Hi Alessandro, and welcome. If you look in the Showcase section of this forum, you'll see that Elans don't all have the same control layouts. Perhaps the most common setup for an Elan is volume, pan, filter, and Q switch. Some are just volume, pan and filter. There's one that is volume, volume, filter. There are a couple that have the Europa controls; volume, pan, filter, Q switch, bass boost/cut switch, treble boost/cut switch. And there is one with Signature controls. So a picture would be helpful. The filter is a low pass filter; turning it sets the point at which higher frequencies are filtered out and only the lower frequencies are passed through. The Q switch provides a boost at the point where the filter is set.
