Am I asking too much?


I've spent the last three days chasing a ground loop/hiss issue.  I have unplugged and replugged every combination possible, have tried different type of grounds to phono stage, tried different phono stages, different lines into the amp, different turntables and still when I crank the volume with nothing playing, have this hiss.  At lower volumes I don't hear it, but if I turn it up, it's there.  I probably would never listen that loud, but still worry that at base levels the sound is compromised.  I've had this system connected for a month and don't know if the hiss was always there, or if, when I had to rearrange and reconnect due to Christmas and the wife factor, something changed.

My system is a Line Magnetic LM216IA tube amp, a Heed phono stage, a Rega Planar 3 TT (which doesn't have a ground wire) which plays to Audio Physic bookshelves and a JL Audio e110 sub. One of my biggest concerns has been the lack of ground with the Planar 3.

My system is plugged into a Torus Power Conditioner, so I thing I have that base covered into a dedicated line.  With all these electrical precautions am I expecting too much asking for a black speaker background?

Will be interested to hear similar ground loop stories or thoughts on whether there are other issues that I haven't considered.

udog
Udog, it sounds like it's a noise floor issue. Your DC likely isn't quiet enough so you are hearing some noise that it isn't filtering out. You have a few options, you can, if you know how to work on audio equipment without killing yourself, add smaller filter caps to bypass your current capacitors. .1 and .01uf may help. One common problem is the heater voltage, it's usually AC. If your amp is push-pull, than only the driver tubes on the input would need to be converted to DC, but AC uses less current as it's only putting out full voltage/current at the peaks of the sine waves, so while you can buy AC to DC converters on eBay, your transformer almost certainly can not sustain the higher current DC supplies, so you would have to buy another transformer just to run the DC which I believe uses 1.8 times the current AC uses, but just double it to be safe. I think 6SN7s use about 1.3 to 1.5 amps AC, so you would want a transformer that can supply about 3 amps per tube. Often that will cure your problem. Otherwise if it's really driving you crazy, a completely new power supply may be needed. Another option might be a new amp. Don Sachs makes an amp that puts out DC that is so quiet that the AC noise is in the micro volts, you can't hear that even with the most efficient speakers there are.
The small filter caps won't help. The heater voltage hypothesis is not relevant in this case. The user is hearing quiescent current flowing through the electronics. This is normal.
So you hear a hiss at volumes you don't listen to and you're  worried about it? HaHa, Ok!
I was way off on the 6SN7 heater current, it's 600ma AC, so if you have 2 you would want a 2.4 amp DC capability but I am a big believer in potential, so I would want 3 amps DC available.
What’s the s/n ratings on your components.   If they are not close that could cause your issue.   Also have you biased the amp?   If not you might want to start there