It depends on the tuner. Some tuners can benefit from simple tweaks, others need more work. A simple tweak would be to disconnect an unused something like an antenna outlet. A more involved tweak would be replacing components in the IF strip. Don has experience with many tuners. If anyone is interested email me and I'll send you a before and after of what he did to my Accuphase performance-wise. Don's kind of like a Dr. He needs to examine and apply his experience before he can apply science. But, he doesn't need to give away his secrets!