For me it is clear.
The Spectral transformer does not represent the quality that they say.
Especially the European version.
I'll try 2 different DMA 100S and they both buzz!
I was still hoping that a technician from Spectral react on this item.
The Spectral gear is the most expensive gear in my home and the only gear that buzzes.
My Rotel HT gear is qiuet!!
I agree but the problem may be that it is operating within tolerance as far they are concerned, but their view could be it is just not coping with something that is not their fault related to the house.
Its frustrating and annoying (and as I mention I am in the same boat with an expensive transport from a different manufacturer).
If you listen carefully to other equipment such as TVs,etc you may notice a buzz even there for some of the products - I have a few others that I feel are too noisy such as my plasma tv.
But this is no excuse and it will be interesting what support is given by the dealer/manufacturer-Spectral.
I doubt I can give my Pioneer screen back due to it its noise being greater at my house, but then that is still not as expensive as Spectral or my transport.
To get any joy, a full test-monitoring may be required to measure any mains issues and whether they are within satisfactory levels (such as how bad is DC Offset or the mains sinewave,noise,etc), this could help in arguing a case with the manufacturer.
But hoping it does not need to go that far for you guys, or if it becomes too much hassle either sell the gear or wait and see if a new solution coming around in 2-3months helps.
I am being pragmatic that in my case it is going to be too much hassle but will still communicate with my dealer-manufacturer about the loud buzz.
Keep us informed how it goes with the Spectral gear.
Thanks
Orb