[kyyuan]

All,

I've been wrestling with the issue of "hummin'titis" in my system.  Through my speakers, I get a low level buzzing and slight hum.  I've taken a number of steps to address them, but to no avail.  I've tried the following:

- put in a dedicated circuit
- checked the polarity/grounding of circuit
- tried cheater plugs
- "plugged my ears"  --- j/k

The buzz/hum just won't go away.  However, at times, during wee hours of the morning (say 2 to 3 am), those noises go away; I usually try not to listen to music around those hours, if I can help it.  Thus, I think it's the power coming into my neighborhood/house that's causing the problems.  Right?  Bad DC issues from the line?  Is this something that either Alan Maher's products or the Noise Hound from Blue Circle can mitigate?   Thoughts?

Thanks,

Ken

[Gordy]

In my experience, hum from the speakers indicates a ground loop problem.  DC on the line will cause transformers to buzz but, I've never noticed a hum at the speakers from DC.  A simple DC blocker will stop the tranny buzzing...

Have you tried removing/isolating your components one at a time to possibly identify the culprit?

Do you have cable tv/internet tied to the system? 

[kyyuan]

Gordy -- thanks for the quick reply.  To be precise, the noise is mostly "buzz" through the speakers.  I've isolated my components one at a time, but it didn't matter.  My rig is strictly 2-channel, so no HT or anything else tied to it.

[richidoo]

Because you say it goes quiet at night when everyone's appliances finally shut off, it's probably just trashy power. There are lots if ways to clean it up. I won't dip my toe in that tub of hot water, except to say that I have tried a few different things and so far I like Equitech balanced power transformer best. It quiets the power and lets my tube amps sing without restriction. The Equitech tranny itself does mechanically hum very softly though, at least in my house, but Gordy's DC blocker circuit will probably help me on that - someday when I'm not so lazy.    Maybe you can borrow a balanced power transformer to try, or maybe even build you own? 
Rich

[Gordy]

Hi Rich,

The dc blocker circuit was designed by Bryston, as I remember it, and I "lifted" the graphic from a thread that Occam posted it to!

If you do build the blocker, use the two diode drop version as it's twice as effective, subjectively, as the redundo.  35 amp bridge and 3.3k / 35v caps.