[Premium-Rx] 591A pre/post selector

[Larry Strong]

Recently acquired one and don't have a manual for it. On the front has 
bypass(assuming you are bypassing unit?), low gain, high gain, high gain 
remote. What is the high gain remote (light comes on remote and high 
gain). What is the high gain remote? It works that way so I'm not sure. 
Any help would be appreciated for an explanation.

Regards
Larry Strong