TL Audio A3 - Manual (Page 4)

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INTRODUCTION
The TL Audio Ebony Series of audio processors are a sleek looking range of discrete
Class A processors designed to heighten your audio experience; they use signal paths
constructed from discrete transistor “Class A” circuits, with switchable variable drive
tube stages, putting you in control of how ‘creamy’ or how ‘cool’ your unit sounds.
These techniques provide very high quality, uncoloured audio, with the option to add
valve warmth at the touch of a button.
Hand assembled in England to the highest standards, the Ebony uses stylish, quality
chrome knobs together with a high gloss black finish to make the exterior look just as
smooth as the circuits sound. The Ebony Series have all the features you come to
expect with TL Audio, including balanced I/O, multi input options, analogue VU
metering and intuitive, precise controls. All units are also compatible with the TL
Audio DO-2 digital SPDIF interface for easy digital connectivity with high quality
conversion. A combination of supreme quality, unrivalled sound and stylish aesthetics
- this range offers superior analogue processing to accompany a digital world.
The Ebony Series A3 Processor is a single channel unit, accepting mic, line and
instrument inputs. Processing includes gain and phase control, compression and
equalisation. A tube stage may be switched into the signal path, with variable drive
control.
The block diagram of the processor is shown in fig.1. A discrete Class A electronically
balanced mic input amplifier is used, delivering superior audio performance with very
low noise, low distortion and wide bandwidth. The mic input is suitable for low
impedance (150-600 ohm) microphones, with a gain control range of +16 to +60dB.
Front panel switches provide 48V phantom power, and 30dB pad for high output mic
applications.
The front panel mounted jack socket is suitable for a variety of sources, including
electric guitar, acoustic pickup and keyboard. The instrument input has high/low
switching, and a dedicated valve input stage.
Phase reverse and high pass filter switches are provided; affecting whichever of the
mic, line and instrument inputs are selected.
The tube stage has a variable drive control, with the signal level indicated by the
variable intensity “Drive” LED and “Peak” LED. Use of this feature typically
introduces 1% to 10% harmonic distortion, predominately second harmonic, without
changing the output level from the unit. The tube stage can be selected or bypassed as
required.
The Compressor has continuously variable threshold, ratio and gain make-up, and
switched settings for hard or soft knee and fast or slow attack and release times.