How does overheating protection work on the Torpedo VB-101?
The TORPEDO VB-101 embeds a temperature-monitoring system and an active security load to prevent any and all damage that might be caused to either user or product by overheating or by some improper use of the TORPEDO VB-101 with a guitar or bass amplifier.
When the TORPEDO VB-101 is OFF, the loadbox is not running, the Speaker Input is wired to a 168-Ohm security load.
When the TORPEDO VB-101 is ON, an active switch relay activates the loadbox so the amplifier "sees" the resistive loadbox. The DC impedance of the resistive loadbox is set around 8 Ohms.
When you are playing with your amplifier, the power sent to the TORPEDO VB-101 is turned into heat. The purpose of the high-quality Maglev fan placed at the back of the TORPEDO VB-101 is to extract that heat and cool the unit down.
At first, the fan will run slowly (or not at all), and it will start rotating as soon as the temperature is high enough. That way, you can operate in silence by choosing a proper amount of power (the output volume) on your amplifier.
Two things may happen while you are playing:
1- If the power is cut down on the TORPEDO VB-101, it will instantaneously switch to the security load, which is safe for your amplifier(*).
2- If the TORPEDO VB-101 is overheating, the unit will switch to the security load. A message appears on the screen "Overheating alert — Stop playing, let the unit cool down." The sound is switched off so you will notice the problem even if you are not in front of the machine.
Once on the security load, your amplifier will see higher impedance and will stop sending too much power. An amplifier can stand a higher impedance rating but we recommend bypassing the power amplifier as soon as possible. Let the TORPEDO VB-101 cool down to a proper temperature, and the warning notice will disappear as soon as the temperature is back to normal.
(*) You should not be playing when on the security load. Your amp is safe when simply powered up on the security load, but it is nonetheless unsafe to play on the security load over a long period of time.