Is a load resistor necessary when operating the BluBOX on a classic tube amp?
Yes, this is essential with classic tube amps! Traditional tube amps always need a load, in the form of a speaker cabinet or a load box. Under no circumstances should they be operated without a load, as this can damage the output transformer. The BluBOX does not represent a load resistance: it is a pure DI box with speaker simulation.
Therefore, a load resistor (speaker cabinet, load box) must always be connected to the SPEAKER THRU of the BluBOX when the BluBOX is connected to the SPEAKER OUT of a traditional tube amplifier.
Good to know: The AMP1 is an exception to this rule, because it can be operated without a loudspeaker or load box connected. The AMP1's unique, innovative power amplifier is ideally suited to delivering all sounds - even fully turned up to saturation - without a connected loudspeaker or load box.