RSA B-52 Hiss question

To those B-52 owners out there, how much background hiss do you hear?  I'm using the B-52 with a pair of HD-800's and I hear some background hiss even with the volume turned down.  Most of the time I can't hear it when music is playing, but during quiet passages it can be a little annoying.  Is this normal?  I ask because I bought this amp used so I have no idea what to expect regarding noise.  Also, I'm new to tube amps so maybe this is normal.  Any help would be appreciated.  Thanks,

will

Hiss with source plugged in or not.  Hiss is there without any volume.  It's not very much, but it seems that an amp at this price point shouldn't have any.  Right?

I'll contact Ray and see if he has any ideas.  As far as the warrant goes, I think Ray's warranty is for 3 years, but I'm the third owner, so I have no idea the age of this amp.

On closer inspection, it is only hissing in the right channel.  I'm going to swap the input tubes and see if the problem continues.

Actually if I change the input tubes, the amount of hiss changes.  I have a pair of amperex which seem to hiss the most.  The stock tubes are the quietest, but the hiss is still there.  I don't have any other output tubes to try so I might have to find another set and see if that makes any difference.  The only thing I could try is swapping the left output tubes with the right and see if there is any difference.

OK, so I contacted Ray and he told me I needed better tubes.  So I have been buying and trying different input and output tubes.  No matter what I try, I always get hiss in the left channel.  The right is always dead quiet!  Any ideas?

Yeah, I guess I'll email Ray and see what can be done.  Like I said, the right is always dead quiet.  The left isn't super noisy, but it is noticeable during soft passages.  It has started to really annoy me!

After re-reading my post, I noticed that I originally heard the problem only in the right ear!  Now I'm confused!  I better be sure what's going on before I send it in! 

I started rotating the 5687's last night and today and I have finally found a combination that is almost completely quiet.  I'm using some NOS Tung-Sol's and they may need some more burn-in to be completely quiet.  But I'm encouraged by the results.  

I think I spoke too soon.  It seems pretty quiet at first, but after the amp really warms up, the left channel starts to hiss again.  I think I'll put the stock 5687's back in and rotate them.  After that, I'm calling Ray if that doesn't help.