TL Audio A4 - Manual (Page 3)

3
INTRODUCTION
Thank you for purchasing the Ebony A4 Summer. 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. A combination of supreme quality, unrivalled
sound and stylish aesthetics - this range offers superior analogue processing to
accompany a digital world.
The Ebony Series A4 Summer is a 16 channel unit, accepting balanced or unbalanced
line inputs, switchable between +4 and -10dB, via TRS Jack or DSUB connector.
Each channel has individual Pan control, and there is also master gain control and
balanced insert points with bypass. A tube stage may be switched into the master
signal path, with variable drive control.
The block diagram of the processor is shown in fig.1. A discrete Class A electronically
balanced input is used, delivering superior audio performance with very low noise,
and wide bandwidth
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. This even harmonic distortion gives the colour
and sound that tubes are famed for. The tube stage can be selected or bypassed as
required.
A VU meter is provided, which can be selected to either input or output signals. The
meter is also provided with a “+10dB” switch, which keeps the reading on the scale
when driving a high level out (to a DAW, for example). In the +10 mode, 0VU is
calibrated as +14dBu out.