Krell Industries 400 Stereo Amplifier User Manual


 
23
Evolution DC Protection Circuitry/Using Tube Preamplifiers
The high DC output of tube preamplifiers may exceed the active DC protection
circuitry of the Evolution amplifiers. Excessive DC level in a signal can damage
amplifiers, loudspeakers, or both. The single-ended inputs of the Evolution ampli-
fiers are capacitor-coupled and DC does not pass through. Therefore, if connect-
ing a tube preamplifier, use the single-ended inputs only. For more information
about DC protection circuitry features,
see Error Codes on page 26.
Connection Steps
Position the amplifier where you intend to use it in your system.
The following steps describe how to connect an Evolution amplifier to your sys-
tem:
1. Turn off all power sources and components before connecting inputs and out-
puts.
2. Neatly arrange and organize wiring to and from the Evolution amplifier and all
components. Separate AC wires from audio cables to prevent hum or other
unwanted noise from being introduced into the system.
3. Connect the outputs of your preamplifier to the appropriate CAST (4), balanced
(6), or single-ended inputs (5) on the Evolution amplifier.
Note
Connect the u-shaped jumpers between pins 1 and 3 of the XLR connectors when
using single-ended inputs.
4. Connect the loudspeaker cables to the loudspeaker binding posts (7) on the
Evolution amplifier. The binding posts accept spade lugs only. Take care to
observe the correct polarity when making connections: The positive (+) output
connects to the positive input of the loudspeaker. The negative (-) output con-
nects to the negative input of the loudspeaker.
5. Connect the supplied AC power cord to the AC power cord receptacle (9).
6. Plug the AC power cord into AC power.
Note
Use only the power cord provided with the Evolution amplifier to make the connection
to AC power. Operation with a power cord other than the one supplied by Krell could
induce noise, limit current, or otherwise impair the ability of the amplifier to perform
optimally.