14
Operating Manual - Powerflex Multi-Channel Power Amplifier
11.2
Distorted Sound
1.) Clip LED is flashing regularly
Amplifier is being overdriven. Turn down the in-
put level control, or reduce the output level from the sig-
nal source.
2.) Clip LED is not flashing at all
Amplifier input signal may be exceeding input
headroom, which is greater than +12dBu, or 3.4V rms
(measured using continuous 1kHz sine wave). Incoming
signal level higher than +12.8 dBu will cause distortion in
the amplifier. Turning down the input level controls will
not eliminate distortion if the input headroom is exceeded.
Turn down the output level of the device driving the am-
plifier instead.
Additionally, an input signal may already be dis-
torted before it gets to the amp. Check to see if a piece of
equipment in the signal chain before the amp is clipping.
For best performance, the amplifier should be operated with
input levels fully CW. Also check for damaged speaker
drivers that could cause distorted sound.
12.
POWERFLEX DIMENSIONS
Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Channel 6
Pr ot ect
Therm al
Cli p
Signal
Po wer
Powerflex
6250
16.94"
13
.5
4"
5.
19
"
4.
7
5"
2.
25"
18.5"
19"
2.25"
13
.1
8
"
1.
25"
11.3
Hum or Buzz Noise
Be sure that the power cord’s 3-prong plug is con-
nected to a properly earth-grounded outlet. Lifting the
grounding third prong may not improve hum or buzz and
can create a potential shock hazard.
Hum is usually caused by ground currents flow-
ing between different pieces of equipment. Ground cur-
rents can be minimized by using a single point AC ground
for the sound system, and by using balanced connections
with quality cable throughout the audio path.
Buzz, as well as certain audible high frequency
tones, can be caused by environmental emissions such as
lighting dimmers, neon lights, or computer equipment. Use
balanced connections, and try moving the amplifier, wir-
ing, lighting, or other equipment to different locations to
isolate the source of the noise.
Sections 3.3, 5.3, 7.1, and 7.2 further discuss is-
sues related to grounding and noise problems.
