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Help - I've Got the Dreaded Transformer Growl....

I'm on week 3 with my new office amplifier - Hegel H590 integrated amplifier driving KEF Reference 1's. Absolutely killer thus far. Dynamic, powerful, detailed, smooth and dead quiet at the speaker. One problem - the amp sometimes produces a buzz/hum at the amplifier. It's typically dead quiet during the evening/weekends but buzzes during the day. The Hegel is dead silent at the dealer so he’s telling me that I either have DC on the line or excessive harmonic distortion on the power line. The dealer says that it’s time to go for a power conditioner.

I’m considering the following power conditioners:

1. Audioquest Niagra
2. Shunyata Hydra or Denali
3. Torus RM 20
4. PS Audio P15 or P20

Does anyone have experience with transformer buzzing caused by DC on the line and did the power conditioner properly address the issue? Also wondering if I should first try the Emotiva CMX-2 AC line filter with DC offset eliminator. A very cheap option at $129. Anyone tried one and did it work and/or degrade your system sound?

Thanks for your help!Ken
keoliphant
7 responses Add your response
atmasphere's avatar
atmasphere
7,068 posts
 
DC on the line is not expensive to fix and you don't need a conditioner for it- just a DC Blocker.

That is likely the number one reason for transformers (in particular toroidal transformers) getting mechanically noisy.
keoliphant OP
48 posts
 
Thanks atmasphere - any recommendations for a quality DC blocker / line conditioner?
livin_262002
101 posts
 
As Ralph  mentioned you need a DC blocker.  I have a PS Audio UPC-200 HB (Humbuster) version. It works great. I also have a DIY single outlet DC blocker.
cytocycle
1,034 posts
 
If you do for a Filtering Power conditioner I found my Transparent Reference PIMM 2 eliminated the transformer hum in one of my amps that you could hear in the next room.  My Shunyata V-ray didn't remove the Hum.  Try a DC blocker first it sounds like. Office power is polluted with all the computer gear interference. 
erik_squires
5,268 posts
 
It's really just two choices. DC blocker or balanced power conditioner.

I prefer Furman for all things conditioning, because I knwo their filters so well.

Best,
E
keoliphant OP
48 posts
 
Thanks for the responses. I went ahead with the cheap option first - purchased the Emotiva CMX-2 AC line filter with DC offset eliminator ($129). Fingers crossed it does the trick. If that doesn't work, I'll either (1)  look at the Furman power conditioners or (2) become a vampire and only work in the evenings and wee hours of the night when no amplifier buzz is occurring!

I'll let you know.
oldears
208 posts
 
I'll submit a 3rd choice. If it has a toroidial transformer, see if you can find a technician to reorient the transformer to a minimum noise position.
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