Did you know the Vintage 16 guitar combo amplifier and the VT16 head version have an internal dummy load? When you want to play your amplifier without a speaker load you need what is called a dummy load. With tube amplifiers you have to load the amplifier (connect speakers) or you may damage the output power tubes. The output power tubes use the output transformer to "transform" the speaker's impedance to correctly load themselves to work properly. If the amp is running and the speakers are not connected the output power tubes are unloaded and the amplifier can become unstable. The dummy load replaces the speaker’s impedance for the output transformer and completes the circuit, so your amplifier is happy and stable. This is great for headphone use and recording where a direct signal is taken from the amp's line output. When you need tube tone in a quiet situation look to the Vintage 16 series.