Other people say it works.

I KNOW it didn't work in my system, on ANY of my humming gear.

In my system, this gadget simply did not work -- at ALL. I tried it in various power configurations, in various receptacles, and with various noisy transformers, and it never had ANY effect on transformer hum. I also heard no effect whatsoever on my system performance. I respect the people who say it worked for them, but make SURE you've got an iron-clad money-back agreement and save all the stuff in new condition, in case your experience is more like mine. Gear I tried it on: A vintage Marantz amp. A new H/K high current receiver. A new subwoofer with a noisy transformer. Environments I tried it in: - University tech laboratory, with conditioned power. - Home with A/C and fridge running. - Home w/ appliances turned off. (By the way, does anybody know what's inside this device? Anybody taken it apart? )

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various line conditioners

effectiveness, price

none

I cannot emphasize how effective this product is. I am used to power conditioners that make only a subjective difference, but this one is different. The power in my neighborhood gets very polluted, especially at night, and it caused the transformers in my Krell amps to hum audibly, to my distress. After extensive searching on the internet for a solution, I came across some articles mentioning that the Ah! AC Offset Killer gets rid of transformer hum. I really didn't believe it. The Ah! site, half in Dutch was intimating. I wondered "What am I ordering? This device seems awful esoteric." But for $200 I figured I would take the risk. I contacted Ah! and they told me about a reseller in the US and I ordered it. It came two days later and it worked! The name is accurate in that it successfully KILLED the hum. I could hardly believe that such a light weight, inexpensive device could clean up the AC in such a miraculous way. Hum really bugs me, so to me, this device is incredible.
I want to add that I do not believe the hum is a Krell problem, but rather a problem in the power grid. The hum was non-existent at certain times of the day, which led me to believe that power grid conditions changed at different times of the day. The AC Offset Killer effectively eliminated the hum caused by the polluted power grid.

--Daniel

Similar Products Used:

tara labs power conditioner

Eliminates transformer hum

none noted

I had this intermittent annoying transformer hum especially in the evenings. I thought having a dedicated 20 amp circuit for my amps would help but it did not. I read the reviews on this device and for the price I thought I would give it a try. Since I installed the unit I have had total silence. I have not noticed any sound degradation and I am very happy now.
system:
sony scd-c555es
pass labs x250
pass labs x3
aragon soundstage
B&W 803 nt
B&W 805 nt
B&W htm1
klipsh sw300
mitsubishi 55805 hdtv
mitsubishi sr-hd5
mitsubishi 6000 dvd
Cables, etc: for front 803's kimber select 1120,1020,bifocal-xl, coincident power cord for amps, everything else wired with bettercables.com (good products and service for the money). AH! AC OFFSET KILLER for amps.

Similar Products Used:

none

simple

???

What can I say? It works. Without offsetkiller my amplifier (Aragon) hums. With offsetkiller it is dead silent. I like that. I have the feeling I hear more detail. Sound is more "silky" without losing any dynamics. Great product for little money. Thanks to INTERNET I learnt about this product.

Similar Products Used:

none

very simple: it works

none that I know off

This is a unique device. It eliminates mechanical transformer hum. It makes your system more sweetsounding. It is said to protect against overvoltages. And ... for what it all does, it costs NOTHING. You hear that? NOTHING! If all manufacturers I owned products from in the past, had used this little device, my life would have been a lot less stressed (as hum stresses me). Very, very good product!

Similar Products Used:

none as none exist as far as I know

Cheap

Decrease of depth of image, decrease of dynamics when used with amplifier

I have my offset killer for two years and have used it in several siutations with several components.

Recently I disconnected the offset killer and I my dynamics and depth of image increased with a giant leap.

I now only use it with my DA-convertor but I am not sure whether there is a positive effect. For several components it can be worthwhile (especially due to the moderate price) but be carefull when you use it on amplification.

Eric

Easy to install

Must supply your own power cord.

