Operation Manual

11. Operation and performance
26
D SERIES Lake Operation Manual rev 3.0.4
11. Operation and performance
26
D SERIES Lake Operation Manual rev 3.0.3
channel Temperature Limiter (ATL) will engage at approximately 95% of the maximum allowable temperature.
When ATL is engaged, it will try to reduce the power output to avoid that the amp channel goes into temp fault,
i.e. muting. Limiting is removed when temperature falls below the ATL threshold.
11.3.8.2. Power Supply / DSP
A power supply (PSU) or DSP temperature warning or fault is indicated by the Temp LED.
• A warning is indicated by static amber LEDs
• Power supply Temperature Limit (PTL) is indicated by an amber LED
• A fault is indicated with static red LEDs
If the power supply temperature keeps rising after reaching the temperature warning threshold, the Power supply
Temperature Limiter (PTL) will engage at approximately 95% of the maximum allowable temperature. When PTL
i.e. muting of all channels. Limiting is removed when the temperature falls below the PTL threshold.
11.3.9. DC Protection
The DC protection is implemented, individually, on each power output to prevent damage to connected
loudspeakers or any D Series components. DC present at the output will cause the unit’s power output module
breaker to blow, causing a permanent hardware fault that prevents signal throughput. In this instance the channel’s
Amp LED will illuminate red and a service channel fault will be registered in the Lake Controller and CAFÉ status
views (D200, D120, D80 only). For the D40, D20 and D10, no audio will be heard from the outputs.
NOTE: A blown breaker in the power output module is not a user serviceable fault condition and the
unit should be returned for repair.
11.3.10. VHF Protection
The D Series includes protection circuits that detect Very High Frequency (VHF) content in the input signal. The
detection is amplitude–, frequency– and time–dependent. It is initiated from 10 kHz upwards and, if continuous
VHF signals are detected above the threshold for more than the attack time, the output for a D200, D120 and
D80 will attenuate the gain until the signal is below the VHF threshold. When this is done, VHF Warning is
displayed. If the signal is above the VHF threshold and the maximum of -12 dB of gain reduction is not enough
to take the signal below the VHF threshold, the signal will mute after 15 seconds, and retest the signal after
6 seconds. Note that the D40, D20 and D10 will go directly to mute upon VHF detection. When continues
normal operation.
This protection system recognizes only continuous VHF signals at high levels that will not appear in speech or
music. Any such content can therefore be considered as a fault condition. VHF protection is essential to avoid
damage to HF drivers. VHF protection is dependent on a combination of output power level and frequency.
Figure 11.4 shows a decreasing power threshold, from approximately 10 kHz upwards, which illustrates increasing
sensitivity of the protection system with frequency. When continuous output power above the threshold line is
detected, VHF protection becomes active.