My NAD 370 has them, but i'm not sure if it's advisable to use them or not. I've heard rumours that they dilute the sound quality. The reason i'm asking is because my system is just slightly too bright in the treble and lacking a little in profound bass on certain CD's. This is probably caused by the marantz CD6000 OSE player being detailed and ever so slightly bright coupled with a fairly aggressive sounding amp and QED silver anniversary cable. Also the b&w 603 S3 speakers have one fault and that's the treble: It's a bit crude in comparison to the flawless mid range and tight bass. Apart from this, the system sounds great. So do i adjust tone controls, or invest in some subtler cabling? Cheers.