Anyone know about Amber Electronics amps?

I still have a Series 70 (from my college system) and want to get another one for biamping my "outdoor" system.

What is the difference between the Series 70 and the Model 70?

Where can I get info on these vintage amps?

Call 650-834-1614. it's a current posting on in the san francisco bay area. here's the link to the ad:
good luck.