There were 3 analog versions and one digital. The SRIII is an
excellent receiver for the money and the sound is quite full. Most
discussions about what makes a good receiver focus on selectivity and
sensitivity. The ability to clearly hear what is being said is at
least as important when id'ing a station and the SRIII shines in this
area. But because they only cost $40.00 expect that the dial will be
inaccurate, controls to not feel like a Sony 7600RG, etc. Here is a
link to a lot of information on the series, modifications, etc. Best
of luck. I'm going to get one to use around the home, while gardening,
etc.
Here is a link with some detailed reviews, lists of mods., etc.