User manual TL AUDIO A2

[. . . ] T L Audio User Manual Ebony Series A2 Stereo Processor TL Audio Limited, Letchworth, England. www. tlaudio. co. uk email: info@tlaudio. co. uk TABLE OF CONTENTS TABLE OF CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 WHY CLASS-A?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Compressors effectively turn down the loud bits and turn up the quiet bits, to achieve a more even and controllable level. Compressors are often judged by their ability to control the dynamics without creating noticeable audible side effects. Heavy compression can cause the signal to pump or breathe with the onset and release of the compression. Some compressor designs can dull the signal and lose the top end of the signal. The Ebony A2 is also capable of more severe compression based around the optional Hard Knee mode if this is desired. 9 There are other benefits of compression as well as just controlling the peaks and raising the quiet parts, applied properly, it can add punch and excitement to music, as well as fattening up sounds and creating a more professional sounding recording. With the Ebony A2, you have pristine Discrete Class A audio with the added benefit of a valve stage that can be activated into the input stage of the signal path, this then offers a warmth, clarity and presence just not obtainable with solid state or digital products. Overview of Compressor Operation. To operate the Ebony A2 successfully an understanding of each control will help to obtain the best results. If you are unfamiliar with the effect of compression it may help to adjust the controls to extreme settings and listen to the sonic effect. Generally compressors are used in two different ways: either to enhance the signal and control the dynamic range as unobtrusively as possible, or used more severely to specifically to create an effect. Threshold. The Threshold is the point measured in decibels that any compression comes into operation. The Threshold control is variable from +20dB in the most anticlockwise position to -20dB at the most clockwise position. Any signal below the Threshold passes through the unit unaffected; while signals above the Threshold are reduced in gain (and are thus `compressed'). This does depend on the Soft or Hard knee to some extent as the Soft knee is more gradual around the Threshold point. Unlike some compressors, the Threshold control on TLA units including the Ebony A2 starts at a `zero point' value in the counter-clockwise position, and decreases to a `minus' value as you rotate the control clockwise. The reason for this is as you turn the Threshold control on the Ebony A2 clockwise (i. e. towards the negative region) then the degree of compression will increase. We think this is logical, whereas the common method of turning the control `down' to achieve more compression is not - but beware, some other compressors may work in the opposite direction! Ratio. Once the input signal has crossed the threshold, the degree of gain reduction is determined by the Ratio control. The Ratio control is calibrated in decibels and is simply the change in output level that results from a given change in input level. An uncompressed signal will have a 1:1 compression ratio - every 1dB change in input level results in the same 1dB change in output level. A compression ratio of 1:3, for instance, means that a 3dB change in input level will only give a 1dB change in output level. For more severe compression, simply turn up the Ratio control. 10 The Ebony A2 offers a wide range of ratios from 1:1. 5 (gentle compression) through to 1:30 (limiting). Limiting effectively clamps the input signal at the threshold level no matter how much the signal is increased: this can be useful when trying to ensure that the signal doesn't exceed a certain level - for instance to prevent a digital recorder distorting through overload. Attack and Release. The Attack time sets how quickly the compression is applied once the threshold has been exceeded, and the Release time sets how quickly the compression is released (and the signal returns to normal) once the signal drops back below the threshold. The Ebony A2 Attack and Release controls each allow a choice of 2 switched positions either `Slow' or `Fast'. The speed of the Attack and Release should in general be able to work with the tempo of the signal. [. . . ] When gain reduction is taking place, you should notice that the output level is 16 reduced. By switching the compressor `in' and `out', you can compare the levels and the subjective sound quality of the original and compressed signals. With the compressor active, use the Gain Make- Up control to set the level so that when disabling the compressor, there is no level drop. This way you can A/B the original and compressed signals without the levels changing. [. . . ]