Dual Loadbox 2 x 8 Ohms. The Palmer PLB2X8 is a dual-channel, strictly reactive load (load box). A load box is a substitute for a speaker. It ensures that tube amps are connected to the correct load on the output, thus eliminating the risk of amplifier damage. The PLB2X8 is a perfect addition to speaker simulators that do not have a built-in load (load box) (for example: PDI09, PGA05 and PDI05). The PLB2X8 is also useful in conjunction with guitar amps that have a line out or filter out connection. In this case, the PLB2X8 permits silent operation of the amplifier with simultaneous use of the line/filter output.