D&b Audiotechnik D12 Hardware Manual - page 25
6.2.2. Operating
conditions
The following diagram shows the thermal operating range within which
the technical data will be maintained. The operation beyond this range is
possible for a short time and for thermal reasons this will trigger the
amplifier protection circuit into thermal overload.
0
5
10
15
20
25
30
35
40
45
0
100
200
300
400
500
600
700
800
900
Ambient Temp. in °C
Max. average output Power [W]
Fig. 20: Average maximum total output power vs. ambient
temperature
As explained in section 6.2.1, a worst case signal with a CF of 2.4 is
producing 1/3 of the rated sine output power or 400 watts at 4 ohms
per channel (800 watts total). The thermal management of the D12 is
designed to deliver this power for an unlimited amount of time within an
ambient temperature of up to 30°C (86°F). With higher ambient
temperatures, the maximum average ouput power that can be delivered
without entering thermal protection, is reducing linearly as shown in the
diagram.
When using the D12 at its upper temperature limit of 45°C (113°F), the
maximum continous output power is 500 watts total or 250 watts per
channel. Again referring to section 6.2.1 - (Tab. 7) - the unit will work
properly with e.g. 400 watts total when either running 4 ohms loads
when the signal has a CF of 3.5 or running 8 ohms loads if the worst
case signal with a CF of 2.4 needs to be handled.
The maximum possible output power of 2 x 1200 W at 4 ohms, which
for thermal reason could only supplied in a short term (within minutes), is
unaffected by the ambient temperature.
6.2.3. Mains
supply
Number of devices per phase conductor when full output power is
required.
Mains supply
Number of devices
230 V / 16 A
Max. 2
115/100 V / 15 A
Max. 1
Tab. 8: Mains supply and number of devices
In the USA and Japan we recommend the operation over two phase
conductors (phase to phase - 240/200 V) or the use of mains leads with
a much higher cross section (min. 4 mm
2
/ AWG 12).
D12 Amplifier, Hardware manual
(2.0E)
Page 25 of 32