TL Audio A1 - Manual (Page 11)

10
Tube Stage Drive and Peak LEDs.
These LEDs indicate the drive level to the tube, or valve, stage. The Drive LED is a
variable intensity indicator, starting to glow when the tube harmonic distortion is
around 1%, and being fully illuminated at approximately 5% harmonic distortion. The
distortion is predominately second harmonic, unless very high drive levels are used, in
which case the tube is eventually pushed into harsher saturation, indicated by the tube
Peak LED.
Output Peak LED.
Each channel has an output Peak LED adjacent to the VU meter. These LEDs
complement the average reading VU meter, and are useful for monitoring the output
prior to sending to a DAW, for example. The Peak LEDs illuminate at an output level
of +19dBu.