DA&T AC Filter Impression
Dec 21, 2013 at 2:51 AM Thread Starter Post #1 of 18


100+ Head-Fier
May 26, 2013
I have thought hard before writing this review whether this is the right time for it as I am still waiting for an important piece of my set-up puzzle, the DNA Stratus. But heck, if my current less-than-perfect set-up can yield a performance that I have never experienced before, I have no doubt the Stratus can only enhance the performance in the end.
The product I am introducing to you all today is the DA&T AC filter. I bet most of you now must be scratching your head and wonder what the hell is this since you probably have never heard of it before. Unfortunately for most Head-fiers, it seems that the influence of the DA&T AC filter has been limited to just a few Asian countries mainly due to its distribution and the lack of information in English language. This is a shame as what I have experienced with this filter is pretty amazing. (I am sorry, but I will try my best to include as few hyperboles as possible)
My less-than-perfect set-up consists- Modified Mac Mini with PSU (Pure Music 1.89) -> AMR DP-777 -> Ifi Tube Buffer (Important for use with Objective 2 amp, I wouldn’t not bother listening to the O2 amp without it) -> Objective 2 amp (the bottleneck here) -> HD800 (Stock cable, can’t use my Moon Audio Black Dragon V2 XLR with the O2 amp). Currently, I am using the balanced power conditioner designed by Sound Affairs Audio for the DAC on one power line and on a separate power line, the PSU for Mac Mini taps power from a IsoTek EVO3 Polaris distributor. On top of what I have, now I placed one DA&T filter after the power conditioner to the DAC and one DA&T filter after the Isotek distributor to my PSU to Mac mini.
The DA&T AC filter is developed in Taiwan  http://www.da-t.com/Product/AC-FILTER.html , sadly almost everything on the website is in Chinese, and google translate can be a bit tricky with Chinese. Another place you can look for more information is my local audiophile forum which most/all are using the filters for their speakers set-ups, just pardon the local flavor in the language. http://www.xtremeplace.com/yabbse/index.php?topic=130588.0
The technical details of the filter are all in Chinese, a pretty long passage on it. I think it basically works by reducing EMI influence on sound. Actually I am not too concerned on the technical details or how it works as long it WORKS. To cut things short, what the DA&T filter does is that it improves the transparency of your set-up without affecting the dynamics, which can be a problem with most power filtering products. After putting the DA&T filters in the chain, I started experiencing everything that comes along with improved transparency, namely details, larger soundstage, better imaging and all these add up to a much realistic sound. What the filter does is unveiling the music, bringing you much closer to the music (live music as one may say). I am sure most of you understand what I mean when we say a veil is taken off in the sound, and that’s what it does.
I thought I have owned pretty decent gears now and in the past, and I should have heard high end music, but sad to say with all the gears I owned, I have never gotten so close to the music (yes, despite the O2 amp bottleneck in my current chain). I continued to discover new details with every track I play and for the first time in my life, I listened for 5 straight hours. I had to stop as it was already 3 am in the morning. Yes, you get this experience generally when you upgrade your gears, but I am not sure if you have ever gotten such good results from something so cheap. I thought the difference in sound was very obvious, like going from SD to HD definition, so it is definitely not a placebo effect. The fact that I already have a power conditioner in place and the AC filter is still able to improve the clarity and reduce the noise level to another level, is also quite mind blogging.
I bought 3 filters in total with the intention to use one for the DNA Stratus when it arrives. After reading that the filters can actually be connected in series to generate a better effect, I put the extra one in series to go to the DP-777 DAC yesterday. And… you can imagine my jaw drop when I heard the combi. The transparency went up a notch again, but immediately I felt sorry for my wallet. This series combi is not going anywhere, which means I am going to buy at least one more filter for my amplifier. (I just placed my order for 2 this morning)
My filter is actually a modified version as my local distributor modified the connector. I am not sure what the difference in sound is between a normal and modified one, but based on the local forum, the modified one seems to sound better. For me, I didn’t want to take the risk, since the difference in price is quite small compared to my other gears.
I bought my modified filter for $280 SGD (~ US$220), while the normal one should costs ~ US140. In case anyone is interested, I have checked with my local distributor, he said the filter is compatible with US power voltage and he does international delivery, so I put his contact below. I am not affiliated to my local distributor in any way, just a highly satisfied customer, who wishes to spread the information of this special product to all my fellow head-fiers, who are in the same journey as me to get closer to music. I hope if you ever get the filter(s), you will share the same positive experience and take one big step towards our common goal.
P.S. Here is the link to my local distributor http://www.skyaudio.net/location.html or skyaudio@singnet.com.sg
Just a note, I have no idea what his charges for overseas delivery is and his response to emails, all I know Steve is nice person to work with, as mentioned in my local forum too.
Dec 21, 2013 at 4:01 AM Post #2 of 18
Interesting product! Will definitely look into it. Just a quick question, do you feel this filter will help even if I already have a power regenerator?
Dec 21, 2013 at 5:01 AM Post #3 of 18
Hi Greed, I wish I have the answer, but I have no personal experience with power regenerator. I will direct your question to Steve and hear what he says.
Dec 21, 2013 at 7:12 AM Post #4 of 18
Hi Greed, got a reply from Steve. Yes, the DA&T filter will still improve the sound even with a power regenerator already in place. If you are considering the filter, I will say get as least two, so you can play around with the combinations and find out where in the chain works best for you and can also try out putting them in series. The highest number of filters I read from my local forum is 13 for his speakers set-up. I thought that was a bit over-kill.
Dec 21, 2013 at 12:23 PM Post #5 of 18
Thanks, yea there is limited info out there and as you said most being in a different language. I might try them out after the new year. I have a ton of stuff incoming early next year. Which means lots of saving until then!
Dec 21, 2013 at 8:02 PM Post #6 of 18
Yes, I understand the big leap of faith due to the lack of info and your incredible amount of new stuff that is pretty overwhelming. It definitely makes sense to sette down on the gears that you eventually will keep before trying out even more new things :)
Dec 21, 2013 at 8:08 PM Post #7 of 18
Yes, I understand the big leap of faith due to the lack of info and your incredible amount of new stuff that is pretty overwhelming. It definitely makes sense to sette down on the gears that you eventually will keep before trying out even more new things

