Sansui 771 Speaker Hum Question

[gary53]

I have a Sansui 771 receiver (bought in the early 70's) and still works brilliantly. However speaker hum has become more noticeable of late. It is coming from the left channel through all configs. (A, A&B etc). I have disconnected all devices (cd, stereo etc.) and still have the problem. Any help from anyone would be great.

[CDFixer]

It is probably a power supply problem or a bad ground connection in the amp. If it ts progressively getting worse, it is probably a capacitor. Check the ripple on the DC supplies.