That is likely the number one reason for transformers (in particular toroidal transformers) getting mechanically noisy.
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
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
25 responses Add your response
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. |
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. |
Back to the drawing board. The Emotiva CMX-2 didn't help at all so it's being returned tomorrow. @cytocycle - can you send a link for the Transparent Reference PIMM 2? I'm not seeing anything by that name when I do a web search. @erik_squires - since the DC blocker was a no go, think i simply have dirty power? Do you have a preferred Furman model for power conditioning? My system's at the office. Early morning & late night equals dead quiet. People start showing up, the transformer starts to buzz. @oldears - Interesting suggestion. I don't want to modify the amp as it's brand new plus I don't want to void the warranty. |
It is really weird the DC blocker didn't help. It could be you just have some weird transformer resonance which is better fixed mechanically. The two key features for Furman's are LiFT and SMP. Combined they are the most cost effective noise reduction I know of. Fortunately, this comes in relatively inexpensive models. https://amzn.to/2TzW7q1 Otherwise, advanced models add power regulation, and even balanced power for lots of $$$ though, as well as being more rack friendly. |
keoliphant OP50 postshttps://www.hegel.com/products/integrated/h590 The DC blocker must have an ampere rating as big or bigger than the amplifier idle ampere rating as well as the FLA rating of the amplifier. Check out this unit. https://avahifi.com/products/humdinger-dc-line-blocker Give them a call and ask them if their unit is rated big enough for your amp. If not ask them what they would charge to build you one that is. Audio by Van Alstine 2665 Brittany Lane . Jim . |
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? |
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
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Well, the cooler temperatures of October / November brought back the curse of the transformer growl!!! I picked up the Humdinger DC Line Blocker (https://avahifi.com/products/humdinger-dc-line-blocker) Buzzing diminished by a significant margin. I used to easily hear the buzzing from my desk (approximately 48" away from the amp) and now can only detect the sound when my ear is next to the amp (within inches). Pretty amazing solution for $140. (I am not affiliated with this product). All that said, I've been saving for a power conditioner that specifically blocks DC. Here's what I'm thinking - IsoTek Evo 3 Nova. (https://www.isoteksystems.com/product/select/evo3-nova/) Anyone have experience with this product? I'd love to hear your thoughts.. Thanks!Ken |
peter781 posts I’m already beginning to doubt whether the expensive Titan One will even have the effect in DC blocking it promises.@ peter78 Where does it say the unit has a built in DC blocker circuit? Overviewhttps://www.isoteksystems.com/product/mosaic/evo3-titan-one/ Jim |
I've used a PS Audio "Humbuster III" for my power amps for years, and it works swimmingly. Why they discontinued that thing seems weird but they're still out there, or at least maybe a similar item as discussed above...I've got other DC blocking power supplies here and there and they all help keep the noise down. |
@peter78, pick up the Humdinger DC line blocker. It will solve your problem. The only Isotek product that I saw that included DC blocking capabilities was the Evo3 Nova. I picked one up for Christmas and it works as advertised, cutting dc hum considerably and yielding a dramatically more quiet listening background. I wasnt a believer of power conditioning until actually trying it. |
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I’m using this inline device…allows you to use one cable iFi SilentPower | DC Blocker - Blocks Any DC Offset, IEC Connector https://www.amazon.com/dp/B08XWHJRZ1/ref=cm_sw_r_cp_api_glt_fabc_8ZXFKC2TSDVEWKVD63AQ |