If transformer hum is driving you slowly insane, this works!..4 stars for value because I believe there is a similar product from dc audio that does the same thing for less, however I have never tried that product. This one works, if it can kill Rotel hum, which it does, it can kill anything. 5 stars overall because it does what it is designed to do. It is the transformer hum eliminator !

Similar Products Used:

Power conditioners

A netfilter story ...
During the last few years i have had problems with sometimes noisy transformers mainly from my power amplifiers. Since i bought my new amplifier, the Class D 300 Watts Spectron which probably has a rather large transformer, i frequently hear a rather loud mechanical 50 Hz hum originating from the Spectron even though i use a (rather expensive) netfilter from "Van Medevoort". My previous power amplifier, a Nelson Pass Aleph 3 had the same problem, but not so loud probably due to the smaller transfo. Another amplifier i had a year ago, the Rotel RB985 THX 5 channel power amp with a 1000 Watt transfo also had the same problem.

I suspected that this mechanical 50 Hz hum was probably the result of impurities in the line voltage. Since the hum is sometimes rather loud and disturbing my listening pleasure i decided to look for a solution.
During my search, i came across the "AC Offset Killer" from AH!, the same people who make the AH! Tjoeb99. Because this filter is not too expensive (about US 175,-) i decided to give it a try. I bought it an i installed it yesterday. I have put the filter in front of all my audio and video equipment, not only in front of the Spectron.

So, what is the result ? Wow ! The sometimes rather loud 50 Hz hum is completely gone. The transfo is also much quieter now than before. What an improvement !
But what happened when i first listened to some music after installation of the AH! AC Offset Killer ? WOW again !!!
The overall sound has really improved although the sound was already very good IMO. Soundstage is larger and better defined, bass is more defined, the silent passages are more silent, the complete image is more refined, ... . I did not expect this level of improvement. I only expected the 50 Hz hum to go away, which it did, but i got a significant improvement in sound quality on top of that.

The associated equipment:
Pioneer DVD 717 dvd player used as transport
Sony TA-E9000ES 96kHz/24bit preamp - D/A converter with firmware version 1.10c
Siltech FTM3-G3 silver interconnects
Spectron Musician power amplifier
Dunlavy Athena speakers
Dunlavy DAL Z6 speaker cable
AH! AC Offset Killer

BTW, the filter is very flexible too. It is small and has one mains input and one output, so you can attach your own power cords.

I want to congratulate AH! for making a really good, not expensive and flexible netfilter. I think i am going to buy me another one to experiment a bit :)

Erwin

high-end results while it is not expensive at all and works!

none as far as I know

I absolutely agree with most of the other reviewers! It totally killed the hum of the transformer in my Classe amplifier. I have no experience with the said protection against overvoltages and don’t look forward to that. I just trust it will work in that case too. As for sound: much more pleasant and natural highs than before. I use it in combination with LS Noise Killers. I once removed them and have to confess I could not live without these 2 in my system anymore. Highly recommended, specially as it is deadcheap compared to what it does. If I could give it ********** stars, I would!

Similar Products Used:

Tice (which by the way did NOT take the hum away!)

It works! Is NOT expensive! Simple to install. Has saved me thousands of dollars (compared to my neighbours).

None as far as I know.

I have to confess that I have been damned lazy and that I feel guilty about it. Lazyh and guilty as I did NOT sent in my review immediately. After I installed my two offetkillerfilters (10 months ago I believe) I noticed that my little Krell lost his annoying transformerhum. That pleased me a lot as I had tried everything I could think of to get it away. Mechanical internal damping, different feet, outside damping with tons of books and magazines: it all did not help. I also have the feeling that I can play louder and that I am no longer getting tired of listening. All very satisfying. Last week we had horrible thunderstorms and of course I did not disconnect my system and antenna-cable. Same case with my neighbour. In my case it was only a burnt out TV and a burnt part in my offsetkiller in his case his TV and his full stereo system burnt out because of the storm. We calculated that these little filters saved me about $5000.- of damage!! THANK YOU!

Similar Products Used:

Some filters as sold by computershops, which did NOT work at all.