SECTION 3 — OPERATING INSTRUCTIONS
3-1 Bargraph Description
The Bright-VU meter display contains two multi-
LED bargraph displays mounted one above the other.
The top bar shows left channel and the bottom bar
shows right channel. The 20 segments are arranged in
four color groups. The -35 to -1 dB segments are
green, the 0 dB segment is yellow, the +1 to +3 seg-
ments are orange and the +6 to +18 dB segments are
red. Average (VU) levels are shown as a solid bar
while peak (PPM) levels are shown as a single dot.
3-2 Display Ballistics
In the PPM mode, the display has essentially 0 at-
tack time and a 2.8 second per 24 dB release time. In
average mode, the display has an attack and release
time of approximately 300 milliseconds per 20 dB.
These ballistics conform the international standards
with the exception that the Bright-VU peak attack time
is slightly faster.
3-3 Using Alignment Tones
The Bright-VU always displays the actual meas-
ured values of the input signal. If a constant level sine
wave is applied to the meter, the PPM dot will be about
3 dB above the VU bar. This is due to the difference be-
tween the average and peak value of a sine wave. The
size of the VU to PPM difference is a function of signal
wave shape and the only signal that has the same VU
and PPM reading is a square wave.
3-4 User Maintenance
The chassis and display windows of the unit may be
cleaned using a mild detergent or isopropyl alcohol
and a soft cloth. Do
NOT
use abrasive cleaners or aro-
matic solvents to clean the Bright-VU meter units.
* * * * * * * * * * WARNING * * * * * * * * *
The inside of the Bright-VU contains no controls or
user serviceable parts. The cover should only be re-
moved by competent technical personnel capable of
servicing this type of equipment. Hazardous voltages
exist on the underside of some circuit cards.
* * * * * * * * * * * * * * * * * * * * * * * * * * *
Logitek will be happy to provide further information
for servicing the unit. Please contact the factory or
your Logitek dealer for further information.
3-5 Resetting the Program
The Bright-VU contains software that executes on a
programmable DSP integrated circuit. If the processor
memory becomes corrupted, the meter may function
incorrectly or fail to operate altogether. In most cases,
an independent watchdog circuit will notice that the
meter is working incorrectly and restart the system.
The processor can be reset manually by turning
the power off for fifteen seconds and then back on
again.
** Bright-VU Instruction Manual **
Page 7
