Short Circuit Protection; Thermal Protection - VTC Pro Audio V64 Manuel De L'utilisateur

8. Limiter Switch
With the internal limiters activated, the V64' s gain is continuously adjusted to fit the signal within the available dynamic
range. Occasional clipping is permitted. The limiters will not only help to protect your system' s horns and tweeters,
but will automatically make the best use of the available dynamic headroom. With the limiters activated, all you need
to do is turn up the signal level until you start to see some clipping. The limiters will make sure that you are getting the
maximum clean power output at all times. Setting the switch to the IN position completely disables both limiters.
9. Protect LED
In the event of a shorted load or a load which is of too low an impedance for the amplifier to handle the PROTECT LED
will flash alternately on and off at about 3 second intervals. The sound may come on and off at ½ second intervals. In
this case, the fault is in the speakers or the speaker cables and should be located and remedied. No reset of the V64 is
required to restore proper operation. The PROTECT LED will stay on if the amplifier has overheated. Check the speaker
load impedance and any restrictions to air flow at the air intake or exhaust vents of the amplifier.

10. Short Circuit Protection

The V64 is fully protected against all possible passive load conditions. It can operate into a dead short continuously
without damage. (However, we don't recommend that you short your V64 "just for fun." Shorts do create a lot of stress
on the output devices). The output stage uses a unique triple slope VI-limiting scheme which is sophisticated enough
to remain inert during transient currents in excess of 100 Amperes and phase angles of more than 45 degrees, yet is
capable of protecting the output stage from damage due to accidental short circuits and improper loads.
11. DC Protection
In the unlikely event of the V64's outputs going DC, a thyristor circuit will short the output terminals and divert all
potentially harmful currents away from your speakers.

12. Thermal Protection

In the unlikely event that the V64 overheats, the signal will be sporadically cut off and the PROTECT LED will stay
on. The V64 is designed and tested to operate under "worst case" conditions without shutting down, so if you
experience a thermal shut down you should check for blocked air flow.
13. Cooling
The fan draws air in from the front and expels hot air through the rear vents. This is compatible with most installations.
Since hot air rises, the heated air forcibly expelled from the back tends to rise away from the equipment rack. This draws
cool air from the floor upwards into the front of the rack. In some cases where the rear of the rack is obstructed, it may
be necessary to install rack fans to aid cooling. If there are no obstructions, no secondary cooling is required.
14. Clip LEDs
The CLIP LEDS on the front panel will visibly indicate any signal excursion beyond the dynamic headroom of the
amplifier.
15. Reliability
The V64 is designed and manufactured by VTC Pro Audio. Each unit undergoes a thorough, temperature cycled
burn-in period, and each circuit is tested by both manual and sophisticated computer controlled equipment which is
capable of identifying any deviation from the design center parameters. The design of the V64 is conservative with
respect to the power handling capabilities of the output devices. The topology guarantees that thermal stress not
secondary breakdown will set the limits of operation, while the computer optimized heat dissipation system insures
that excessive thermal stress will not occur. VTC Pro Audio's reputation as a manufacturer of reliable equipment will
be further enhanced by the V64.
The V64 is not only suitable for use in both heavy duty touring sound reinforcement systems but also when high
headroom and low distortion are needed to fully reproduce the dynamic range and clarity of today's CD recordings.
It is built to survive grueling road conditions and constant 4 ohm operation. Its reliability in a fixed installation
running 4 or 8 ohm studio monitors is without parallel.
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