Lab.gruppen E 8:2 - Manual (Page 14)

13. Operation and performance
14
E SERIES Operation Manual rev 2.0.0
13. Operation and performance
13.1. Introduction
The following sections provide comprehensive information on amplifier connection, setup, operation, and
performance. The detailed information included here is essential to realizing the full functionality of the
E Series amplifiers.
13.2. Operating precautions
• Make sure that the amplifier is off or in standby mode before making any input or output connections.
• This amplifier is equipped with a Universal Power Supply that handles nominal voltages from 100 V to
240 V @ 50 - 60 Hz. It will turn on between 85 V – 264 V. For full power it requires 100 V or more, but it
will remain functional at voltages above 60 V with reduced output power.
13.3. Signal flow and headroom
All E Series amplifiers have the same signal flow and feature set, differing only in the ability to deliver power to the
loudspeakers.
Balanced input
terminal
(17.2 dBu
headroom)
Attenuator
Bridged amplifier
(Gain depends
on RSL)
Rail Sense Limiter
(4 dBu for full
output Voltage)
High pass filter
(2 Hz / 50 Hz)
Loudspeaker
output terminal
This block also
implements the
protection
Clip, Thermal &
Rail sense
On all E Series amplifiers, the input stage has a relatively high sensitivity of 4 dBu (1.23 Vrms) for full power.
However, the input can handle signals up to 17.2 dBu without clipping the input signal path. The amplifier applies
low-distortion limiting if the input signal exceeds what is required to deliver full power. If compression isn’t desired,
use the input attenuator to trim the sensitivity. E Series amplifiers easily achieve a high SPL when driven with
sources capable of 10 or 20 dBu output, such as professional mixing consoles or DSP units.
However, consumer sources such as a CD player or an MP3 player will have a lower output, typically -10 dBV or
-7.8 dBu. This is not sufficient level to realize full power from an E Series amplifier. In this scenario, the user can
get closer to maximum power output by putting the mode switch in the 70 V position without risk of delivering
excessive power, even into a 2 or 4 ohm load.