This is the 50 W version of Ted Weber’s Mini Mass Power Attenuator. It is flexible with impedances and works with 4, 8, 16 ohm loads, treble compensation, MASS bypass, line out. The MiniMASS employs an actual speaker motor for realistic interaction between the attenuator and the output circuit of the amplifier. The attenuation is continuously adjustable from zero to over -50db. By turning the speaker control to minimum (maximum attenuation), the unit may be used as a dummy load for testing or for DI use.