tamed. In fact, at least one well known and popular hardware compressor that uses a reverse feedBack topology becomes marginally unstable at extreme compression settings. Despite this sometimes unpredictable behavior, the reverse feedBack model produces a desirable and unique compression sound.
TL Aggro adds modern digital conveniences to the reverse feedBack model. Precise bass compensation provides for improved tracking of bass heavy instruments or a complete stereo mix. TL Aggro provides linked stereo operation to preserve stereo imaging as well as full side-chain support. A tube drive module adds additional tube-style distortion if desired.
TL Aggro uses a program dependent release which provides more natural sounding compression. In essence, the program dependent release works to slow down the release time of compressor so that it more smoothly rides the average loudness of the audio material.
The most unique feature of TL Aggro is its Threshold control. Most reverse-feedback compressors do not implement a Threshold control typical to non-FET compressors. Instead, they provide an input control that increases the amount of compression as the unit is driven harder. However, an input control adjustment is often less intuitive than a Threshold control.
Implementing a Threshold control into the operation of TL Aggro has two specific side-effects. At the extreme setting of a high threshold, high ratio, fast attack, and a slow release, TL Aggro can overshoot in compression and become “sticky” with a high gain reduction. Sonically, this sounds like “pops” in the output signal. In more technical terms, TL Aggro is becoming marginally unstable. In this scenario you can alleviate the problem by doing one or more of the following:
The second side effect is that for a given set of Ratio and Attack settings, the compressor has a finite range of available gain reduction. At some cutoff point on the Threshold knob, you might find that compressor ceases to apply anymore compression to the signal. To acquire more compression range, increase the Ratio slider, or alternatively increase the Attack speed.
The reverse-feedback model combined with the Threshold control and additional features like Bass Compensation and Tube Drive gives TL Aggro a wide range of compression styles once you understand how it operates. The ability to adjust threshold gives TL Aggro a distinctive advantage over traditional reverse feedBack designs, both in terms of functionality and sonic character.