80dB – Telephone ringing
90dB – Pneumatic drill
100dB – Power mower
120dB – Boom box in car
130dB – Pain level
140dB – Jet plane 30m overhead
• It is important to know that a 3dB increase will double the sound level. The human hearing only recognizes a
doubling of the sound level when the noise level is increased by 10dB. Hearing loss does not depend on the
sound level but on the noise level and starts way before than the pain level.
• Many a one deceives himself by thinking that noise is something you can get accustomed to. Nothing is further
form the truth!
• The reason why some people have got accustomed to a certain noise level and are no longer disturbed, is that
they have already suffered hearing loss. The damage makes the hearing insensitive to the frequencies forming
the loudest part of the noise. Getting accustomed to noise does not mean anything other than trying to get along
with hearing loss in everyday life. Hearing loss cannot be recovered and can only be compensated with hearing
aids. Subjectively, hearing loss feels like having dampened ears. This effect weakens with time but loss in hearing
sensitivity is permanent.
• In order to relax your hearing sufficiently, the noise level should not exceed 70dB for 10 hours. Higher noise levels
during this relaxing period can prevent relaxation and promote permanent hearing damage or hearing loss.
WARNING: Protect your ears if you want to prevent hearing damage!
7. Description
Features:
• outstanding tone
• original appearance and precise manufacturing
• protection circuits
• limiter to prevent speaker damage when the amplifier is overloaded
• high audio frequency performance
• amplifier-on time delay and amplifier-off mute protection protect the speaker from transients
a. Front Panel (fig. 1)
1. Air inlet
Cool air is inhaled from the front and hot air is exhausted from the rear to assure that the amplifier and cabinet
are cool inside.
2. 20-step level control for channel A
In bridged or mono parallel connection mode, only this knob is used.
3. Signal LEDs channel A
The green LED indicator lights to indicate the corresponding level. When the red LED (CLIP) indicator lights, it
means that the amplifier is distorted.
VPA600MB
5
VELLEMAN