You don't even know the half of it... 

(More to come...)
Dec 21, 2013 at 8:50 PM Post #8 of 18
Ha,ha...I guess just comparing the gears and writing impressions are going to keep you very busy for a long time, very happy problem :D
Dec 21, 2013 at 9:43 PM Post #10 of 18
You can't put a 10 pound filter in a 5 pound box and that's no 5 pound box.
Yes, it looks like a toy.

I am glad it is that small, otherwise it will be really tough to include 4 to 5 of them in my system, considering my DP-777 and incoming Stratus are already quite sizable :)
Feb 8, 2014 at 1:59 PM Post #12 of 18
I believe the DA&T filter is meant to cut down the noise due to EMI and RF interference on the power. I am not sure about white noise and its source, sorry.
Feb 8, 2014 at 8:09 PM Post #13 of 18
I believe the DA&T filter is meant to cut down the noise due to EMI and RF interference on the power. I am not sure about white noise and its source, sorry.

Thanks for your reply!!
Which kind of noise is EMI and RF interference on the power?   Is it usually consistent "hissing" sound (not low frequency humming)?  Does it persist with all signal input disconnected and volume turned down to 0?
Feb 8, 2014 at 8:18 PM Post #14 of 18
I don't think it is exactly that audible noise you can hear when compared to the system being switched off. If you understand a lower noise floor when playing music or an inkier/ blacker background, that is what it does. It does not reduce, let's say audible noise from tubes. So if you are talking about a hissing sound in your system, I'm afraid you got to find out what went wrong in your system, whether it is an impedance mismatch or bad tube. The filter probably can't solve the issue.
Feb 9, 2014 at 7:07 AM Post #15 of 18
If I can be sure that all speakers of the same model produces the exact same hiss with just power connected and volume 0, non-standby mode,     and that the hissing noise sounds noticeably more audible in my house than at the dealer's shop,  is this enough to narrow down the cause of the hiss?

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