More tubes usually indicate better radios. A basic superhet should have 5 tubes. Beyond that some radios have push-pull output, extra RF stage, extra IF stage, tuning indicator, extra audio stages..
Sears schematics can be found at the following address. You may want to compare models?
http://www.nostalgiaair.org/Riders/SRC.htm
Norm
:I am considering buying a Silvertone Console on eBay. There are two - one is model # 4589, which is a 7 tube, 3 band console in excellent shape that works, has original finish in great shape. There is also a model 4586, 10 tube, 3 band that works, original finish, ok, but needs a little tlc. Is there really a difference in the quality of the reception or sound between the 10 tube and 7 tube? Guide books show the value higher on the 10 tube, but anyone have an opinion on which is better radio and why? Thanks, Lyonal Lindsey