Is there any risk using my tube amp with the VB-101?

A full tube amp cannot be used without an output load such as a speaker.
The VB-101 includes an 8-ohm load, which replaces the speaker and dissipates power, allowing you to use the full amp without any risk.

However, the fact that the VB-101 is a very silent unit should not make you forget that your amp is still working in a normal way. Turning up the volume of your amp yields high level of output power! Most amplifiers are not designed to work at a very high level of power. In order to avoid all risks, we recommend not using your amplifier near its maximum volume. Ask your amplifier's manufacturer for more information.