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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
oldears
386 posts
 
I had a BAT tube preamp with hum so bad, I quit using it and went back to SS. I gave it to a tech to check. When I returned home he called and had put it on his test equipment and told me it was better than spec. I told him it was mostly a mechanical hum from one of the toroidal transformers, and he replied," I know about that". He loosened the central transformer bolt, rotated it on axis for minimum noise and gently retightened the bolt and fixed the noise while I was on line with him. I had, like you tried everything. You may be able to do the same thing, with a little luck......or it may be some other problem. This should have no effect on your warranty, but if you have a warranty, why are you worrying about this?
jbhiller's avatar
jbhiller
1,404 posts
 
OP, I think that I'd try what oldears and others are saying.  Rotate the transformer.  If you haven't worked inside an amp before be sure to turn it off, unplug it and let it discharge for an hour. 
cytocycle
1,043 posts
 
Based on the DC stuff not working, I am not sure my Transparent Reference Powersisolator MM Power conditioner will work.  So if you can borrow one great but it's a lot of money.  Mine is the older series and I didn't find the equivalent on Transparents site  http://guildfordaudio.co.uk/transparent-audio/product/369-transparent-audio-powerisolator-mm-power-conditioner
vgupta74
2 posts
 
To the OP did you ever get a resolution to this issue for the H590?
keoliphant OP
86 posts
 
Yes, amazingly good now. I brought old line conditioner from my currently dismantled home theater setup and it wired like a charm. It's an old Monster Power rack style product from about 15 years ago.

I really like this new Hegel H590. Great 1 box solution.
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