Thought on quieting an amp

[Kingrex]

I don't know how, but it is screwed to the aluminum top plate but my fluke reads an open circuit. It is not grounded.

 

[morricab]

The hum is from the speakers. Loud enough to be heard at the listening chair between songs. At night when the power gets worse, loud enough you hear the stereo when muted and the tv is on. Or just in quiet passages in songs.

Please dont start with ground loops in my system. I have tested this with all my stereo gear, accept for the amps turned off, unplugged and the amp inputs shorted. I am focusing my attention on the amps themselves. They need to be not heard at the listening chair when installed as such.

is it still humming when all inputs are disconnected? If not, then it is probably a ground loop and you can try to attach a wire from the chassis of the amp to the preamp and/or source.

 

[Kingrex]

is it still humming when all inputs are disconnected? If not, then it is probably a ground loop and you can try to attach a wire from the chassis of the amp to the preamp and/or source.

Hahaaaaa. Funny. Sometimes we all need a little humor.

 

[BlueFox]

At night when the power gets worse, loud enough you hear the stereo when muted and the tv is on.

That’s interesting. At night the power gets cleaner, and the stereo sounds better, for me.

 

[morricab]

Hahaaaaa. Funny. Sometimes we all need a little humor.

You can laugh but this worked for me when I had a hum on my analog setup. Connecting a wire from the phonostage to the preamp took care of it. There is sometimes a small non-zero voltage between gear when the grounds are not optimal.

 

[Kingrex]

You can laugh but this worked for me when I had a hum on my analog setup. Connecting a wire from the phonostage to the preamp took care of it. There is sometimes a small non-zero voltage between gear when the grounds are not optimal.

I guess you did not read the amp input is shorted and the rest of the stereo is off, unplugged and disconnected as a circuit. Power cords removed from the wall. I even go so far as disconnecting the data utility coax cable from the house. I am not dealing with a general ground loop of component equipment.

I have posted a pix of my fluke reading voltage between the neutral and ground. I get a reading as such at every socket I have ever plugged a meter into. I'm wondering if its possible to rid. Probably take a good iso transformer at your rack and a short power cord from it. Problem with that is large iso transformers hum as the laminatations expand and contract 60 times a second.

I have tried lacing 22awg dead soft silver wire between component and landing them on a brick of OFC copper I drilled and tapped. Poor mans Entrique. Made overall performance worse.

 

[Kingrex]

That’s interesting. At night the power gets cleaner, and the stereo sounds better, for me.

We have LED street lights. I assume my neighbor's have crappy dimmers. The utility did change my power pole 2 years ago. Dropped a new transformer in. Helped some.

It's so hit and miss, utility power. 2 friends house are dead quiet. 3 including mine are noisy as can be. 1 is a tomb but also has a massive Equitech power system feeding it. Also up in the mountains on probably a 5 to 10 acre lot like his neighbors.
The 2 that are very quiet are in planned communities. The 3 noisy are in general suburban city neighborhoods. Mine is 7 miles from downtown Seattle and 2 to 3 miles from the university of washington and all their medical facilities. There are probably a million LED lights that come on at night near me. We probably all share a high voltage distribution. I know of 4 ot 5 substation in Seattle. I probably share on one with the UW.

 

[Kingrex]

Amps are with my local tech. I asked him to try grounding the Cinemag transformer and applying 5 volt dc to the anode. If that does not work they may be shelved, only to play on my 89db PAP trio 10 with Voxativ.

 

[Kingrex]

My tech worked on the amp. Tried a few grounding and more capacitance mods. Nothing worked. Its also a 120 hert hum he said.

Atmashere chimed in and said the transformer and input wires are too long and their is no shielding. As of now, im looking for new amps. I will probably keep these and one day try a metal box and reconfigure the input and shorten the transformer leads.