50 Hz High-Pass Filter; Auto Power Down / On (Apd / Apo) Scheme; General Purpose Input / Output (Gpio) Facilities; Unpacking And Visual Checks - Lab.gruppen E 4:2 Operation Manual

6. Unpacking and visual checks

5.2.4. 50 Hz high-pass filter

Each channel has a switchable 50 Hz high-pass filter. In the default full-range position the amplifier has a flat
response with a -3 dB point at 2 Hz. When engaged, the filter rolls off low frequencies (12 dB/octave) for greater
efficiency and reliability in, for example, 70 V high-impedance systems where the removal of very low frequency
content may be desired. The filter can also be used if desired when the output channel is connected to low
impedance loudspeakers that are unable to reproduce deep bass frequencies.

5.2.5. Auto Power Down / On (APD / APO) scheme

To comply with Energy Star 3.0 requirements, all E Series amplifiers incorporate an APD scheme with power
consumption below 1 W in sleep/standby mode. The E Series will go to standby mode after 20 minutes without
input signal.
E Series also incorporates an APO functionality that restores full operation less than two seconds after signal is
applied to either of the inputs. Section 12.2 describes the threshold that is used.

5.2.6. General Purpose Input / Output (GPIO) facilities

The GPIO connections allow seamless interfacing with many third-party control and power sequencing systems.
Functions are optional; the amplifiers will operate normally when GPIO is not connected.
The General Purpose Input (GPI) controls the power state via external contact closure as follows:
• It reacts to a transition from open to closed by forcing the unit to the on state. The APD function will still apply,
and the on state will be retained after a power cycle.
• It reacts to a transition from closed to open by forcing the unit to the standby state. This will also disable the
APO until it is turned on again.
The General Purpose Output (GPO) is an internal contact closure that, when closed, indicates the unit is on and
both channels functional (neither muted due to high temperature). Open indicates that the amplifier is either in
standby or protective mute is activated in one or both channels.
6. Unpacking and visual checks
Every Lab.gruppen amplifier is carefully tested and inspected before leaving the factory and should arrive in perfect
condition. If any damage is discovered, please notify the shipping carrier immediately. Save the packing materials
for the carrier's inspection and for any future shipping.
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E SERIES Operation Manual rev 2.0.0