Why no batteries?

It seemed a simple and obvious question, but I couldn't get an answer out of Ron Sutherland. Why did his new 20/20 phono preamp use an AC power supply instead of batteries? I asked directly, I asked repeatedly, I tried framing the question in different ways, all to no avail. Did the AC supply make it sound better? Was it less expensive to build? Were potential customers turned off by having to replace batteries once every year or two?

The M5i, basically a two-way bookshelf version of the 21½-way M16i, has the same tweeter, woofer, and footprint as the larger model, less its larger cabinet and second mid/woofer, and incorporates all of the i-series updates included in the M16i. The speakers look very similar; like the M16i, the M5i is available in gorgeous cherry veneer or basic black. The price ($899/pair) is $249/pair higher than the original M5. I placed the M5is on Epos's dedicated stands.

The March 2011 issue of Stereophile is now on newsstands. This is a powerful, action-packed issue, and we come at you from several directions with in-depth equipment reports on a wide range of products.