EMI/RFI Absorbers

Cream is for pasta Alfredo sauce only. :wink: please see my explanation to @dchang05

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@Vmax, here is the interior of my Lumin U2 transport (the term Lumin uses):

Now I have a new 3M 7050 absorbent sheet. Does it make sense to cover these retangular chips with it? It made noticeable improvement on DS before.

Iā€™d make sure you know its sound signature. I would then give these coverages a try.

Cover all chips on inputs you donā€™t use. Likely they are active and radiating.

Next this square chip and 14pin J legged

These 4 on daughter card

These two 32 pin

Next these small 8 j leg devices in DC power circuits. I had great luck covering these in a a HDPLEX300

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Interesting. I would be interested in before/after pictures with the 3 M absorber. The chips canā€™t get too warm as a result? Should I also get absorbers to stick the switch and the digital part in my preamp and streamerā€¦:thinking:

Great! I have a bit of free time this afternoon, and I will give it a try. Thanks! :crossed_fingers:

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I have done chips in my streamer and switch. I have not pursued my preamp since it has boards that install into a backlplane that I would have to pull and reinstall.

I pulled the cover on my Lyngdorf Integrated to discover use of absorber over noisy parts and toroid. It was built in 2014.

Iā€™d mention that one of the most effective places I found to use EFI/RFI absorption was in our main fusebox. I cut a sheet of Stillpoints EFI/RFI cloth the size of the inner fuse panel, draped it over the breakers, and just held it in place with a bit of duct tape. Quite effective.

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After removing 19 screws I was able to open it up:

I added all the 3m absorbent according to @vmax instruction. t
There is a little hard-to-see FPGA chip on top left corner that was not mentioned, and I cover it too. I also put a 3M tap below the ribbon tape from the front display. The end result is like below:

Now it is time to put it back to hear how it sound.

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Do you also use the thick 7050 for masking the chips or would another film be more suitable for this?
Is it necessary to stick the film over the entire component? Would covering only half or a third work?

3M 7050HF is the only one I used, and they are sticked to the top of chips. I have played Qobuz for around one hour and the sound is just starting to sound good. I am hearing cleaner sound, and a tighter bass. However, it seems the soundstage is a bit flat. It probably needs more time.

Lumin U2 has implemented many noise islolation design in this unit, and I do not hear a big SQ difference (DS had more SQ change). I am thinking to remove some of the absorbent on chips later. It seems to lose a bit magic somewhere, or it just needs more time to settle.

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I find the idea very interesting and will follow it closely.

Oh oh starting to sound like my master fuse experiment. Iā€™d pull that master fuse and drop in an M-1 in the P15. :joy:

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Good timing, I was going to post. This is my final setup:

I kept the 3M absorbents on square chips, and on BNC and RCA inputs that I will never use. So, I removed close to 1/2 of the absorbents. This sounded better than with entire coverage or none. The SQ is better in every way.

Of course, this is by no mean the best layout, but there are too many varibles for me to try. I will settle with it. 19 screws were a work out too. :laughing:

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A positive net effect is a win!

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I put the 3M material inside my Grimm MU1 on all the places it is supposed to go. Totally wrecked the sound like a Master Fuse does. I yanked it all out and it went back to wonderful. I didnā€™t have to return it, I just threw it away. I am not a believer in it.

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Well, did I really hear a better sound than yesterday? I didnā€™t tell my wife of the tweak I made and asked her howā€™s the sound. She said it is sounding a little different. She didnā€™t say itā€™s better. :roll_eyes:

Iā€™ll let it run for a day and listen again tomorrow afternoon. It does not sound worse for sure. Why does it need 19 screws to secure a cover?

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It is all about placement. I know you can get too much in the wrong areas. But getting it right can add emotion, soundstage and vibrant realism. I will say the master fuse didnā€™t give me more of anything. Whether the effects are similar without absorber I will never know.

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Itā€™s a busy day tomorrow, but it will have more time to settle. Iā€™ll compare with the current layout and without on Tuesday. Hopefully Iā€™ll hear more difference.

Good post @tedsmith

I own a DS Sr. and still have the Bridge II card installed. I also have a couple of good spectrum analyzers, one being an older HP 8591E and the other being one of the more compact TinySA units.

I bought a set of good quality ā€˜near fieldā€™ probes that should be in frequency range. I look forward to probing my DS Sr. before and after the removal of my bridge card.

BTW, I do not use the Bridge since I stream through the Aurander.

Cheers from Canada,