Jolida JD-100 New unit with bad HUM.....hum

Mine is dead quiet. Except for a slight tube hiss when I have the volume very exaggerated. e.g. to hear the tube hiss!

If you power down the CDP (with the switch on the front panel) do you still get a hum? Try unplugging the power from the back of the CDP, do you still get a hum?

Hum is usually associated with ground or AC issues. It could be an an internal issue with the CDP.

Hiss, just like tape only much much lower in volume, is typical with tubes. Usually hiss is not an issue, very faint to inaudible at normal listening levels.

Macrophonics, or tube ringing, can be an issue. It can also be a hum (usually not though). Macrophonics occurs when your tubes are being vibrated, either by an outside force or even by your speakers themselves. Isolation feet, boards, slabs, devices, cones, and spikes can all help. I use Vibrapods under my CDP. Place the CDP on a nice sturdy shelf all to themselves. This is better than stacking. Nearby speakers, magnets, or power supplies may have a negative effect on tubes too (although I am not sure of this, other A'goners probably will).

If its humming when its plugged in but not powered up. It is reasonable to conclude that its an AC issue (ground loop). That doesnt rule out defective internals of course.

Do you have cable (video) running into or through this system? If so, unplug it and see what happens.

You say you tried grounding the unit. Without checking any manuals (meaning I could be wrong) did you tie your components together via the chassis'? Off the top of my head, I think thats how it should be done. I'll look it up later or maybe a fellow A'goner who knows can help us with this one. Right now I am making a pot of chili so I can't dig out the manuals just yet.

Dont worry about tube hiss. Unless you have a bad tube, it is so low that you have to turn the volume up well past any reasonable level just to hear it. If you had a CD playing while it was turned up you would probably be well into audible distortion or even speaker damage volume levels.

The Chili came out great. Needless to say I ate to much. I doubt they will boot us for Chili recipes, although if it gives the powers that be indigestion.....Hehe.

If you're like me, I have neat and tidy little boxes with all my leftover goodies. See if you have a powercord without a ground (the original Yamaha PC) and give it a try. Essentially lifting the ground. Of course if you have chased a ground loop off from your turntable you will be well able to track this one down. The AC setup BTW, is much better than mine, I can understand your frustration after such painstaking preparation.

I assume both channels are humming, which rules out a tube failure. Unless they both failed (what are the odds) or a catastrophic failure effects both outputs (I dont know, maybe). You could try out different tubes. I presume with the Mod package that you got upgraded tubes, so you probably have the stock tubes.

After RF hum from the cable, ground loops, and fragged tubes, I begin to run out of ideas. I am sorry you're having this trouble. I agree with Mijknarf, once you get the ghost out of this machine, I think you will be very pleased.

As far as the Chili, its pretty much standard fare chunky style. I dice a couple of Jalepenos and saute them in olive oil in the bottom of the pot. Open a window if you try this. The fumes are distressful to say the least.