Well I figure that since I have been trying every logical thing i can think of to pinpoint the tempest's hum issues heres some more things to add to the list of "didnt work".
I have been looking at those devices on the market that filter out DC on the AC mains, such as the PS audio humbuster etc. Found a bunch of different schematics on DIY audio forums but one in particular was easy to follow and looked like it was a winner so I decided to give it a try. The commercially available ones are about $300 so if it didnt work I would at least have to send it back during the 30day guarantee. But if it did work I would be out $300 bucks I didnt have!
So DIY it was. Ordered parts, scrounged around lowes and radioshack for a chassis and built it and nada. it DOES quiet the buzzing transformer a bit. Although I can still hear it humming slightly. So it works, It just didnt fix the hum in the phono stage. I knew it was a long shot but figured it was worth a try. I suppose at this point Im just going to call it quits and admit defeat. At least I have another preamp with a good phono stage in it for the blue moon's when I do actually put on some vinyl but I had hoped to get this baby going full throttle.
The idea behind these DC trap devices is that DC riding on the ac line sends the transformer into saturation and causes it to buzz and hum. So this device filters out the DC on the line to prevent that from happening. Anyway, Here's the schematic I found and a couple pics of the one I built. I ordered the 10A rectifiers like it says in the schematic but I should have just went with 35 or 50 amp ones just for the hell of it. I believe the PS audio one uses 50A rectifiers according to their site.
On a side note, I also ordered some Blue diffused LED's to replace the ones in my Khartagos that are just too bright. These new ones are alot better, they are a dark shade of blue with almost a hint of purple and are about a third as bright as the other ones. Bad news is I will actually have to go outside to get a suntan now.
Here's the Mouser part number for them if anyone else is interested.
604-WP7104MBD
