Great working condition, lightly used, studio use only, kept in a smoke free environment.

This attenuator has two knobs for tonal control. The main volume is controlled by the large Speaker knob. Then to control the treble, use the Treble Compensation knob. The treble control is always dependent on the main volume control. Be aware that the higher the setting on the main knob, the less the effect of the treble compensation. For instance, if you turn the main knob all the way to 10, you’ll notice very little change in the tone as you turn the treble compensation from one end to the other. The line out signal is dependent on your amplifier settings.

200 watt MASS with a moving voice coil speaker motor for the load. This unit is impedance swamped to protect the output of your tube amp, and may be used with 4, 8, and 16 ohm amps. Includes adjustable Line Out, System Bypass, and Variable Treble Compensation. Volume level is continuously variable to over 50db of attenuation.

Like all Weber attenuators, setting the speaker control to minimum (maximum attenuation), allows the MASS 200 to be used as a dummy load for testing or for DI use.

IMPORTANT NOTE ABOUT HIGH GAIN AMPS*: *if you have a Fender or similar amp, and play with cleaner tones, this part does not apply to you. High gain amps such as Marshall or clones (with heavy distortion) are hard on attenuators. Unfortunately, an amp’s volume dial is not a good indicator of how much power is being produced.  Many amps can reach full power at 3 or 4 on the volume dial, so it is a good suggestion to get an attenuator with 4x the power handling. For example, if you have a 50w high gain amp, you should opt for the MASS 200. If you have a 100w amp, you should still go with the MASS 200 but you should not crank the amp. 

1) do not attenuate too far down. this puts a lot of power through a very small section of the volume rheostat which can cause it to fail

2) also do not turn your amp all the way up.  even if you’re just knocking a little off the top with the attenuator, it’s a good idea to keep the amp somewhere in the middle at most.  it’s best to find the lowest volume on the amp that is the acceptable tone to you, and then use the attenuator to bring it the rest of the way.