I've been following an interesting thread on the Linn forum (https://www.hifiwigwam.com/forum/topic/ ... hronicles/)

Has anyone investigated using EMI shielding inside a HAKAI? I am considering testing this product:

https://www.mouser.co.uk/ProductDetail/ ... EShA%3D%3D

My thinking is to use the shielding to minimise EMI between the SSD, the motherboard/CPU, the ATX power supply, and the power cables.

I think I can do this with minimal interference with air flow, so should not cause over heating. The case stays pretty cool.

This pic shows the interior.

This is a useful explanation of shielding that provides clear advice on how shielding works and consequently how to shield effectively : http://learnemc.com/practical-em-shielding

What case is that: looks similar but different to my F1CWS Evo - have you modded yours, and where are you thinking of putting the EMI shielding?

tokenbrit wrote: ↑2021-02-09 14:48 What case is that: looks similar but different to my F1CWS Evo - have you modded yours, and where are you thinking of putting the EMI shielding?

It is a case from RGeek. I haven't made any modifications other than controlling cable layout.

I am planning putting the EMI absorption sheet horizontally to cover the entire mother board, about halfway up the case and below the power cables, so it is between the power cables and the electronics. The heat sink, RAM and the power supply will all protrude above the sheet.

I am also planning on sticking it to the bottom of the SSD, separating the SSD and the power cables. The SSD is mounted on a frame that sits at the top of the case, just below the lid.

If I like the sound of these changes. I will also stick some of the sheet to the sides of the case, and possibly figure out a way to place a horizontal sheet in front of the power supply daughter board.

springwood64 wrote: ↑2021-02-09 16:24

tokenbrit wrote: ↑2021-02-09 14:48 What case is that: looks similar but different to my F1CWS Evo - have you modded yours, and where are you thinking of putting the EMI shielding?

It is a case from RGeek. I haven't made any modifications other than controlling cable layout.

I am planning putting the EMI absorption sheet horizontally to cover the entire mother board, about halfway up the case and below the power cables, so it is between the power cables and the electronics. The heat sink, RAM and the power supply will all protrude above the sheet.

I am also planning on sticking it to the bottom of the SSD, separating the SSD and the power cables. The SSD is mounted on a frame that sits at the top of the case, just below the lid.

If I like the sound of these changes. I will also stick some of the sheet to the sides of the case, and possibly figure out a way to place a horizontal sheet in front of the power supply daughter board.

Sounds interesting Pete ,can you do clips if you hear any difference ,better or worse .

Lego wrote: ↑2021-02-09 22:55
Sounds interesting Pete ,can you do clips if you hear any difference ,better or worse .

Yes I will record clips at each stage, and share them here

My Laird EMI absorption sheets have finally arrived. It's going to be a fun weekend for me.

Shielding added.

I did it in two stages rather than fully committing. First I added a shield that sits around the heat sink. This is not stuck to anything so is easily removed. I recorded my tuning tracks before and after this step before deciding to proceed to the next step.

The test tracks brought a modest improvement, so I decided to commit more fully:

• Internally and externally shield the Intel 320 SSD

• Individually shield surface mount chips on the motherboard

• Shield both sides of the 2GB RAM

• Individually shield the DAC chip in the ESI

Before and after recordings here: https://www.dropbox.com/sh/7s4wusjomjxx ... _bfLa?dl=0

springwood64 wrote: ↑2021-02-20 15:03 Before and after recordings here: https://www.dropbox.com/sh/7s4wusjomjxx ... _bfLa?dl=0

Is B before, and A is After? ;)
Quick listen, I found A easier to get into on both - musically tighter; more coherent. B sounded a bit sloppy in comparison, like they were having a bit too much fun at the expense of the music :?
I'm not against fun; it's just that B felt like a party where I arrived late and everyone is drunk already, but I'm not .. yet :p

Hmm... tokenbrit's description seems spot on! I think A is better, but there's a lot of fun happening with B.

tokenbrit wrote: ↑2021-02-20 15:29
Is B before, and A is After? ;)
Quick listen, I found A easier to get into on both - musically tighter; more coherent. B sounded a bit sloppy in comparison, like they were having a bit too much fun at the expense of the music :?
I'm not against fun; it's just that B felt like a party where I arrived late and everyone is drunk already, but I'm not .. yet :p

Ha! Your description is hilarious!

