Completely eliminates transformer noise as advertised plus improves overall sound quality; product value

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Transformer noise is often dismissed as "something you have to learn to live with". In a low ambient noise room, it can be very irritating even if only slightly present. It was gratifying to learn that a very cost effective filter is available that specifically deals with this problem. My experience to date with the Ah! Offset Killer has been extremely positive. It really works as advertised -- the somewhat annoying mechanical hum in my Creek 5350SE has entirely disappeared and indeed I believe (although this is more subjective) the soundstage width and depth and detail in my system has improved in comparison with other power conditioners I've used. I would recommend this device without any hesitation to anyone who has experienced a problem with transformer noise of the type due to DC contamination of the AC mains current (I guess that's what is meant by "AC offset"). Be careful, though, it may not alleviate mechanical noise originating from a poorly manufactured or defective transformer or "electrical" noises caused by ground loops, etc. It would pay to first track down the exact source or cause of the noise problem and then apply the appropriate fix.

Similar Products Used:

Monster and Adcom power conditioners

After having used the AH! offset-killer, for some 7 Months in my system (Krell KAV-300i amplifier, Tjoeb ’99 CD player), here some notes.
Due to the fact that I didn’t have any other line conditioning device to compare it with, I could only assess the effect on sound versus not using anything. I’m living in the centre of Amsterdam, a place with supposedly, a lot of mains pollution; maybe in other places the effect would be different.

1) overall sound resolution increased with approximately 10%. This is really a great effect.
2) the absolute sound level seemed to get slightly higher, clearer;
3) In my room I noticed a very slight change in frequency spectrum, making mid-bass tones slightly more ‘resonating’ in my listening room. I guess this is simply a the increased resolution issue at work (that revealed a flaw in my current system).

Overall sound with the offset-killer is definately better, than without one; this is really significant in MY setup, and in my home.
Taking into account a) it really works! And b) the attractive price, which really allows for cost-effective experimentation, I decided to make it a permanent part of my sound chain.

N.B. I’ve decided to (before further investing in a more expensive line conditioner) further improve the quality of the mains cable that runs to my set. One of my plans is, to make a direct run from the central mains switchboard to the wall socket close to my set. I've read that this can be worthwile to do, and would enable to evaluate line conditioning devices in a better way.

The AH! AC OFFSET-KILLER
Lately it is almost impossible to open a hifi magazine without finding an article about power-conditioning. Since a few years the ac supply (and its related contamination), became a very hot topic and there is more than enough reason for that! Quite some music- and hifi lovers have been in contact one way or another with this subject. Through a conditioner, through ac-cables or both.

The effects of ac-conditioners differ as much as their prices. So a warning is certainly necessary: there is a lot of stuff available, but not all works as it should. My advice is: listen carefully to the result of an ac-conditioner. An ac-conditioner can immediately show several positive effects, like for example a cleaner sound and better detail. But, check the bass and an eventual loss in the dynamics! Often amplifiers are limited by use of an ac-conditioner. There are, but only a few, ac filters that only deliver “pros” for the full system. There are also ac-filters available special for use with computers. These are -as far as for the ones I have been able to try and from what I heard from my friends- absolutely not suitable for the audio use and produce more problems than solutions. In such a case, it can even be smarter to spend a few hundred guilders on a good ac-cable than on an ac-conditioner.

Fortunately there are also very good filtersystems available. Manufacturers like Tice and Transparent produce now for years with growing success good powerconditioners. If a Tice filter gives good results in a set (which is almost in 90% of any case), the difference of a system with or without a filter is very big. If you have read my reviews about the PIXL and PLXL Transparent powercables (visit www.hifi-notes.com), then you know about the wonderful and healthy results you can get with them. However, here you talk about quite some money, which is not always in order with the rest of your components in the system.

Of course you can wonder if there are less expensive solutions available. Well, there are. Think about the wellknown Harmonix AC Enacom filters. Worldwide there must be thousands of people who use one or more of these in their sets. Also with our customers the Harmonix AC Enacom filters are one of the most popular accessories. However this “pole position” is now threatened by the new AH! AC NOISE KILLER (yes, another killer from these peaceful AH! People). Th AH! AC NOISE KILLER does exactly the same as the Harmonix but for half the price! These high frequency filters do their work for a price of only HFL 50,-!

The AH! Team (wellknown for the AH! Tjoeb, the phono-stages and headphone-amps) has designed now a powerconditioner and that’s actually where this review is about: de AH! AC OFFSET KILLER.

