Source for information on vintage stereo equipment

Having a beer budget for stereo equipment, it follows that I maintain the same beer budget for other things in my life, like vehicles.  As for cars and trucks I did pretty well thanks to Hemmings Motor news and its (now defunct) magazine Sports Car and Exotic.  The magazine often featured overlooked cars that scored well with driving the enthusiast, and offered affordability.  

I really enjoyed the Absolute Sound's book on electronics and wish there was a monthly publication either print or online that reviews older equipment.  Ideally it would look at an amp for example, offer advice on its performance, what to look for repair wise, average high and low prices and a history of the people who developed the product.  I really enjoy the back story.

Does anyone know of a source for information, like I describe, on older stereo equipment?

By the way I listen to music on:
1980's Superphon amp
1980's Audire Diffet, Legato preamps, and Model 2 amp
1980's Magnepan 1.4 speakers
1980's BW DM-1400 speakers
1990's Harmon Kardon TT

All good stuff that continues to sound great.
I may have a answer for you and this info go's back to the 1940's. I found
a wealth of info on audio equipment. so much that I down loaded the 
the articles from magazines and comments from manufacturers of the product they have brought to market, like a talk with Rudy t Bozak or Sal Marantz. So try look to your left and scroll down to H click on the picture and you will see the first year the magazine was published and all the months it came out. enjoy!!