This is my Pioneer SX-770 that I restored. The biggest mechanical challenge was replacing the bulb in the dial pointer. I also aligned the tuner. All signal path capacitors were replaced with Nichicon KL low leakage types. All of the other electrolytic capacitors were replaced as well. Some slight modifications were made, such as swapping the position of the 27K and 33K feedback resistors to take a couple more dB of feedback after the coupling capacitor but keep the overall gain the same.