Anyone with experience with the effectiveness of the AVA HUMDINGER?


Just got a new amp -- Rogue ST 100 -- and have transformer hum.  First time ever in my system.  The factory says something about DC voltage on the incoming AC line.  My son the electrician says he has never heard of that happening.  He says we switched from Edison to Tesla a few years back. 

Anyway, I have tried all kinds of things to see if I could eliminate/reduce it  to no avail:  different circuits, disconnect everything else from the system (other than speakers)  disconnected the powered woofers in my speakers and the subwoofer, tightened the bolts holding the transformer down,  etc. etc.

So maybe the Humdinger is worth a try??   Some other way to handle it (other than a new transformer which the factory says it will do if its really the transformer)?.  Anyone with experience with any other solution?  Thanks for your help..  Regards,  Rich
drrnc2
I tried one on their 30 day home trial basis, but it didn't completely remove the transformer hum I was getting with some monoblock amps, so I returned it.  Since it is a money back proposition, you only risk shipping costs to try it.

FYI, DC definitely can ride on the AC line.  It saturates the transformers and makes some hum pretty badly at times.  My power has had this issue all along, so I have had to select gear that doesn't resonate with this problem.  I am guessing that my situation might be on the more extreme side.

I researched and found plenty of folks that found the Humdinger to be useful, so I'd say give it a whirl.  
Emotiva makes a product similar to the Humdinger. Both are designed to rid the line of DC offset, I believe.
Try it or the Emotiva and if you still have hum, then return the amp under warranty. FYI, in the past, Rogue has installed some bad toroidal transformers in their amps.
Sounds like a great product however i have no hum in my system.

Thanks all for your responses.  I have learned some things.  Right now, I plan to take the amp to the dealer and see if it hums in his set up.  Interestingly, I took the ST 100 out of my system and put an ST 90 (the model previous to the ST 100) in its place---and NO HUM.  Suggests to me its not dirty power, but more likely a bad transformer.  I assume the dealer will hear the hum also and then it will be off to the factory for repair.

Regards,  Rich
Oops!!  Some hum at the dealer, but less than at my place.  He is a guy whose knowledge/opinions on electronics I respect,  and he is honest (therefore I trust him), and he feels the hum he heard was "typical" and not a sign of a 'bad' transformer.  He suggested it not be sent back to the manufacturer, but put back in the system and see what happens. I hope I can get used to the hum (not heard when music playing) and if not, will give a try to the Humdinger or Emotiva unit.  Anybody have any opinion re: effect of Humdinger OTHER than reducing hum, i.e., its impact on music reproduction?  I suppose AVA and Emotiva would say 'none', but wonder if anyone has experienced anything negative from the Humdinger....

Regards,  Rich
I use an Emotiva CMX-2. I have no hum what-so-ever, although I did not have hum to begin with. There is no harm in using this as it does not limit current in any practical sense. Relatively inexpensive and Emotiva regularly runs 15% off sales to boot.
If you have a voltmeter, you can measure (carefully, of course) any DC Voltage on the AC line - it should read near zero when the meter is set on DCV when plugged into a live 120VAC outlet.
Yep, did that and got the zero.

 I still hear the hum and its a hassle.  So I will try the Humdinger or the
CMX-2.
A follow up note:  Got the Emotiva CMX2--while it seemed to improve the sound noticeably, the hum persists.  I have the cover off of the Rogue for increased ventilation/circulation, so hear the hum clearly at the listening position.  What to do???

I am emailing back and forth with the Emotiva folks and they will be making a Dx and hopefully Rx next.