I've been using this very same attenuator (the weber) with my HRDx for about two years now, no damage to the amp (but I'm NOT using it to get bedroom volume with the amp cranked up :lol:), works fine for "light" attenuation (-6 to -9db I'd say), eats a bit of the tone and dynamics yes, indeed (repeat after me: there's NO silver bullet), but the result is still way better than trying to get the same volume _without_ it (specially on fenderish circuits). Very valuable tool at catalog price, and definitly a bargain at £80.