Sound Performance Lab RackPack 2710 - Manual (Page 14)

14
RackPack
External Power Supply
The external power supply offers fundamental advantages over internal power supplies:
Properly installed, transformer hum and interference should never be an issue and the unit
should deliver clean, clear audio.
In addition to that, internal circuitry is free from AC power which could negatively influence
especially sensitive modules such as preamps.
The 100 VA transformer is generously proportioned to ensure plenty of power in any situation
and proper current for the various circuits.
Entirely new circuit designs were developed to process the various direct currents. The +/-
18 V current, for example, utilizes a discrete voltage regulator with barely measurable noise.
High-speed rectifier diodes and large capacities ensure sufficient current to process even the
most powerful impulses. In addition, most currents are stabilized using 400 V/100 nF MKP foil
condensers to ensure plenty of current for fast transients.
48 V phantom power is also processed using discrete, low-noise voltage regulators and fed
directly to the microphone conductors through two resistors.
Placement Of The External Power Supply
Do not place the RackPack on top of the external power supply or the power supply on top of
the RackPack. Place the external power supply on a level and stable surface only. We recom-
mend a distance of at least 50 cm/20 inches to avoid any interferences between the trans-
former of the external power supply and the RackPack or other devices.
Choose a place that is easily accessible so that you can switch off the external power supply
quickly in case of an emergency.
Please mind the notes under “Power Connection” on page 8.
On And Off
In switching on and off, you do not need to follow any particular sequence with connected
devices in the periphery of the RackPack. There is, however, the general rule for a chain of
devices in the audio processing to always turn on power amplifiers last and to turn them off
first. If specified sufficiently you can also switch the external power supply through a multi-
way connector or other main switches.