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
My questions would be: how loud is the hiss? How far do you have to turn up the volume control before you start hearing it? Is it audible in the range that you use to listen to music? In my experience a phono stage will almost always generate significant hiss if you turn your system's volume control all the way up.

I read about people who can only hear a faint hiss if they put their ear up to the tweeter when the volume pot is wide open. I can’t even imagine how that happens. With every combo of gear I’ve had in my system (tubes, SS, pre/power, integrated, power conditioner, no power conditioner), turning the volume all the way up generates 60-85db of hiss (measured at the tweeter), easily audible from the next room. In most cases with gear I’ve tried, the hiss doesn’t become audible until the volume control is at about 50% (varies by component, of course), which is much louder than I would ever listen.

As long as the hiss is below the level at which you listen, I don’t think you have anything to worry about. You’ll drive yourself crazy (and spend a lot of money) trying to stamp out that last bit of hiss.

Good luck!

Is it equally in both channels?

Does the tube configuration of your amp share a tube between channels, or are they separate/symmetrical?  Can you try swopping some over from one side to the other?

How old are the tubes?  Did they come with the amp?

I feel for you! I hope you get this figured out.  I would not like or tolerate substantial levels of hiss.  I had a problem with a ground hum before, but never audible hiss.  Can you try someone else's amp? 
You'll feel for me more after you hear this one.  So, I'm trying to get my tube amp out of the rack to check out the tubes, disconnected the speakers (or so I thought) and dragged the amp to another rack when my audio physic bookshelves toppled and I got the second ding in a month.  This one to the still pristine speaker which I've had for a month and a half.  Aaaaagh!  I'm beside myself for the second time in a month.  $3000 speakers all banged up.  Will deal with the ****ing tubes tomorrow.  I do think the tubes may be the culprit.  To answer some of the other posts, at low levels I don't hear the hiss, but I know it's there and don't know exactly when it creeps in.  I'm trying to demo a Symposium isolation platform and my heart isn't into it if I don't have a good base level from which to compare.  
Aaaagh!
Consider the ding a blessing!  Now you will not need to worry about dinging your brand new speakers. Rub some shoe polish in it and forget about it.

Also if you cannot hear it when listening to music...