I have seen other devices that claim to eliminate ground loop hum, and since this is a rather trivial problem to resolve (I wish!) at first I figured that any of them would probably work just fine. But maybe not... You see, the quality of the internal transformers will have a huge effect on the quality of the electrical signal being processed. It is difficult to "get a handle" on both bass and treble frequencies at the same time. So a high-quality transformer is essential for good results. After looking at quite a few of the units offered, I found that the electrical specifications of the Rolls HE18 were very good, with no hype or outrageous claims made. As an engineer, I appreciate that honesty. And a big plus (for me, anyway,) is that the HE18 is marked as being made in the U.S.A. And so, I placed my order. When the HE18 arrived, I was surprised at the weight of the unit. It must have a pair of transformers with a lot of iron in them. This suggests that the HE18 should have good bass response. (Lightweight transformers usually give the sound a thin or distorted bass.) After admitting the attractive finish and the clear silk screening of the case, I read through the instruction and data sheet. Again, my inner engineer was happy to see all the specifications detailed nicely, with the added bonus of the actual schematic diagram included. While most users will never need to refer to the diagram, including it does please engineering types and tinkerers. Thank you Rolls, for that little detail. OK, now for the fun; let’s put it on the test bench and see if the specs are accurate or not. Short answer, they are correct. I have been plagued by an intermittent ground loop hum due to the audio source being separated from the audio processor and amplifier by about 20 feet of interconnecting cable and also by each end of the system being on different power phases and earth ground connections. The hum included not only the usual 60 Hz hum, but also various harmonics of 60 Hz along with other assorted clicks and buzzes from time to time. Connecting the HE18 was simple. I used the RCA connectors since those matched the patch cables I had on hand. Note that you can use either RCA connections or the usual ¼”TRS phone plugs which may be used in either monaural or stereo mode. There is also a 3.5mm stereo input jack which allows you to use a normal 3.5mm male-to male patch cable to connect the HE18 to a computer headphone jack.) One caution – the HE18 is must NOT be placed between and amplifier and a loudspeaker or the HE18 will be damaged. An HE18 that is damaged in this manner is not covered under the 1 year warranty. So, how well does it work? First of all, after connecting the HE18 and powering the amplifier on, I thought the amplifier must have failed, because I could not hear any hum or buzz at all, not even at full volume. Excellent! Score 1 for the HE18. As for the quality of the music passing through the HE-18, I could not discern any difference in the sound with or without the HE18 in the signal path, using either headphones or loudspeakers. And it sure is nice to be able to listen to music now without the constant background buzz and hum. Would I recommend it? Yes. It does just what it says it will without noticeable change in the sound quality and for a reasonable price. Read full review
Verified purchase: Yes | Condition: New
This is a good sounding and economical solution for balancing an unbalanced system passively. The flexibility of jacks or RCA phonos is a plus. I bought it to balance the output of a custom stereo spring reverb system I designed (notorious for picking up stray noise at the output end. This worked a treat. Very nice sounding transformer. Built like a tank. Would be happy to buy another.
Verified purchase: Yes | Condition: New
Rolls Hum Eliminator is a beast at working through the buzz. There are other things you can do or products you can buy, but I highly recommend the Rolls. One of the Best items I have Ever purchased for a sound system.
Verified purchase: Yes | Condition: New
I tried to use this product to remove a slight buzz out of my connection of a turntable to a receiver. the Buzz off made the buzz worse, also created a hum I and i believe damaged the right channel of my pre-amp.
Verified purchase: Yes | Condition: New
Hooked up an amp to receiver and got hum. Found the rolls he18 and stopped the hum.
Verified purchase: Yes | Condition: New
This device does exactly what it's suppose to. We have a long run of RCA cables at 150feet. The 60 cycle hum is completely gone.
Verified purchase: Yes | Condition: New
Work just like described thank you
Verified purchase: Yes | Condition: New
it took the humm away
Verified purchase: Yes | Condition: New
It didn’t serve the purpose we was expected it was just a waste of money
Verified purchase: Yes | Condition: New
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