Okay the input jack on my seventies Peavey amp here:
Attachment 222619
recently separated from being tightened over the years.
Anyway, this amp has 2 channels, one with the equalizer and distortion and a normal channel. It also has inputs to run both channels in Parallel or Series too. The jack that failed is the primary #1 input on the effects channel.
I was just going to replace it with a regular 1/4 inch jack that I have laying around but after opening it and inspecting it, I noticed that it had a switch that shorted the 2 leads together whenever a cord wasn't plugged in. I thought better of using the jack that I had and ordered a 1/4 inch jack with switch from Fliptop.
Why would the amp want the input leads shorted together if nothing was plugged into that input?
The amp seemed to work okay the times I used it just going into other inputs...