[Wayner]

The IEC-13 connector is designed for 120 volt only. Any other voltage is a violation.

[Mark Korda]

  Hi Frank, Wayner, and Everyone,
   I got the Emotiva DC Blocker about a year ago. This was before Franks review of his DC blocker and the Emotiva. Because impressed by his (Frankness) about where their built, price, and what they both did I wish I bought his....anyway...
   Even with the Emotiva in place humming was still there enough for me to dig further. When I looked at that transformer in the middle, the power transformer I noticed there were 2 screws and nuts missing in the middle. I don't know why Dynaco left those out. They were in the transformers design.
     I saw a video once about making McIntosh vacuum tube amps. A worker was pouring black tarish goop into the transformer to lower vibration. I kind of used that idea but instead used a wooden shiv you can get for cheap at the hardware store. It works! 
    I should just get the 2 bolts and nuts and try that but I forgot all about it until the DC hum topic came up. Anyway Merry Xmas....Mark Korda

[avahifi]

I don't remember seeing those center screws used in any ST-70 transformer here, just the four mounting screws at each corner.

Glad the wood shim fixed your issue.

Frank

[rikhav]

Got the humdinger few days back.
My friend would have used it for approx 10 hours and I am happy to report there is absolutely no hum from the amp now
Excellent product Frank
I also feel there should be a jump In SQ as well if it's blocking unwanted DC in AC line.
But for now we are happy that we don't have to hear the humming transformer anymore .

[avahifi]

I have had more than a few clients report back to me that the use of our HumDinger did more than just eliminate the DC caused hum in their power amplifier.

Some said it made a noticeable improvement in the overall sonic quality of their audio system.

One client even ordered several more HumDingers, one for each component in his system!

Frank