Dealing with transformer hum

Interesting ideas. I don't know how thrilled my parents will be at me cutting off their electricity for my late night listening sessions. Hopefully they have some candles nearby or something. I kid.

Thanks for all the input. Like most Belles users, I really love my amp, save for this one annoyance that I can hopefully solve.

I have some Quiet Line (by Audio Prism) on order as my dealer recommended placing these on the same outlet as my refridge (which causes a humming/hiss in my speakers) and he also said anything ciruit that has a motor in it... so I'll have one on each outlet for my stereo and one in every circuit in my house to help keep things as quiet as possible.

I had hissing and crackling in my speakers and tracked this down to my computer equipment (that's what I do for a living so I have tons) and I researched it hear on audiogon and some people suggested putting my Ultimate Outlet in front of my computer equipment to keep it from poluting my ac lines, and sure enough I stuck it before my UPS and suddenly I had quiet, I have a little bit of tube hiss right now that I didn't have on another circuit in my house so I can't wait to put the Quiet Lines in to get to that next level.

I had this problem with Cary monoblocks once. FIND THE LIGHT DIMMER IN YOUR HOUSE! When the lights were dimmed, meaning resistance in the AC line, the transformers would buzz like crazy. That was the problem for me, anyways! Good luck!

Actually, the reason the transformers hum is because DC is getting on the primary of the transformer.

Here is a little quote by the one and only Nelson Pass (my hero) :

"If you are experiencing mechanical hum from your
transformer, it is often caused by the presence of
DC on the line. Usually this comes from some appliance
using current asymmetrically, such as a lamp dimmer.

The hum comes usually from toroidal transformers, which
saturate easily with DC, and when they recover, they
draw an extra pulse of current, causing the noise.

You can put a pair of back-to-back electrolytics in series
with the AC power line to block this, and it works fine.
Makes sure the current rating of the electrolytics is
high enough, and the they are joined at a like polarity,
such as + to +."

If you trace the hum to the transformer you may want to give the above suggestion a try. I insert two back to back electrolytics on the primary in every amp I build as a matter of design, so I never have to worry about this type of caveat.

Liguy, I'm not exactly sure what these electrolytics are of which you speak? Can you recommend a brand or a site I can look up to learn more about these. They sound very promising.

Thanks,