This is a great bit of kit....I have the 100w version. Anyone out there with a valve or hybrid amp that they can't get the best sound from because you can't turn up beyond about 4 ? This lets you run the power tubes flat out and then just add a bit of pre amp dirt as required, allows the natural harmonics of the amp shine through which makes it sound fatter and more powerful. This is an absolutely indispensible bit of gear if you care about your sound and a fuckin bargain at this price.