Small magic item that allows you to use the head on high (as it should normally! Order to hear the richness, the texture of the head) but low volume as a share of the power in the Hot Plate and not the baffle. As a result you can use your head anywhere and a first home!
Personally I tried it from a dealer in my test amp before purchase and it really does! sound of an amp (in this case was the head VHT and Brunetti) pushed to block has nothing to do with the sound of an amp minimum power: the sound is full, total, more than this. . Without the Hot and low volume it seems that the sound is cut off!

In addition it features a built-in noise reduction, a line-out and the ability to connect two speakers the same time and in addition they have a beauty to fall.
It is truly an essential accessory for those who want the Sound anywhere.
THD Hot Plates and are relatively difficult or impossible to find in France, I know only one dealer who proposes them, they are based in Toulouse and the company called Pi-amp
In terms of price / quality ratio is excellent and I even bought one for me