Quote:
Originally posted by BloggingITGuy:
Perhaps you should read my blog post on the subject to get up to speed on what I went through: http://itmanager.blogs.com/notes/2007/12/200-watt-home-t.html

Please note that my experiences are based on direct, repeatable observations of two separate Outlaw 7700 amps, 2 separate B&K amps and my old Kenwood amp. Out of those, only the Outlaw had the problem of the humming transformers that could be heard from my listening position.

I'd also be willing to bet $5500 that the Integra Research RDA-7.1, a very similarly designed amp to the 7700 would not have the same issue in my home.

As it stands, I can only recommend the 7700 to two kinds of people...those who can't get a similar or better amp for around the same price, or those who need an amp they can put into an enclosed rack.

All others would be better off, in my opinion, going with a different product.
I don't doubt your experiences. Some transformers are more prone to being influenced by high AC line distortion than others. I _do_ know however that the transformers in the 7700/7500 are not built to any lower of a standard than those from any other manufacturer - there were no "compromises" involved in it's manufacture for cost reasons.

I'm also quite sure that if you placed distortion analysis equipment on your AC line, you'd see that you have abnormally high amounts of harmonic distortion in your location. This mainly comes from the pole step-down transformers, and is aggravated by heavy loads from people who share that transformer or ones upstream.

If it was such a universal problem, everybody would have the exact same experience, even those with clean AC service. The fact that the problem is as scarce as it is and that there are many who don't have this problem, points to the quality of your AC line.

The B&K amp you have is simply more tolerant of line distortion, nothing more.