MicroMASS ™
Mobility Analog System Simulator
2lb   (.9Kg)
4" (10.16cm) wide, 5" (12.7cm) deep, 3-1/2" (8.89cm) high.
15 watt -- $85


Instructions for Use
1. Disconnect speaker from amp
2. Connect speaker to output of MicroMASS
3. Connect amp speaker output to input
of MicroMASS with a short cable.
The cable must have the appropriate connectors for your amp.

(I know the picture shows black, but that is the old model, and I will get a picture up of the red one just as soon as possible)

MASS with 15 watt rating. 8 ohms. May be used on 4, 8, and 16 ohm amplifiers. Includes MASS bypass, and line out. This is one of our most unique MASS units in that it has two power level controls, one for the bass-mid frequencies and one for the upper mids-treble frequencies. They may be adjusted independently for the best tone at all levels of attenuation. These controls affect the actual signal going to the speaker, not just a line out signal like in our other units. So, it is like having high level tone controls. The controls are very effective and the tonal combinations are virtually infinite. Because a MASS motor is employed, a more realistic interaction between the attenuator and the output circuit of the amp occurs. The attenuation is continuously adjustable from zero to over -50db using the attenuation controls. Like all Weber attenuators, setting the attenuation controls to minimum (maximum attenuation), allows the MicroMASS to be used as a dummy load for testing or for DI use.

Please read and consider the following prior to ordering an attenuator:
(The following text is reprinted with permission from Eurotubes http://www.eurotubes.com/euro-y.htm)

Here are some facts to consider when using an attenuator. Attenuators do work. They are not the cause of transformer failures. An attenuator can only simulate two out of the four components that are involved when you crank up an amp. The four components are #1 preamp tube distortion, #2 power tube distortion, #3 speaker distortion and #4 the physical movement of air that your speakers produce at high volumes. So the two components missing are speaker distortion and the physical movement of air and these are huge components! So if you’re playing at moderate volumes and just want to tame the amp down to get a bit of power tube breakup then an attenuator is a great tool, but do not expect to be able to dime your amp and then use any attenuator on the market to get the exact same sound from your amp at whisper quiet volumes. You can't get there from here. You would be better off with a one watt amp.

So, now some answers. Catastrophic power tube failure will cause transformer and screen grid resistor failures. The reason you will read and hear horror stories from unknowledgeable attenuator users is because they do not understand how attenuators work and the stress they put on your tubes.  If in fact, a player chooses to run his amp cranked all the way on and attenuate the volume down to a whisper, then in most cases power tubes will only go a few months. Power tubes will die in one of two ways. The first and most pleasant is by simply fading and dying. The second and more popular way is to go out in a blaze of glory which is what I referred to above as a catastrophic failure which can and most often will, take out screen grid resistors.

Tubes sound great when they are really working hard but the harder you work them the faster they wear out. If you understand this and either use the attenuator sparingly or change your tubes regularly then your amp will not suffer damage.

If you are going to dime your amp out and attenuate it down to very quiet volumes then we recommend using an attenuator that is rated for twice the power of your amp's rated output.

If you are simply going to dial an amp up to where it starts to breakup in the clean channel and then knock it down a few dB so the club owner and the sound man are happy, then using a 50 watt attenuator for a 50 watt amp will be ok.