This miracle (sorry, I start right away like this) is in a small metal case with one single AC in- and output. The filter has actually 3 different functions of which a short description follows:

1. In the standard supplied AC voltage you’ll often find contamination for which a (toroid) transformer is very sensitive. This contamination influences in a negative way the results you can get out of your system and besides that it can be the reason for an annoying (mechanical) hum, which after some time can irritate very much, specially if you have a very quiet listening-room. If you complain about that at your dealer, very often the answer is that you have to learn to live with that. But in many situations the AH! AC OFFSET KILLER does offer a solution. According to my knowledge this is unique for a powerconditioner. I don’t know of any other powerconditioner with this feature.

2. A highvoltage protection circuit is built in to block high voltage spikes caused by other equipment (or lightning!!). This certainly will give you a safer feeling, although extreme powerful voltagespikes will not be stopped by anything.

3. A high-quality network circuit is used to remove high-frequency "signals".

The result of these 3 filtersystems altogether is that the use of the AH! AC OFFSET KILLER brings quite an improvement of the musicreproduction. You can easily identify the effects that are unbelievable good, especially if you keep the price in mind. Being a ridiculously low HFL 350,- (this is even less than US $ 175.-). It’s quite obvious that this low price has to do with the fact that the “killer” has been developed and built in-house and that no advertisements are made for the AH! Products. It's only sold on recommendation of existing (and obviously) happy customers. Also it’s built into a neat, but absolutely not a luxury cabinet. And in most cases such a filter finds its place behind the rest of the equipment, out of direct sight.

Besides, concerning the price and the housing, for Krell KAV-300i owners there is more good news on the way! There is about to come a special “KAV300i-internal-version” of the AH! AC OFFSET KILLER, which will cost only HFL 250,-, including installation! The Krell KAV-300i owners are in the lucky circumstances that they can evaluate the results with an “external” AH! AC OFFSET KILLER and can order the cheaper internal version, which can be installed by anyone in 5 or 10 minutes.

Which results can you hear? The bass becomes more tight, the placement of voices and instruments improves strongly, the highs become more smooth, but also more clear. There is more air around voices and instruments. Everything, from the lowest until the highest frequency comes out cleaner. Reason why you can listen longer without getting tired. For a try out the best is to start with an AH! AC OFFSET KILLER connected to the cd player and/or the preamp. But during my experiences it has been proven that using an AH! AC OFFSET KILLER with the poweramp also benefits. You want to get the maximum out of this? Use an AH! AC OFFSET KILLER with every component in your system. Specially because of the (low) price, you will not regret the results. To make things easier, a multi outlet version is in the plans.

In short: it’s absolutely worthwhile to give this powerconditioner a try. The “KILLER” is available from DÉ HIFIWINKELS (Beek-Ubbergen and Eindhoven), DÉ HIFISTUDIO (Emmen) and THE HIFISHOP (Tilburg).

PS If ever one evening you have listened “enough” to your audiosystem and you want to lay down on the sofa to let you overwhelm by whatever movie, don’t hesitate to connect your AH! AC OFFSET KILLER between the TV and the AC outlet. You will not know (you will!!) what you hear and see. The A(H!) Team has really created an ultimate multimedia “KILLER”!

Does what it is supposed too.

none at the price

My stuff (big vifa threeway DIY, Cyrus III+PSX, AH-tjoeb 99 CD-player, Norost flatline gold, vdHul patchbay)) is capable of sounding very pleasant, but does not always do so.
Especially during the evenings monday to friday from 18:00 to 22:00 the sound can get a little bright, with loss of articulation, bass and detail, generally loosing it pleasant musical abilities. it sounds it best late at night and on sundays, then the sound can become very good, spacial, detailed, full with silky mid-treble.
This lead me to belief ac-polution might be the culprit.
At least one of my friends thinks it is because of general relaxation, and the beer.
As luck had it, the day I bought the offset-killer, he was visiting my place. So we AB-ed, and it was not the beer. Suddenly the sound regained its friendly full character, spatial abilities with lots of naturally presented details.
Mind you, it is not the kind of difference you hear when you substitute f.i. the amp, the tonal balance stays the same, but edginess and mush is removed and detail improved.
Energy and bass power is preserved, onlike other filters I have tried.

Then, at night the sound became magical, almost palpable and tranquil. Of course that might have been the beer, but since I used the offset killer on my CD-player only, I think my kid might improve even more if I would add another filter on my amp.

Conclusion; if your kid varies in quality and there is some regularity in this, chances are mains pollution is the culprit, in which case the offset killer is likely to do what it is supposed to do, without any added disadvantages.

Similar Products Used:

Some not to expensive filters.