In fact, A is before and B is after.

I used the recordings to judge the benefit, and overall thought the shielding brought a modest improvement.

However I've now had the chance to listen to a few albums. I hear a bit more detail, which is nice. But much more importantly, I'm finding it harder to turn the music down or to resist the urge to play another album.

Playing with Boazu turned up to red/orange there's no hint of the edginess that used to emerge at top volume.

I prefer A on both song. It has more contrast of the melody. B feel kind of flat and more lifeless, harder to follow the tune.

Ken

2B sounds as if there's more of a groove going on compared to 2A

Prefer 1A to 1B

springwood64 wrote: ↑2021-02-20 15:03 Before and after recordings here: https://www.dropbox.com/sh/7s4wusjomjxx ... _bfLa?dl=0

My impression is that B takes it too far. If B is with shielding, I would reduce it to half. If still too much, I would try half of that.

One thing about adding any kind of shielding is that usually the mechanical effects are much larger than the effect of the electromagnetic shielding. And the mechanical damping needs to be just right, not too much nor too little.

It's not uncommon for me to find that if 5 square cm of a self-adhesive electromagnetic shield has a certain effect, the same effect can be obtained with a different material of similar size and weight but with no screening properties.

I really enjoyed seeing the top of your head “bobbing” around in the mirror! :-)

Your system play music in a very enjoyable manner and I would just revert back to normal if it was my system but as you state you enjoy it more now go with your feel and see if it keeps you happy.......

I really appreciate the feedback from people. I removed some of the shielding yesterday evening and the result is a notably harsher sound and a step back from before I first introduced the shielding.

Frederik's point about mechanical effects also made me think. The cable layout in the case is quite cramped and it is difficult to keep the alignment of cables consistent, which may muddy the water between changes.

So: I'm starting again and being much more cautious in the changes I make each time.

This fun.

beck wrote: ↑2021-02-22 10:19 I really enjoyed seeing the top of your head “bobbing” around in the mirror! :-)

O dear - I didn't spot that :)

I took more care with ensuring the cables are separated where possible, and avoid contact with the case.

No other changes were made.

This has removed the harshness I introduced last night.

I have taken the shielding as far as I can for the time being. Along the way I have experimented a lot and ended up making quite a few changes. I am pretty happy with the result.

To summarise the changes I have retained:
1. Small squares of Laird screening stuck on the streamer RAM
2. Small square of Laird screening stuck on the DAC chip
3. Adhesive copper foil wrapped around the streamer AC/DC adaptor and cable (earthed)
4. Removed the Netgear GS108Tv3 switch and Friwo PS entirely, so the streamer connects via wall socket to the Router.
5. Moved the Hakai NAS and power supply downstairs and connected it to the Router. It is now on a different ring mains to the rest of the system, along with the Router.

The changes I tried but ultimately rejected:
1. Sheet of Laird in the streamer to separate the ATX powerboard and the cables from the motherboard
2. Sheet of Laird stuck to the outside of the SSD
3. Sheet of Laird placed but not stuck inside the SSD
4. Copper foil wrapped around the cables inside the streamer (earthed)
5. Copper foil stuck to the inside of the ESI Gigaport HD DAC (earthed, very fiddly!)
6. Adhesive copper foil wrapped around the NAS AC/DC adaptor and cable (earthed) while connected to the same power wall socket as the streamer.

Playground results here: https://www.lejonklou.com/forum/viewtop ... 989#p54989