unless there's something wrong with it, i can't understand there being a power issue with the HD147, it's 300 watts IIRC. it's more or less a stripped down Vetta. i used the the Vetta II for a short time and power or volume was never an issue with it, it was going against a Brunetti XLII R-Evo!
does it have a half power function like the Vetta?