Long story short, replaced the rca inputs on the 705x because the outer sleeves fell off but got the neg and pos board connections mixed up. All was fine till I put a heavier and longer powercord on the amp and discovered the amp was not grounded to earth. Fixed that by grounding the chassis to earth. The amp no like, speakers loudly protested, and a puff of magic smoke came out da amp. Think it was a resistor and have since replaced that, now I want to be sure the connections are correct.
R1 to J2 is the positive (center lug) of the rca plug. Got that one ... this time. The chassis and earth ground are bridged at w1, so does it make a difference which lead goes from the board to the outer sleeve of the rca plug or chassis ground?
Shouldn't the chassis be grounded to Earth?
Also need to find a good but affordable soldering iron. Suggestions?