yeah I use an attenuator with my Lisa III, has to be a really nice one or yeah it does impact on the sound in a bad way. I use a cable type with vishay S102 'NUDE' resistors (100ohms) I find it actually impacts on the sound in a positive way, with LESS components in the signal path actually. since some pots are comprised of a series of resistors and not always of high quality. so replacing them with one of the highest quality works for me. not saying the pot on the lisa is bad; its quite balanced actually, but I find the sound opens up a bit with the pot more open.