HIFI AM radios

[darklife]

I can't seem to find any radios that can reproduce decent high fidelity audio.
Most either roll off the top end or the bottom end, and sometimes both leaving a lot to be desired in the audio.
I would love to find a radio that could reproduce everything from 20hz to 10kHz with a mostly flat response.

I started to build a simple HIFI radio circuit and am stunned at the audio quality of some stations. They sound just as bright and clean as FM stations going through a simple AM detector.
Problem is I can't find any modern radios that do this.

Anyone know of some good books or websites with AM radio circuit designs?
If I could build a simple 5 or 6 transistor radio that would be great. Problem is I can't seem to find circuits that has AGC and other features in them.
The current circuit I whipped together came from the schematic at the bottom of this webpage..
http://sound.westhost.com/articles/am-radio.htm
Any other better designs would be greatly appreciated.

Thanks.