It all started about 2 years ago when I went to a listening audition with a friend. This was my first touch with audiophile gear. I never knew how good music could sound and I was hooked ever since. I started modestly with a NAD setup and moved up to the system you see now. Musical Fidelity was one of the first audiophile systems I heard and I told myself I would own it one day. Voila!!! I'm exstatic. Learned alot along the way thanks to this website and everybody's help. Also learned how addictive this hobby can become spending almost all my money on this new system. Done some tube swapping trying the telefunkens, the cryo'd EI Yugo's and the original Svetlana's but found the Sylvania's to be the best. Want to try more tweaks in the future but have to wait for more funds ... JohnnyP.
With tubes there is usually going to be some noise. Some more than others. Some are very quiet. I'd say a couple things need to be addressed. the power cord situation for the preamp, and perhaps the need for an electrician to look at the possibility of a ground loop. IF the hissing you hear is only at full volume. . . then maybe not... if it's all the time, maybe so. hissing and sibalence are two different things.. Sibilance is the result of differing ground potentials, and usually introduced by adding cable TV, FIOS communications equip, or the like. It's easy to fix. Constant hisssing is more the result in your system I'd say from tubes and cabling. Just a guess. I posted a thread about sibalence just some months back and got some very good, very cheap info on some fixes. check it out. It worked for me.