Live with A Hum vs. Buy An Outboard Phono Stage

Newbee,

I shorted the ICs by jamming a piece of tinfoil into a cheapo pair of ICs (very high tech), and then putting that IC into the phono inputs of the preamp, which is a NAD 1155, which is solid state. I'd like to go tubes, but I can't afford it, and I'd need a divorce first.

This may be important in isolating the buzzing noise. Then again, maybe not. I just powered off the B & K amp, and put a pair of headphones into the preamp. There was still a buzz present. That means that the amp isn't the source.

It gets weirder, and weirder. BTW, this morning, I powered off my wireless router, and DSL modem in the slim hope that they were the cause. As expected, they weren't.

Newbee,

The phono input even hums when no phono is even there. After seeing that, I tried the shorted interconnects. When I got no hum then, I proved that the preamp wasn't at fault. I haven't been able to identify an extraneous source, so I wrestling with the question of buying an outboard unit. I may just have the same problem with that, however.

Lee

I thought that the problem may be thermal, that's why it lessens to a degree when the preamp/combo are left on for a while. Now, I have the preamp on a separate shelf. The amp can no longer provide a measure of heat. Maybe a heating pad on the preamp will goose it along. If I want to get the preamp really cold, all I have to do is put it outside.

When I separated the amp and preamp (twice now), they are currently separated by a shelf, and a CD player. They used to be right on top of one another. The 1st time was when I tried to eliminate the amp by connecting my old Carver M-500T. It buzzed like crazy when I did that (3' apart).

Each thing I do requires extraordinary effort. About 5 years ago, I had a massive stroke. The doctors didn't even think I'd make it through the night. Now, I'm chasing little, annoying buzzes. I may have lost a few brain cells, but they weren't audiophile related.

The only moving of the preamp has been to move it to a separate shelf by itself (no discernible difference). When I connected different amp, they were about 3' apart. No difference then either.

This morning, I put a metal widow screen behind the stereo to act as a shield, hoping the noise was coming from that direction. It was a no go.

After looking at the website, I'm wondering if I can anything like that at Home Depot, or Lowes.

An Update - which I hope is final.

The hum doesn't appear to be grounding related. Instead, it appears to be thermal in nature. If I turn off the amp, but leave the preamp powered up, there doesn't seem to a problem. For 2 days in a row now, there's been no hum.

If it ain't broke, I won't fix it.

Thanks to those who helped.

Lee

The problem appears

Mapman,

Actually, I don't need the amp on to play the stereo, I can use headphones! With the amp powered off, and using 'phones, I heard the hum. After about 1.5 hours, the preamp must have warmed up enough to kill the hum, because it did go away. Hence, my theory that the problem was thermal.

Lee