Pat, it couldn't help unless your 705 wasn't adequately powering your setup for your use pattern. This is unlikely unless you're playing at extremely high sound levels in a very large room. At a comfortably loud average sound level your speakers use 1 watt or a bit less; brief peaks use much more, of course, depending on how wide the dynamic range of the material being played is. The 705 is a quite powerful amplifier and handles most use situations easily, so there's no good reason to spend more on a separate amplifier.
