Velleman VPA2100U1 - Manual (Page 5)

VPA2100U1 Rev. 01
29/07/2011 © Velleman nv 5
An Overview on the Different Noise Levels
10dB – Heartbeat
25dB – Whisper
40dB – Average home
50dB – Light traffic
60dB – Normal conversation
70dB – Vacuum cleaner
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
recognises 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. 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
8. Description
Refer to the illustrations on page 2 of this manual.
a. Front panel (fig. 1)
1. Power switch
To turn the unit ON or OFF, press this button. Before turning ON the amplifier check all
connections and turn down the level control. A momentary muting is normal when turning the
amplifier ON or OFF.
CAUTION: Always turn on your amplifier last, after all your other connected equipment, and
always turn OFF your power amplifier before your other connected equipment.
2. Power LED indicators
These LEDs illuminate when the power is turned ON.
3. Limit LED indicators
These LEDs illuminate if any section of the power amplifier’s input are within 3dB of clipping.
Occasional blinking of the LEDs are acceptable, but if they remain on more then intermittently
you should turn down the level on the amplifier or reduce the output level of the preceding
component to avoid audible distortion.
4. Signal LED indicators
These LEDs illuminate to confirm the presence of an input signal greater than 100mV at that
channel of the amplifier.