Audible diode noise (?)

[WhopperPlate]

Sorry y’all, definitely deviated from the original subject…

still don’t know what that diode noise is exactly…I haven’t used a stethoscope or anything…

Brewdude , I wondered if it was possibly the power transformer hum but when I disconnected the rectifier from the rest of the circuit the noise disappeared. Also, like I have previously stated, I figure if it was transformer hum all my amps would hum. They don’t, just the ones with 1n4007.

[WhopperPlate]

Electrician arrived today . As I suspect electrical was grounded to water pipe ; buried and corroded .

Installed hooked up 8 ft ground stake , like magic all that interference on the AM radio is gone. not living within that emi soup will Probably improve quality of life.

Guitar still buzzes, which isn’t great, but good news is now the amps have less overall background noise and unplugged is quieter.

Now I am seemingly left with an untenable presence of this environmental buzz . It’s either the neighbors radio towers or the power lines transformers. Probably be easier to fix if i had just made a mistake and had to fix it lol

[stephenl]

SiC Schottky diodes are super quiet. Schottky's reverse recovery time is nearly zero.

[R.G.]

There are several possibilities in there.
If it's really 60Hz, not 120 Hz, a buzzing diode is less likely. That would require only one diode to be vibrating, or two diodes in just the right position in the bridge. Four diodes buzzing probably does 120hz. Even a transformer buzz would more likely be 120 Hz, as the things that move would move on both positive and negative half cycles.
Getting a 60 Hz buzz makes me think that your idea that it's in the electrical power lines is closer. There is a condition where the ground for the house can go high impedance, leading to an unbalanced 120Hz. The USA does not run on 120Vac - it runs on 240Vac center tapped, and we use one side or the other, relying on the neutral and ground connections to hold the center tap in place. If the ground or neutral from the house back to the pole transformer is high impedance, the two 120vac sides can get unbalanced. High current loads on one half can lead to higher or lower "120vac" on outlets. An unbalanced 120vac can make a tranny hum at 60hz.

I wonder if the old mechanic's trick of using a "stethoscope" of a wooden rod or rolled paper/cardboard tube would let you pinpoint exactly which component(s) is(are) buzzing without getting electrocuted.

Hmm. Are all the 1N4007s from the same batch, bought at the same time? Maybe a faulty batch. I've used a lot of 1N4007s and not ever had an audible one.

Kudos for checking multiple possibilities, including an alternate location for the amp. That's good thinking. It's entirely possible that you have two or more issues contributing to this - a buzz prone transformer, a strangely faulty 1N4007, and a funny AC power supply.